1st revision of 2015 rules released [Archive]

apalrd

08-31-2014, 03:51 PM

There are a few differences:

-The EV rules (in 2014) differentiate between mechanical and regenerative brakes for the purpose of torque reliability.
-The 2015 IC rules section IC1.16 defines a 'brake plausibility device' which is non-programmable (e.g. built from discrete analog or digital components, not a secondary processor) which evaluates only the braking force (the rules say 'for example, >0.8G without locking the wheels') and the throttle position >10%, and shuts down the throttle power and fuel pump power in the event of an implausibility, in a way that is not resettable without resetting the main kill switch. This is extremely unreasonable, as drivers already request pedal when exiting a corner under heavy braking to either fill the manifold (so torque is ready as soon as they need it) or to spool a turbo. This entire brake plausibility device does not exist in the 2014 EV rules. It would be much more reasonable to ask teams to include processor or control system software failures in their FMEA, and design and reliability-test systems which can detect and handle a processor, control system, or software failure. For example, simply by adding an evaluation of the spark advance angle and/or the presence of spark and fuel control, it is possible to run a high throttle % with low torque % due to retarded spark or partial FSO (e.g. running a 4 cylinder engine on 2 cylinders).

JulianH

08-31-2014, 04:01 PM

apalrd

08-31-2014, 04:06 PM

I thought there was a plausability check in the EV rules.
For us it was the "famous" EV 5.6 rule (I still can remember the rule number ;)). We also had to use a non-programmable logic that would open the relays. Still not sure if this is reasonable but should be the same for EV and IC.

But to be fair, we don't have turbos to spool...

It's fair to restrict torque during heavy braking, but not throttle position, as we have multiple ways to control torque and higher efficiency is attained the more open the throttle is (as pumping work goes down). We also have turbo's to spool, which we can do by running a high spark reserve (very retarded spark and increased airflow).

tromoly

08-31-2014, 05:33 PM

Not sure if anyone noticed, but FS Austria is listed in the rules as an Official event, congrats to all involved.

mech5496

08-31-2014, 06:22 PM

I think Austria was official this year as well; might be wrong though...

Rules are..interesting! As a side note to where the rules focus regarding safety should be, please take a look at this:

https://twitter.com/flueglhuegl/status/506176664540565504

08-31-2014, 09:41 PM

Back when I had a job, anyone producing an Engineering specification like these 2015 Rules would be immediately SACKED! So many examples of bad workmanship..... (But how do you sack someone when you don't know who they are, because they keep hiding in the broom cupboard?)

As just one example of this disgraceful work, these current Rules let you have razor-sharp edges ALL OVER your "Aerodynamic Devices" (whatever they are), EXCEPT if those edges happen to be ((forward-facing) AND (horizontal OR vertical)).

So razor-sharp forward-facing edges at some angle other than horizontal or vertical are just fine.

And razor-sharp wing Trailing-Edges are also perfectly legal.

So now that the IRC has made this clear, all aero teams can start designing their TEs to Schick-sharpness (because sharper works better aerodynamically). I suggest a strip of hardened steel (maybe a band-saw blade?) bonded into the TE of the wing. Your gun driver can then get himself into that Zen-zone just before his record breaking lap, by chanting his mantras while honing the TE with a whetstone - "Perfect sharpness, perfect lap... Perfect sharpness, perfect lap...".

Oh, and make sure you bring a copy of the "new improved" Rules to Scrutineering, so that you can prove your car is "legal".

Z

Westly

08-31-2014, 10:43 PM

Generally the diagrams dont show the front wing restrictions particularly well, as the diagrams imply that nothing above 250mm is allowed in front of the front wheels, but the text contradicts this implying that once above the tyres in a frontal view a wing is legal.(The diagram T9.3.2 details that between 250-500 in front of the tyres is restricted, but the text T9.2.2 details that above 250 is un-restricted as long as the forward view of the tyres is unobstructed.) Why not just a blanket restriction on front wing height rather than all this complication?

Cal Simraceway(Berkeley), whats the OD of your 8" wheels out of interest? as this would likely make the front wing little restricted. Also DUT are potentially have little restrictions with their small front tyres?

Will read in more depth when I get home from work.

Westly.

Pete Marsh

08-31-2014, 11:16 PM

Westly, the "general" rules has a restriction above 500mm, making the region above the tyre, but bellow 500mm allowed IMO.

Anyway, for constructive review / editing.....

T3.5.5 the angle of bend braces at less than 45 deg to the tubes bend plane will make the VERY common bent upper side impact tube solution illegal, or at least very wide. Is that the intention? Would it not make more sense to brace a bend perpendicular to the plane of the bend to support rotation of the tube about it's ends?

T6.5.9 Rack attached to frame - Some designs specifically feature unsprung mounted steering gear (ie beam axles). Is the intention here to ban such concepts? Or simply to ensure attachments are suitably strong/rigid?

I.C.1.7.1 Restrictor, supercharger, throttle ONLY - I understand the reasons for this change for the turbo designs, but with bypass/recirculation valves etc banned, this now creates a big issue for any positive displacement supercharger, which are quite happy to operate in partial vacuum. Would a propriety internal relief or bypass valve be considered illegal?

I.C.4.6 IC max voltage. This (60VDC/25VAC) is well below what is seen in the typical motorcycle charging system. Is the intention these systems are no longer permitted and on board charging deleted, or are to modified to comply?

Pete

Westly

08-31-2014, 11:40 PM

Westly, the "general" rules has a restriction above 500mm, making the region above the tyre, but bellow 500mm allowed IMO.

My reading of T9.4.2 was it only applyes between front the front and rear axles? The diagrams also show no height restriction on the front wing.

T3.5.5 the angle of bend braces at less than 45 deg to the tubes bend plane will make the VERY common bent upper side impact tube solution illegal, or at least very wide. Is that the intention? Would it not make more sense to brace a bend perpendicular to the plane of the bend to support rotation of the tube about it's ends?

This sounds like it will affect many teams. My reading of this makes our chassis non-compliant unfortunately with a bent supported upper bar.

MCoach

09-01-2014, 12:23 AM

I agree with Andrew that rules are overly restrictive in relation to their implementation of ETC. In fact, when he brought that 10% note everywhere to me I knew exactly what it was referencing and think that it is completely unfounded to apply it to FSAE. For those who weren't aware of the blown diffuser era of F1, off throttle maps became a huge thing. The cars basically only closed the throttle on idle and purely controlled torque based off spark and fuel after that. Crazy aero ideas is why it was restricted there, not safety.

http://scarbsf1.com/blog1/2011/05/19/fia-ban-on-aggressive-off-throttle-engine-maps/

But they sounded awesome:
http://www.youtube.com/watch?v=BmGgvHflXgc

This isn't really relevant to FSAE and restrict us from doing more creative things with the power unit. The rules regarding the ETC plausibility seem more like something that would be required for competition just on ETC safety. If a mechanical throttle sticks open, that's cool just hit the kill switch and no one bats an eye. ETC is put on the car and it becomes restricted to the point that it operates almost exactly like a mechanical throttle with all the electrical wizz-bangs to make sure of it and kill the car if it ever recieves some proper massaging in that one special way....That's no fun. Snowmobile SAE rules are a fair implementation of ETC, I'd reference those.

It looks like the monocoque rules basically want you to build a whole two assemblies if you want to bring one to competition. Much more testing needs to be shown for all composite panels...watch out, they will make you crash test the whole car next and be subjected to the NVH subjective noise test. Maybe install some nicer carpets ;)

IC3.3 Maximum Sound Level
At idle the maximum permitted sound level is 100 dBC, fast weighting. At all other speeds the
maximum permitted sound level is 110 dBC, fast weighting.

Holy crap...let me go pull the muffers off all of my car. Someone must think we should be racing road sedans around these tracks. I think passing 110dBA was equivalent to 120dBC for us at competition and we were well over 114dBA at idle in some instances...

mech5496

09-01-2014, 02:23 AM

Much more testing needs to be shown for all composite panels...

This is not necesarilly bad...there are quite a few teams out there eager to build a monocoque but some times their choices are poor. Think about it, you cannot really fail on designing a spaceframe safetywise, the rules mandate a really large portion of the chassis anyway. Also the smaller WT allowed if tested are more than welcome.

I think we all agree that wording on the new aero rules is poor; too many words, schematics that contradict the wording and so on. But it is not only that. I did a quick readthrough, and here's an example:

"EV8.2.2 Accumulators must be removed from the car for charging..."
"EV8.3.7 ...In the case that the accumulator is charged outside of the vehicle..."

You kidding me? You just told me that accumulators MUST be charged outside of the car! Seriously, does anyone read the whole thing through before publishing?

apalrd

09-01-2014, 08:40 AM

I.C.1.7.1 Restrictor, supercharger, throttle ONLY - I understand the reasons for this change for the turbo designs, but with bypass/recirculation valves etc banned, this now creates a big issue for any positive displacement supercharger, which are quite happy to operate in partial vacuum. Would a propriety internal relief or bypass valve be considered illegal?

Some turbochargers (including the Garrett MGT1238Z which we acquired through the 'FSAE' sponsorship for our CSC clean snowmobile team) include an integral boss for a recirculation valve (Which is plastic).

A quick google image search found this picture of the turbo: http://www.turbosbytm.com/sites/default/files/styles/product_gallery_full/public/field/image/793996.gif?itok=FrM5YHLd The recircultion valve mounts to the hole next to the compressor inlet. Within that hole, the 'inner' port goes to the compressor outlet, and is surrounded by a port which connects to the compressor inlet. The recirculation valve moves in this space to recirculate. It's quite integral to the turbo, but the valve is removable as there are several designs (I have a pneumatic and direct-electrical pneumatically piloted one).

While a recirculation valve isn't as important to turbochargers, the question still comes up for integral recirculation valves. As they don't vent to atmosphere, and bypass the restrictor, is there anything wrong with integral recirc valves?

I agree as well, that for a positive displacement supercharger, throttle upstream of the supercharger is a requirement to keep power down without a bypass valve. Even with a bypass valve, most superchargers run a throttle before the supercharger

I.C.4.6 IC max voltage. This (60VDC/25VAC) is well below what is seen in the typical motorcycle charging system. Is the intention these systems are no longer permitted and on board charging deleted, or are to modified to comply?

This needs to be addressed by the rules committee. Would anyone like to submit a question for their evaluation?

IC3.3 Maximum Sound Level
At idle the maximum permitted sound level is 100 dBC, fast weighting. At all other speeds the
maximum permitted sound level is 110 dBC, fast weighting.

Holy crap...let me go pull the muffers off all of my car. Someone must think we should be racing road sedans around these tracks. I think passing 110dBA was equivalent to 120dBC for us at competition and we were well over 114dBA at idle in some instances...

Yes, we measured 116 dBA at idle at Michigan last year, due to the troubles we had balancing a high flow engine that wanted to rev high and a centrifugal clutch that required we keep the revs low at idle (we were sitting on the lean misfire limit, the noise was mostly due to popping).

We will likely need to at least double our muffler weight to comply with the new noise rules. This is an extremely unfair limit, especially to single-cylinder teams.

Mike, would you like to noise-test my car at warm up/light off idle and see if it passes the 100 dBC test?

apalrd

09-01-2014, 10:15 AM

would you like to noise-test my car at warm up/light off idle and see if it passes the 100 dBC test?

I used my team's sound level meter (the same meter we use to test our FSAE car for noise test) on my completely stock 2013 Fiat 500 Abarth and found that, already warm, the car hits 100 dBC fast weighting on the start flare, then drops to between 92 and 96 dBC depending on light-off (it cycles in a torque reserve for catalyst light off even at fully warm idle). This is at roughly 850 rpm.

If the engine was cold and stayed at the elevated idle for warmup and light off, it would have likely failed the FSAE idle sound test, at 1500rpm. Our FSAE car idles at 2600RPM, I don't know how we can be expected to be better than an OEM street muffler design on a racing car.

MCoach and I then tested his Sentra, with a modified header on a stock exhaust, he too failed the FSAE sound test, peaking the meter at 106+ dBC (for the 100 dBC range setting) at the start flare then decaying to 98 dBC at warm idle (800-900 rpm as well).

Edit:
We later tested both cars according to the noise standard (based on mean piston speed). The Abarth quieted down after it stopped retarding spark for catalyst light-off and passed the FSAE standard test at 5500rpm, but the Sentra failed (at 4500rpm) with a reading of 111 dBC.

After letting both cars sit for 4 hours, we tested again on, on elevated warmup idle. The Abarth failed with a 102 dBC elevated idle (~1500rpm) before settling down to the previously seen ~94 dBC normal idle. The Sentra failed the idle test when warm, at 106 dBC (at ~1100rpm) before settling down as well.

I'm honestly not sure how race cars are expected to be quieter than OEM production cars.

Mbirt

09-01-2014, 10:47 AM

I spent some time watching the dBC readings at Lincoln in 2013 and walked away thinking that something around 115 dBC would be appropriate to force the offending single-cylinder cars with lots of low-frequency content to address their problems while allowing the rest of the cars to carry on without incredible difficulty passing the noise test. Even 4-cylinder cars are going to have trouble passing at 110 dBC without rethinking their silencing for 2015. This is a big jump and some justification for the rule change would be nice.

Regarding the electronic throttle rules, it seems that the new rules strip away most of the advantages of running an electronic throttle.

"IC1.11.2 The electronic throttle must be automatically closed when power is removed from it."
"IC1.12.6 Each TPS must have a separate detachable connector that enables a check of these functions by unplugging it during Technical Inspection."
-Means no reliable, unmodified, off-the-shelf Bosch throttles allowed because they must be driven closed beyond the partially open limp-home position and have a common power supply for the two TPS signals.

APP rules likewise make it difficult to use a reliable, unmodified, off-the-shelf component like the pedal from the Polaris Ranger 900 XP.

These issues are minor, however, compared to the above-mentioned fundamental issue with the proposed electronic throttle control rules. If you cannot decouple throttle position from APP for engine control purposes, what's the point? I thought the point might be to use off-the-shelf components instead of custom components and a throttle cable, but that advantage is gone too.

MCoach

09-01-2014, 11:32 AM

May I suggest a really relevant noise test style? If we're building a "weekend autocross car" why don't we build to the SCCA noise limits since someone in the rules committee is feeling so inclined to change them.

http://www.scca.com:8090/documents/Solo_Rules/National_Sound_Measurements.pdf

stever95

09-01-2014, 12:23 PM

A couple things seem to have been cleaned up, and I'm pretty sure I found a rule or two written about because of our team..

However, overall I'm still bothered by how unclear and random many of the rules are. Pretty ridiculous for a competition of this magnitude.

mdavis

09-01-2014, 01:35 PM

I'm glad I'm not the only one upset about the new noise rules. I hope all of the single cylinder teams are using their time to design mufflers now, rather than getting the rest of the car done. OTS components will no longer pass noise without 2 mufflers in the system, so that will be fun. As MCoach suggested here, and I have suggested to FSAE individuals, the SCCA noise test makes so much more sense that it isn't funny. And yet, here we sit. Apparently FSAE rules committee cares more about "design challenges" than they do about the hearing of the on-track workers. If they cared about a certain situation, then they should test in that situation. Yet again, we see logic seems to have escaped the rules committee.

I still see no definition of "off-axis" impacts for IA's. This is something we got called out for at Lincoln 2013. I had a nice discussion with Mr. John Burford about this in the tech bay. He claimed that any off-axis impact would break our IA off and that we needed to add straps to retain the IA. I pointed out to him that while he may be right, there was no specified magnitude or direction of the off-axis impact that the IA needed to withstand in the rulebook, and therefore we were within the letter of the rules, and we didn't need to add the straps. I told him that if he wanted to call out teams on the off-axis loading condition, that there needed to be a standard test that was performed at the same time as other IA tests to prove that the IA was capable of handling such loading conditions. Apparently that conversation was forgotten when we rolled out of the tech area, or other things like header wrap and the noise levels of teams playing by the rules were deemed more important.

-Matt

apalrd

09-01-2014, 01:49 PM

I still see no definition of "off-axis" impacts for IA's. This is something we got called out for at Lincoln 2013. I had a nice discussion with Mr. John Burford about this in the tech bay. He claimed that any off-axis impact would break our IA off and that we needed to add straps to retain the IA. I pointed out to him that while he may be right, there was no specified magnitude or direction of the off-axis impact that the IA needed to withstand in the rulebook, and therefore we were within the letter of the rules, and we didn't need to add the straps. I told him that if he wanted to call out teams on the off-axis loading condition, that there needed to be a standard test that was performed at the same time as other IA tests to prove that the IA was capable of handling such loading conditions. Apparently that conversation was forgotten when we rolled out of the tech area, or other things like header wrap and the noise levels of teams playing by the rules were deemed more important.

We had an identical conversation with a tech inspector at 2014 Michigan. We too were eventually found to be compliant, by the letter of the rules and the testing definition.

apalrd

09-01-2014, 01:59 PM

I read over some other relevant competition rules regarding electronic throttle control. Here's the relevant ETC rules from Formula Hybrid (a US competition developed from the Formula SAE rules of the time, which has evolved separately over the last few years).

IC1.6.4 Electrical Accelerator Actuation
When electrical or electronic throttle actuation is used, the throttle actuation system must be of a fail-safe design to assure that any single failure in the mechanical or electrical components of the Accelerator actuation system will result in the engine returning to idle (IC engine) or having zero torque output (electric motor). See also: EV2.2.

Teams are strongly encouraged to use commercially available electrical Accelerator actuation systems.

The methodology used to ensure fail-safe operation must be included as a required appendix to the Design Report. See S4.2.1. A printed copy must be handed to inspectors at the beginning of Electrical Tech Inspection.

In fact, the length of the rules governing electronic throttle control are shorter (fewer lines) than the rules governing mechanical throttle controls, which are concerned with the cables jamming, or melting on the exhaust (which is not a concern with ETC throttles). I don't know enough more about Formula Hybrid to know of any team experiences with these rules.

Next, I bring the relevant rules from the SAE CSC (Clean Snowmobile Challenge):

4.2.6 Throttle Requirements
An adequate return spring on the throttle is required. The throttle must remain on the right side. The throttle will be operated with a direct mechanical operated thumb mechanism located on the handlebar to the rear of the machine (no twist grips). Fly-by-wire throttle systems are allowed.

The CSC rules also later specify a check of the throttle return spring during dynamic tech inspection (a process where a tech inspector rides the snowmobile on a small closed course to verify the vehicle response is acceptable for CSC, that it meets the minimum required speed, and that it shuts off as expected via the kill switch). In fact, Diesel snowmobiles are not required to run a throttle at all, and must simply retain the 'throttle' input from the driver. Several teams successfully have run ETC systems with great results, including the 2013 and 2014 competition winning teams. Several teams have also caught fire over the years, and there have been no ETC-safety issues ever (as long as I have been competing).

Next, I bring the Supermileage rules relevant:

B5.6.7 Throttle Control by Wire
B5.7.1 The engine throttle can be controlled electrically. Provided at least one (1) of the following conditions is met:
(1) The system will immediately return to a closed throttle condition if any part of the system fails.
(2)The kill switch circuit must leave the engine inoperable if any portion of the kill circuit fails. Thisincludes wire breakage and electrical short to chassis.
Again, they are letting teams determine their own safety and reliability strategy.

mdavis

09-01-2014, 06:09 PM

We had an identical conversation with a tech inspector at 2014 Michigan. We too were eventually found to be compliant, by the letter of the rules and the testing definition.

That's what made it so much more fun. We had no issues with the same IA at MIS 2013. Tech in Lincoln 2013 was really stressful for us, when it really shouldn't have been. We got called on a lot of things that weren't out of the letter of the rule, but were rather judgement calls from the inspectors. The biggest was our seat belts, where because the spec on the belts didn't match the one in the rulebook, the inspector wasn't going to let us through, even after we showed him the spec in the rules that basically says "any belts that carry a given designation meet this standard". I'm sure I lost a few years off my life trying to call HMS, go find the tech inspector (who left the event, right after we got done in the tech bay the first time through), try to find the Chief tech inspector, call HMS back, lather, rinse, repeat. So when the IA was called into question (yet another thing where we met the letter of the rules, but apparently not the inspector's interpretation of things, or actually in this case, another individual at the competition, rather than our actual tech inspector), it was highly annoying and just added more unnecessary stress.

-Matt

John_Burford

09-01-2014, 06:47 PM

Mcoach

The SCCA noise measurement approach has been tried in Formula SAE with very bad results.

John Burford

Loz

09-01-2014, 07:07 PM

Clarity and ambiguity are out the window with the hugely subjective aerodynamic structural requirements rule.

The undefined, completely subjective and ambiguous components are in bold.

T9.7.1 All aerodynamic devices must be designed such that the mounting system provides adequate rigidity in the static condition and such that the aerodynamic devices do not oscillate or move excessively when the vehicle is moving. In Technical Inspection this will be checked by pushing on the aerodynamic devices in any direction and at any point.

Still no definition of what constitutes an aerodynamic device. Does this mean the rule applies to any external wetted surface?

It also includes a very vague stiffness requirement for "adequate rigidity" when static? "Adequate rigidity" is vague enough without it then having to be subjectively measured...

The undefined aerodynamic devices must not oscillate or move "excessively when the vehicle is moving". No clarity about what excessive movement is nor under what dynamic conditions it pertains to. Presumably measured again by eyeball.

They will check this by "pushing" on the undefined aerodynamic device in any direction at any point. Effectively they can push on any part of the vehicle wetted surface (structural or otherwise) and if they think it moves too much then you have problems.

Then it seems they seek to clarify the rule but do nothing of the sort.

T9.7.1 (continued) NOTE: The following should be seen as guidance as to how this rule will be applied but actual conformance will be up to technical inspectors at the respective competitions. The overall aim is to reduce the likelihood of wings detaching from cars whilst they are competing.

A rule that is vague, completely unclear and is measured by a subjective yardstick is written and stipulated to be "guidance" as to how the rule will be applied? It actually speaks very little about how the rule will be applied and certainly does not provide any guidance.

Then finally the slightest bit of an engineering requirement in the rule as note 1, yet it still remains ambiguous, subjective, unrepeatable and lacks any way of applying it consistently within a single competition let alone throughout all competitions.

T9.7.1 NOTE (continued)
1. If any deflection is significant, then a force of approximately 200N can be applied and the resulting deflection should not be more than 25mm and any permanent deflection less than 5mm.

One more use of a very subjective measure and another which in spite of them including a numerical figure (200N), is still only approximately defined. How do they intend on actually applying this approximate 200N load? A scrutineer with a well calibrated elbow?

It goes further to say that resulting deflection cant be more than 25 mm. Between which two points is this 25 mm being measured and how do they plan on actually measuring this movement of 25 mm in free space in any possible direction? Will they bring a CMM arm to each event? Presumably it will again be a subjective assessment.

If wings detaching themselves are such a big problem why not just mandate a tether line (of specified material) tying all wings back to the primary structure.

kkung

09-01-2014, 07:59 PM

MCoach

09-01-2014, 08:44 PM

John,

Could you elaborate on why the implementation did not go as expected? Feedback and understanding as to why the rules have been structured and implemented are as well as any history attached gives significant insight to the teams.

John_Burford

09-01-2014, 09:10 PM

Sound is cumulative. Depending on how close another car is to your car, you may violate the sound threshold. This also causes complication as to which car violated sound. After a few years of this approach, steady-state testing was adopted. Teams were very happy to go away from the SCCA approach. Also under the SCCA approach, many teams would not know they were violating sound until endurance.

John Burford

MCoach

09-01-2014, 09:26 PM

I think if more leeway was given on sound for an event like accel, have the teams run accel with the microphone set up nearby and if they fail or get close (similar to the SCCA rules) then they are warned or told to fix it. Any runs that are made outside the sound threshold are either dropped or held hostage until a fix is made. I've had this work for a much more amateur and more rule breaking prone class where I held fast lap times for qualifying hostage until either an item was fixed or a penalty was accepted.

We don't have to wait until the endurance to test teams. There are plenty of opportunities to test beforehand. I'm open to much more discussion of the rules topics at hand.

Thank you.

apalrd

09-01-2014, 09:31 PM

I found, for your viewing pleasure, the relevant US regulations governing electronic throttle control systems. Here is a link to NHTSA FMVSS 124 (NHTSA is National Highway Traffic Safety Administration, FMVSS is Federal Motor Vehicle Safety Standard). FNVSS 124 governs 'accelerator control systems': http://www.gpo.gov/fdsys/pkg/CFR-2012-title49-vol6/xml/CFR-2012-title49-vol6-sec571-124.xml

The FMVSS requires two things:

-That there are two energy sources to return the throttle to an idle position. Normally, the first energy source is the throttle motor itself, and the second is the failsafe return spring. For mechanical throttle systems, two return springs are required.
-That the throttle return to idle position (which is allowed to vary based on temperature, emissions calibration, etc.) when the driver LIFTS THEIR FOOT FROM THE THROTTLE PEDAL, or there is a failure of the control system. There is no verbiage to indicate any dependency on the brake in this case, at all.

In fact, NHTSA discussed a 'brake-pedal override' feature to be added to FMVSS 124, following the toyota unintended acceleration scandals of a few years ago. If anyone feels like reading it, here's the link to the proposal: www.nhtsa.gov/staticfiles/rulemaking/pdf/FMVSS_124_BTO_NPRM_Final.pdf (It's long, I suggest not reading it). Here are a few excerpts:

The BTO [Brake Throttle Override] system may check conditions such as vehicle speed, engine revolutions per minute (RPM), brake pedal travel, and pedal sequence (i.e., whether the brake was pressed first and then the gas pedal, or vice versa) to determine if the driver’s intention is to stop the vehicle. Based on these conditions, the BTO system may determine that the combined brake and gas pedal inputs are actually intentional

We believe there is no particular safety issue in these situations, and in fact this type of “two-footed” driving capability can be desirable and may be in widespread use.

The current language of the test procedure in FMVSS No. 124 is expressed in terms of the return of an observable moving part, i.e., the throttle plate, to a closed or nearly closed position. It does not prescribe other types of vehicle fail-safe responses besides throttle closure. This neglects the variety of ways in which powertrain output in a vehicle with a modern throttle control system can be reduced to an acceptably benign level, e.g., spark adjustment, even though the throttle plate may be at a non-idle position.

NHTSA does not believe the intent of the Standard should be construed as merely setting a limitation on throttle position. Instead, it is evident that the fundamental safety purpose of the Standard is to prevent a vehicle's powertrain from creating excessive driving force when there is no input to the accelerator pedal. There would be no safety reason whatsoever to require the throttle to close if that did not limit vehicle propulsion.

Even if it is well established that FMVSS 124 does apply to ETC systems, regulating ETC systems by drawing analogies to mechanical systems has undesirable outcomes.

Fuel injection and ignition timing are among factors that can be varied without any change in throttle position.

Modern engines routinely have variable valve lift and/or timing control. In at least one recent engine design, the level of valve control is great enough that the throttle plate no longer throttles the engine during at least part of the engine’s operating range. Instead, air intake is throttled to a large extent by the intake valves themselves while the throttle plate stays in an open position. In such a design, requiring "return of the throttle to the idle position" would be design restrictive without any safety justification.

Finally, here's a video of a rally driver (with a highly turbocharged engine) which clearly shows that he uses two pedals (in some cases, it appears three) at the same time. Additional airflow is required to build boost, and honoring a legitimate driver demand is not a safety issue. https://www.youtube.com/watch?v=wdy8CG09rSU

JulianH

09-02-2014, 03:48 AM

Ok, it seems that the ETC rules are a bit too extreme... Is Kettering University the only team that has an issue with that (the only team that planned to run it?!) or are the others just silent?

In my experience, Michael and Andrew, complaining about it in this forum does not change anything. You should take it up to the rules committee. When FSG announced some serious Aero restrictions for 2014, the guys from Monash wrote a nice document where they explained why the rules are too strict - not purposeful.

Maybe your team - with the experience of CSC - could try a comparable approach. To be honest, I still think the Germans are much better to talk to compared to the US responsibles, so don't know if this works, but it's worth a shot...

Kevin,
you proposed a delay of the rules for 2016 - do you still think this is necessary? I am sadly not able to fully understand the impact of the changes so don't know if the teams that already started designing their car for Michigan have an issue. If Curtin wants to go to Europe 2015, do they need more changes besides a different aero package?

NickFavazzo

09-02-2014, 03:50 AM

John, Is there a reason or has it been done before, that we don't use drive by testing (such as on the run up to the brake test or on an accel length road). As I understand this is how noise compliance is tested on motorcycles at most racetracks in australia. Motorcycle racing GCR specify testing to be done towards the end of a straight under full throttle.

I don't know of anywhere where noise is measured with a static vehicle.

Also in regards to the SCCA rule style testing (which sounds similar to the motorcycle noise testing method) why not do the testing on a longer run immediately after brake test?

John_Burford

09-02-2014, 04:29 AM

Westly

09-02-2014, 05:32 AM

If Curtin wants to go to Europe 2015, do they need more changes besides a different aero package?

Hi Julian,

Based on my reading of rule T3.5.5 "The support tube must have the same diameter and thickness as the bent tube, terminate at a node of the chassis, and be angled no more than 45 degrees from the plane of the bent tube." our upper side impact bar would not be rules legal. Although we potentially get around this with stressed panels and then structural equivalency.

A few pictures of our 2013 chassis are here, our 2014 side impact is similar. https://www.facebook.com/media/set/?set=a.573768912656494.1073741826.213826348650754&type=3

alexlewis

09-02-2014, 06:00 AM

Reading through the new monocoque rules for our first metallic monocoque in 2015, this new section really stumps me:

T4.5.4 EV CARS ONLY
In addition a firewall must separate the driver compartment from all tractive system components.
NOTE: this includes any HV wiring.
The tractive system firewall must be composed of two layers:
a. One layer, facing the tractive system side, must be made of aluminum with a thickness
between 0.5 and 0.7 mm. This part of the tractive system firewall must be grounded according
to FSAE Rule EV4.3.
b. The second layer, facing the driver, must be made of an electrically insulating material. The
material used for the second layer must meet UL94-V0, FAR25 or equivalent. The second
layer must not be made of CFRP.

Is a 0.8mm aluminium skin illegal? And does only the firewall have to be coated with rubber or everything that the driver touches? Obviously they want to electrically isolate the driver in the case of the tractive system energising the chassis but surely a completely conductive box is going to do a better job then a layer of rubber on a part the driver is never going to touch since the seat will separate them from the firewall....

jd74914

09-02-2014, 07:09 AM

Ok, it seems that the ETC rules are a bit too extreme... Is Kettering University the only team that has an issue with that (the only team that planned to run it?!) or are the others just silent?

I think Kettering just has the most familiarity/design maturity due to CSC. I agree with the Kettering appraisal from my current understanding of ETC. As far as I can read, the rules implementation of ETC literally is just replacing a conventional cable with ton of sensors, wires, and a motor without presenting much possibility to reducing pumping losses due to throttling which is really the biggest benefit to ETC. Right now the ETC rules really only let you decouple pedal movement from butterfly movement (you could more-or-less do this with a mechanical cam) and add a whole ton of failure modes into the package which are not present with cable throttle bodies. My team is not ready to implement ETC, but given the current rules I believe we would think twice about doing it from an FMEA sense alone as there really aren't many benefits to outweigh the increase in failure modes or huge amount of design time.

Kevin Hayward

09-02-2014, 07:11 AM

Julian,

My reasons for proposing the delay were stated as:

- Allowing teams to have plenty of time to adjust to large concept changes
- Allowing time for feedback and development of clearly worded rules with objective scrutineering procedures
- Avoiding situations where teams are not able to travel due to cars becoming illegal, with unreasonable changes required to make them legal in a short time frame

Most of the focus of discussion was on the first point, but I feel much more strongly about the last point. The team I am faculty advisor for was unable to travel to the UK in 2013 because of a minor change to the chassis rules that was not announced prior to the official rules release.

In this set of rules we have all three problems well and truly covered.

These rules have significant conceptual effects

There are quite a few sections which are quite subjective. Hopefully there will be a lot more clarification on the scrutineering procedures in the coming months.

Finally there are lots of small changes that affect the main structure of the car. A lot more monocoque testing, increased restrictions on spaceframes as well as a lot more details about bolted joints. In amongst that there is plenty that could invalidate a car built to the current rules structurally. A grandfathering clause would be really useful for these cases, otherwise teams may have to make fundamental changes to chassis systems. Something that I think would stop affected teams being able to travel. Of course these a preventable by much earlier rules releases.

I think a good argument could be made that expecting smaller wings (or other performance hit) is not too much to ask of traveling teams, but full tear-downs with potentially large structural modifications is going too far.

Without going into details (a lot of points in this rules release) yes I do think a delay would have been the wise choice. What may be helpful now is to look to an earlier release in following years as being a standard. In the discussion we had on the other thread there wasn't any opposition to the idea that rules releases could be made earlier.

...

O̶f̶ ̶p̶a̶r̶t̶i̶c̶u̶l̶a̶r̶ ̶i̶n̶t̶e̶r̶e̶s̶t̶ ̶t̶o̶ ̶m̶e̶ ̶i̶s̶ ̶t̶h̶e̶ ̶c̶h̶a̶n̶g̶e̶d̶ ̶w̶o̶r̶d̶i̶n̶g̶ ̶a̶b̶o̶u̶t̶ ̶t̶i̶r̶e̶ ̶t̶r̶e̶a̶t̶m̶e̶n̶t̶.̶ ̶ ̶I̶t̶ ̶a̶p̶p̶e̶a̶r̶s̶ ̶t̶h̶a̶t̶ ̶w̶h̶a̶t̶ ̶w̶a̶s̶ ̶o̶n̶c̶e̶ ̶b̶a̶n̶n̶e̶d̶ ̶o̶u̶t̶r̶i̶g̶h̶t̶,̶ ̶a̶p̶p̶e̶a̶r̶s̶ ̶t̶o̶ ̶b̶e̶ ̶e̶n̶c̶o̶u̶r̶a̶g̶e̶d̶ ̶b̶y̶ ̶w̶a̶y̶ ̶t̶h̶e̶ ̶r̶u̶l̶e̶s̶ ̶a̶r̶e̶ ̶w̶r̶i̶t̶t̶e̶n̶.̶ ̶ ̶T̶h̶i̶s̶ ̶i̶m̶p̶l̶i̶e̶s̶ ̶t̶o̶ ̶m̶e̶ ̶a̶ ̶p̶e̶r̶c̶e̶p̶t̶i̶o̶n̶ ̶t̶h̶a̶t̶ ̶t̶e̶a̶m̶s̶ ̶h̶a̶v̶e̶ ̶b̶e̶e̶n̶ ̶t̶i̶r̶e̶ ̶t̶r̶e̶a̶t̶i̶n̶g̶ ̶a̶n̶d̶ ̶i̶t̶ ̶i̶s̶ ̶t̶o̶o̶ ̶d̶i̶f̶f̶i̶c̶u̶l̶t̶ ̶t̶o̶ ̶a̶s̶s̶e̶s̶s̶ ̶a̶t̶ ̶c̶o̶m̶p̶s̶.̶ ̶ ̶I̶ ̶w̶o̶n̶d̶e̶r̶ ̶w̶h̶a̶t̶ ̶p̶r̶o̶d̶u̶c̶t̶s̶ ̶t̶e̶a̶m̶s̶ ̶h̶a̶v̶e̶ ̶b̶e̶e̶n̶ ̶u̶s̶i̶n̶g̶.̶ ̶ ̶I̶ ̶w̶o̶u̶l̶d̶ ̶i̶m̶a̶g̶i̶n̶e̶ ̶t̶h̶a̶t̶ ̶o̶u̶r̶ ̶t̶e̶a̶m̶ ̶w̶i̶l̶l̶ ̶h̶a̶v̶e̶ ̶t̶o̶ ̶a̶l̶l̶o̶c̶a̶t̶e̶ ̶r̶e̶s̶o̶u̶r̶c̶e̶s̶ ̶t̶o̶ ̶t̶i̶r̶e̶ ̶t̶r̶e̶a̶t̶m̶e̶n̶t̶ ̶n̶o̶w̶.̶

O̶n̶ ̶o̶n̶e̶ ̶h̶a̶n̶d̶ ̶t̶h̶e̶r̶e̶ ̶i̶s̶ ̶a̶ ̶p̶u̶s̶h̶ ̶t̶o̶ ̶h̶a̶v̶e̶ ̶i̶n̶c̶r̶e̶a̶s̶e̶d̶ ̶c̶o̶n̶t̶r̶o̶l̶ ̶o̶v̶e̶r̶ ̶p̶r̶o̶c̶e̶d̶u̶r̶e̶s̶ ̶t̶e̶a̶m̶s̶ ̶p̶e̶r̶f̶o̶r̶m̶ ̶o̶u̶t̶s̶i̶d̶e̶ ̶o̶f̶ ̶t̶h̶e̶ ̶c̶o̶m̶p̶e̶t̶i̶t̶i̶o̶n̶ ̶(̶i̶.̶e̶.̶ ̶c̶o̶m̶p̶s̶ ̶p̶u̶n̶i̶s̶h̶i̶n̶g̶ ̶t̶e̶a̶m̶s̶ ̶f̶o̶r̶ ̶u̶s̶i̶n̶g̶ ̶t̶h̶e̶i̶r̶ ̶c̶a̶r̶s̶ ̶f̶o̶r̶ ̶p̶u̶r̶p̶o̶s̶e̶s̶ ̶n̶o̶t̶ ̶a̶p̶p̶r̶o̶v̶e̶d̶ ̶o̶f̶ ̶b̶y̶ ̶t̶h̶e̶ ̶o̶r̶g̶a̶n̶i̶s̶e̶r̶s̶)̶,̶ ̶a̶n̶d̶ ̶h̶e̶r̶e̶ ̶w̶e̶ ̶h̶a̶v̶e̶ ̶i̶m̶p̶l̶i̶c̶i̶t̶ ̶a̶p̶p̶r̶o̶v̶a̶l̶ ̶o̶f̶ ̶p̶l̶a̶y̶i̶n̶g̶ ̶a̶r̶o̶u̶n̶d̶ ̶w̶i̶t̶h̶ ̶s̶o̶m̶e̶ ̶p̶o̶t̶e̶n̶t̶i̶a̶l̶l̶y̶ ̶v̶e̶r̶y̶ ̶n̶a̶s̶t̶y̶ ̶c̶h̶e̶m̶i̶c̶a̶l̶s̶.̶

Apart from fairly consistently advocating an earlier release of the rules my other favorite hobby horse is to introduce homolgated tyres to the competition. Tyres supplied at the comp for running, by suppliers that can supply a minimum number of approved tyres (i.e. no special one-off tyres). Tyres have always been a considerable expense and waste. Who cares about saving 1-2 litres of fuel when you throw out tyres after 22km? Now we are likely to see another tyres arms race, but with all sorts of treatments as well as the custom tyres starting to appear.

Obviously an earlier release (or at least an early draft release) would enable a decent period of feedback and explanation to occur. Maybe we can start a push to have the 2016 rules released somewhere between feb and may in 2015.

Kev

JulianH

09-02-2014, 07:40 AM

Thanks for your answer Kevin.
It's always difficult to be "the old car in a new set of rules". I think the "Monash way" to skip every second year and have a car built to the first year of the two year cycle is the better choice. So for Australian teams to be in Europe in even years. I still would love to see all of you guys in Europe every year but I'm sure that the new rules are only one fraction of the issue here. Budget is probably more difficult...

About the tires:
When I was part of the staff at FSA this year, there was one team that obviously soaked their tires in some grip enhancers (when they opened the tire protectors the tires seemed basically "wet"... The scrutineers saw that but the reaction was sooo quickly: "Yes, but we did it before static judging so it's ok". And that was it...

I think it is ok to use tire softeners or what ever because otherwise we had to ban customized tires too (Delft, Eindhoven and Darmstadt are basically able to bring tires "softened" at the competition...).

But what I don't like is that this excessive use of tire softener reduces the life span of the tires and therefore leads to a budget-issue.

In my opinion a new rule should be introduced that only one set of tires is allowed to be used at the dynamic events. Teams can do brake test or testing on an old set but if they enter a dynamic event, they can only run this marked set.
If they think they can run an endurance with softened tires, ok.

But, I think using "suuuper softened" tires for Accel / Skidpad, "medium softened" tires for AutoX and "mildly softened" tires for Endurance is an unfair advantage for the "rich teams". Tires are expensive...

NickFavazzo

09-02-2014, 07:48 AM

Nick

The brake check and acceleration run do not test enough of a range of engine events. Many of the sound violations come from off throttle events including backfires that show up while running the endurance event. Putting a meter out on track and handing penalties for sound violations caused frustration for students and organizers. You do not want that simulation to return.

John Burford

If on track violations are enough for ADR and other non-FSAE motorsport organisations then why should FSAE be different, competitions are often run at motorsport venues, surely fitting to the tracks existing noise restrictions is sufficient.

I wasn't really suggesting having a meter permanently on track though, but rather a chance for drive by noise to be tested (similar to the ADR test procedure).

Kev, Big fan of the homologated tyres idea or at least a homologated list with manufacturers guaranteeing the availability of sufficient tyres. Introduce a tyre war...

Dylan Edmiston

09-02-2014, 08:19 AM

Ok, it seems that the ETC rules are a bit too extreme... Is Kettering University the only team that has an issue with that (the only team that planned to run it?!) or are the others just silent?

I'm silently busy with other things. But I agree, they are too extreme and there are some confusing parts in there that I need clarification on with the rules committee.

Yannick

09-02-2014, 09:24 AM

I will also comment on the tires:

In my opinion spec tires are not a good idea. We have seen that different tire size can work well in different conditions. Let the teams figure out what is best for them. I think this diversity is important to FS.

I agree however that there is a trend to play a lot with the tires to get more performance out of them. This will lead to (even) more money being spent on tires, which is debatable if it is sustainable for the educational aspect (a lot of this knowledge is probably only useful for hill climbing). I don't see a problem with teams using tire softeners per se, it was allowed in my understanding in previous years. But know the extent of what teams are trying to do with tire softeners is getting out of bounds in my opinion.

To come back to the example, at FSA, there were 3 teams that for sure used a lot of the stuff. As Julian said, some of the tires were wet after the tire protectors were taken away (definitely not water). Also after doing some suspension checks before endurance (and thus touching the tires) my hands were full of rubber.

The problem is more, as Julian pointed out, that teams have started to have different sets for Acc., Skidpad, AutoX and Endurance. This is, again in my understanding, not allowed. While it originally was the same compound, they are not anymore due to the treatment. A similar / same issue is possible with a team that has self made tires. How do you know if they have the same compound on all dry tires for example?

I think the suggestion by Julian makes a lot of sense. Like this learning about tires and tire modification is not prohibited but there are some bounds given.
Another way of handling this is how it is already done at FSG (for custom tires only), where you have to present all tires you have with you. Then the officials selects random sets of four which are marked accordingly.

Cheers
Yannick

apalrd

09-02-2014, 10:08 AM

In my experience, Michael and Andrew, complaining about it in this forum does not change anything. You should take it up to the rules committee. When FSG announced some serious Aero restrictions for 2014, the guys from Monash wrote a nice document where they explained why the rules are too strict - not purposeful.

How can I contact the rules committee for Formula SAE in the US?

The Formula Student Germany website clearly lists the members of their board and rules committee, and an email to contact all of them by. In fact, their Contact page directs me to their Officials page 'for specific issues', and suggests emailing the relevant people directly.

For Formula SAE, the only page I see is http://students.sae.org/cds/formulaseries/contact.htm which lists the names of the manager of each program, and a single email to direct all inquiries related to CDS. Surely this can't be the place to email the rules committee specifically?

JulianH

09-02-2014, 12:50 PM

I got an answer from Kaley (kzundel@sae.org) about the ridiculous 300V limit. I think she forwarded the mail and came back to me.

It took only a week, sadly my reply 14 minutes later (August 19th, 2013) was never answered.

Another possibility would to contact Tobias Michaels (michaels@Formulastudent.de) from FSG. He is responsible for the electric rules (maybe he even was part of the ETC rules implementation...). He is a great guy and forwards your letter to any responsible from the states.

DMuusers

09-02-2014, 01:12 PM

So I'll add in my say on tires:

- On the topic of self-designed tires and different compounds: First I want to say that we (TU Delft) haven't competed on different compounds at any competition that we attended, although I heard there were some rumours flying around. It's understandable that these rumours are there, since you can't really see if the acceleration tires are the same compound as the scrutineering or endurance tires. During scrutineering we also handed in a signed document by our sponsor stating that all slicks were the same compound aswell as all the wets. I also think people underestimate how hard it actually is to create a compound that is currently better than the Hoosiers, although it's not impossible. However, I don't think teams (custom tires or not) should be prohibited to use more than one set. Mainly because anything can happen during competition to the tires rendering them useless, for example a puncture. It would be extremely demotivating, and I think also not in spirit of fair and equal competition (though that's debatable).

- On the topic of tire softeners: using tire softener actively alters the compound. Since the rules state all slicks should have the same compound, tire softeners are (in my opinion) banned since you cannot show that all tires are the same compound after using it. Besides, it can be extremely dangerous since you're basically degrading the molecular bonds of the tires, which can cause them to rip apart.

- On topic of scrutineering the tires: in FSG they tell the teams with custom tires to bring them all so they can decide which 4 are a set (in case of multiple tires). I think this is a great solution and should also be applied to all teams. This makes sure that no team uses at least different amounts of tire softener. The downside is that heat cycle testing and such become obsolete, however I feel that with the Hoosiers at least the fewer heat cycles the better.

JulianH

09-02-2014, 02:15 PM

Daniel,

I heard the rumours in Germany as well. Someone of your team said that you have been testing different compounds, so it's not a long thought from "they have different compounds" to "they'll use different compounds". I don't insinuate that Eindhoven or Delft really did that, but you understand that this is something obvious to think... I think the German solution: "We decide which tire is used when" is just perfect to end such rumours.

About multiple sets:
I still think that it is a good idea to limit the number of tires to one set. In case of a puncture or something strange happening, of course teams can rescrutineer a spare tire...
Why do teams need more than one set?
If we leave out the Endurance, you don't drive more than 3-4km at an event. I think 22+4km should be an easy task for a tire. Even if you customize it.

I know that it is a large advantage for a team like yours to really develop a tire just for 22km instead of like 100km for a regular Hoosier tire. But you still can make it work with a bit less advantage...

If you ban tire softeners or what ever chemicals because they are "dangerous", one would have to ban student developed tires as well, because you also can't assure that they did not play with such stuff. Not every team has a big partner like Delft/Eindhoven/Darmstadt.. maybe one day there will be a team coming to competition with KARACING or TUFAST tires.. we don't know.

The team with soaked tires is running those since 2010 at least and there was never a tire rupture (in fact I never seen such a damage at an FS event)... in the last 5 years I saw at least 10 flying wheels and 5 burning cars which are both probably more dangerous than a tire rupture..

DMuusers

09-02-2014, 04:03 PM

Hi Julian,

we tested different compounds yes. I actually have written 2 reports of our compound tests (iteration 1 and 2) and have discussed this during engineering design at all competitions we attended. At the end though we decided on one compound to go on our slicks. We actually don't have any tires with different compounds lying around for the DUT14 because they were simply never made (I should know, I designed them).

I also agree that maybe a limit of 2 or 3 sets seems very reasonable (1 set acc, skid, autox, 1 set endu. or 1 set acc, skid, 1 set autox, 1 set endu.) and then have the scrutineers pick the sets for which event. Right now one set of our tires should last an entire competition quite easily, but if something is wrong with one of them, it could be that we (or if some other team had a puncture or whatever with this rule) wouldn't be able to compete properly.

Another thing about the development of compounds. It's not something that you just 'do'. I don't think any team will be able to do this without a significant and highly specialized sponsor. There's a lot of reasons highly trained specialists design these compounds so therefore I'm not afraid that a team will make their own tire without a sponsor. You can always add a rule that the tires must be produced by an official tire company if you really think students can do this on their own.

How do you know that teams that used tire softeners have never had a rupture? It's something most teams wouldn't like to share on facebook anyway ;)

apalrd

09-02-2014, 04:11 PM

I got an answer from Kaley (kzundel@sae.org) about the ridiculous 300V limit. I think she forwarded the mail and came back to me.

I submitted an inquiry to the rules committee via Kaley. Hopefully the RC clears up the torque vs throttle rules, as well as a few others from the ETC section.

On a slightly related note, MCoach and I are also putting together an analysis of the noise output of stock production cars, to submit to the RC regarding the new 100 dBC idle rule. As it is, we have already found 2 cars which fail during warmup-idle. This is an issue which affects all teams, and I know we'll have quite a challenge meeting the 100 dBC idle with our muffler weight target on our single cylinder engine.

Kevin Hayward

09-02-2014, 06:02 PM

Yannick,

Please note the suggestion was for homologated tyres rather than spec. This would stop custom tyres, but everything else would be okay.

I completely agree with the 4 tyres per comp, maybe with up to 6 allowed to account for a puncture(s) They can be randomly numbered by a scrutineer such that the first four must be used until damage occurs.

...

I am not sure that custom tyres are legal as per the current rules, and am conflicted by their use. On one hand it is great to see teams going that far, and engaging industry. However it seems pretty clear that without external specialized knowledge that it is not possible to design and construct the tyres. To quote Daniel:

"I don't think any team will be able to do this without a significant and highly specialized sponsor. There's a lot of reasons highly trained specialists design these compounds so therefore I'm not afraid that a team will make their own tire without a sponsor."

This looks like a violation of A6.1 and A6.3. For other difficult design areas (such as custom engine) it has been proven to be in the capability of a team to do the complete design and fabrication inhouse.

I think if such an engagement was to lead to a FSAE tyre available to all who ask it would be a different matter, as it is students assisting in the development of a commercially available product. I would say this occurred with Goodyear previously, but obviously with almost no input on design (more on feedback and testing). In this scenario you can have students actively involved in tyre design and development, but without a violation of the rules. The teams involved in the development would still have sole access to the information they developed if they wished.

...

This is the interesting thing about new rules. You think that the announced changes will have the biggest effect (i.e. big aero changes), but I would suggest that by making teams aware of tyre treatments and putting bounds on their use will have a much bigger impact over the full field. Any serious team should be considering what to do. Previous rules have banned it outright, maybe it has been seen in later rules as a matter of interpretation, but now there are clear guidelines of when tyre treatment is okay.

Kev

Jan_Dressler

09-02-2014, 06:33 PM

Kevin Hayward

09-02-2014, 08:00 PM

I was just browsing through the old rules (much easier because they are much shorter). I had missed the obvious:

"No traction enhancers may be applied to the tires after the static judging has begun."

Which clearly makes traction enhancers okay to use. It was my old and incorrect interpretation that led to me thinking otherwise. Please disregard my comments about this being a change. It also represents an increase in safety in the just released rules.

Apologies,

Kev

AxelRipper

09-02-2014, 10:59 PM

Kev, at least they're discouraged on site now (which they really always have been unwritten-like). Ever been to a dirt kart track? All that is is tire prep. Learning what combination of chemicals to rub on the tires and how long to take the torch to them to get them right. There's definitely an art, and if someone were to have individual sets of tires for accel and skidpad they could probably pickup a tenth or two, with the same compound (we had a good 40 Shore A swing between 3 different sets of the same compound of tire).

Other than the bafflingly complicated ETC rules and sound limits that have already been discussed, the only one that really confused me was the 45 degree tube bracing rule. Could someone diagram that? It really doesn't make any sense. Which plane are we talking here that it can't be out of skew with?

John_Burford

09-03-2014, 12:32 AM

Example of why brace must at an angled no more than 45 degrees from the plane of the bent tube.

Kevin Hayward

09-03-2014, 01:22 AM

Out of interest I thought I would show the page count for some of the rules releases. This is from 2001 (the first year I competed as a student). I am missing 2003 and 2005. By the way it might be worth creating a place to access the history of FSAE (i.e. previous rules) to see how it has evolved. Here is an image of the page count vs. year:

http://i.imgur.com/Pa1yg9i.jpg

2001 - 86
2002 - 93
2004 - 104
2006 - 125
2007 - 124
2008 - 118
2009 - 105
2010 - 108
2011 - 130 (Alternative frame rules added)
2012 - 131
2013 - 163 (EV rules added to current rule set)
2014 - 163
2015 - 176

By the way this is my first image post since joining here in 2002. Even with a com sci degree it takes a little while to get around to some things :)

Kev

DMuusers

09-03-2014, 01:42 AM

Hey Kev,

I'll quote first, so it's easier to explain:

"This looks like a violation of A6.1 and A6.3. For other difficult design areas (such as custom engine) it has been proven to be in the capability of a team to do the complete design and fabrication inhouse."

I don't think custom tires are a violation of this rule. Since its intent is teams basically buying their whole car. That's not what happens with custom tire design (at least within our partnership with Apollo or Eindhovens)(I don't know the details of Darmstadt, so I can't speak for them). It's not like we go to our sponsor and say we want a tire. We actually design everything about it, they just deliver the raw material and production process. Just like someone designing a titanium upright or a printed steering wheel. If you can't have those production processes sponsord, a lot of teams wouldn't build the cars they are building now. No validation on aerodynamics in a windtunnel for example or stock bought ECU's.

You should see a tire not so much as one part, but an assembly of a lot of different parts, with each its own function. If you've never seen the actual internals of a tire I suggest you cut open an old one. The tread compound is only a small part of the tire itself ;)

Kevin Hayward

09-03-2014, 02:24 AM

Daniel,

I have found these clauses very poorly written. I don't think the intent is for the whole car at all. I have heard a rules committee member state about these sort of items is that they should be available for all, or none. I think the intent is shown in the description for the faculty advisors:

"Faculty Advisors may not design, build or repair any part of the car."

Already it is very poorly defined, but the intent is clear. What if a university employees engineers not as faculty advisors? What if I was to not be the nominated faculty advisor for ECU, and instead that role was given to someone else. In my external design company I then started designing parts (or co-designing) for use on the FSAE car. I am acting within your definition of the allowances made to professional engineers. That means any alumni etc are free to be heavily involved in the design of components and subsystems as long as they do not consitute the whole car.

So me, a bunch of ex UWA mates, the ECU alumni design and build considerable sub assemblies of the car and deliver them to ECU for assembly.

A clear violation of intent. In a completely different class to parts such as professionally designed steering racks or the Drexler diff which, while designed externally for fsae they are made readily available at a fair market rate.

...

I was in a similar situation at UWA when we developed the first hydraulic interconnected system. It was a Kinetics system (using their patented system), but we designed and manufactured every component in the system. This included writing our own software for the calculations. Some converstaions were had, but no person at Kinetics had any engineering design input into of any part of the system. Quite frustrating to be asked at comp by a design judge (Oz) for the catalogue we ordered it out of. I do not mean the same offence to you.

At the end of the day we were able to design, build and test the system based on nothing more than publically available knowledge. We also did not request any provision to be the only team able to use the system.

My question is could the same be asked about the tyre design. You made the comment that the design of these compounds required highly specialised help.

I do not think there is any violation on the basis of manufacturing of the tyres, only on the basis that from your comments indicate professionals were required for the design of the tyres.

I also think there are a lot of teams violating the intent of the rules. There have been examples in engines, chassis and probably just about every system. For example you can design a carbon chassis including all tooling etc and have it manufactured, but there have been clear cases where there has been significant professional involvement in the design process. I think this is a breach of the intent of the rule as well.

Unfortunately there has been no case I am aware of where this rule has been enforced, or any idea of what the penalty would be. Maybe it shouldn't be in there at all, or maybe there could be a better definition.

Kev

Kevin Hayward

09-03-2014, 03:24 AM

I have attached two pictures to this. One that shows the increase in teams over the years (from the world rankings), as well as the increase of number of rules pages. Secondly I have attached a picture that shows the increase in the number of teams each year, vs the increase in the number of rules.

The total of teams is a little off towards the end as there are a few teams listed both in electric and combustion rankings. It is probably fair to say that the rate of increase in the number of teams has begun to drop after around 2010.

Some interesting points:

- First up the rate of growth of the competition is incredible. I am not aware of how many universities there are in the world, but almost continual growth at around 36 teams every year for 13 years is impressive. I wonder what the sturation point is. It is helpful to note that at the start of the data there was only 1 comp, by the end there were 11. There is also a bit of a pattern where once the number of teams per comp hits close to 60 a new comp will be formed. The average number of teams per comp tends to range between around 50-60 (except for the period with only detroit). This indicates over time the growth has come from rolling out the competition to new places, rather than an increase in the number of mega-comps. Obvious next steps could be official comps in India and China. I am aware of interest in Malaysia. Maybe extra consideration should be given to improving the situation of comps world-wide rather than a particular focus on the issues of the larger comps.

- In the period of decreasing rules (2006-2009, although 2006 is the local peak) there were 174 teams added, and an additional 4 comps started. For comparison in 2002 to 2005 (the previous four years) there were 2 comps added and an extra 119 teams. In the following four years (2010-2013) there were 2 comps added and an extra 139 teams. The compeition had it highest gross increase during the period of rules reduction.

- The two best years for growth were 2007 and 2008, both of which were in years where the rulebook decreased in size. 2006 was the next best year and had a larger rulebook than 2005, however there were 2 big comps added in that year (Germany and California)

- The two worst years for growth (2011 and 2013) coincide with the largest increase in the size of the rulebook. 2011 was the previous big aero change, 2013 added Percy legs, and a host of small changes. These were also the years of alternative frames and then EV inclusion into the main rulebook.

- The next 3 worst growth years were 2003, 2005, and 2009. I don't have the rules for 2003, but 2009 was the year chassis templates were introduced. Excluding the 2009 template rules addittion and looking at the 3 other years with the decreasing rules pages and you see the 3 best years for growth in FSAE (40 more teams than the three best remaining years)

- The addittion of EV's has not increased the overall growth rate, more clearly it appears that there is a conversion of old teams to EV.

...

Make your own mind up, but is that decent enough data or evidence to at least suggest that simplifying rules, and avoiding too many big changes helps the health of the competition?

At least if your goal is to provide good practical engineering training to as many students as possible.

Kev

http://i.imgur.com/6zmrJ6e.jpg

http://i.imgur.com/dxGfKTk.jpg

JulianH

09-03-2014, 04:19 AM

Another thing about the development of compounds. It's not something that you just 'do'. I don't think any team will be able to do this without a significant and highly specialized sponsor. There's a lot of reasons highly trained specialists design these compounds so therefore I'm not afraid that a team will make their own tire without a sponsor. You can always add a rule that the tires must be produced by an official tire company if you really think students can do this on their own.

How do you know that teams that used tire softeners have never had a rupture? It's something most teams wouldn't like to share on facebook anyway ;)

I assumed that "making a tire" is really difficult. Thanks for clearing that up. But as we have seen motors (Zwickau, Zürich) or even engines (OxBrooks, Auckland, ECU) developed by students, at some points, maybe even something like that will happen. Of course with an input of a tire company and their machines but well, at least if we let you guys do it "properly", we have to accept guys doing it by themselves...

True that a team would not write "Yeah, killed 3 tires today due to tire softening-tests, gonna repair the suspension and go on #softsoftsoft". But as I said, something like that has never happened at a competition in the last 5 years that I can think of.
If we would forbid the use of softeners in the name of safety, there is a lot that should be restricted as well...

Kevin,

I am all for deregulation - let the teams do everything that is safe.

But I think your linkage between "more teams if rule book is slim / less teams if rule book gets bigger" is imaginary. (In fact there is a study showing there is a correlation between the number of storks and the birth rates of countries...(http://www.researchgate.net/publication/227763292_Storks_Deliver_Babies_(p_0.008)))

If a new team starts the competition I can't imagine following scenario:
"Yeah we wanna build a FSAE car. Look here are the 2015 rules: Uff 176 pages. Last year it was only 135 pages.. nah let's not do it"

In my opinion there is a lot of different reasons why there is an increase in teams or not.. Like Hungary joining the WRL a couple of years ago "opening" the list for Eastern European teams. Now with Russia / India starting we will see a new push in team numbers with probably the same rules...

Kevin Hayward

09-03-2014, 05:32 AM

Julian,

I clearly state that the strongest correlation is between growth and the number of competitions. I also should note that the number of competitions is as per the world rankings site. In 2000 there were actually 3 competitions. Formula SAE / student has clearly grown on the back of more comps.

I did not make any statement that there was a clear correlation between regulation length and the amount of growth (although I admit I implied it). I pointed out particular data points, and asked an honest question as to whether this data suggests there could be a correlation between simplicity and stability of the rules and the rate of competition growth. I happen to think that there is and that your stork analogy is a little misleading. In that case there is no clear or expected relationship. Here we would assume that the regulations will have some impact on the competition, and one that may be able to be measured. There are very few data points to go by, which severly limits the assumptions that you can draw.

What I think you can state without bias is:

- There is no evidence that increasing regulation does anything to increase growth, if there is a correlation it would appear the other way.
- There was only one sustained period (i.e. more than 1 year) where ther rules were reduced in length. I now have all the rules as far back as 1999, and to 1979 sparodically, which confirms this further into comp history.
- In the period of international comps (i.e. 1998 onwards) there have been only 3 years (out of 18) where the regulations were made more compact (2007, 2008, 2009)

The obvious question is that if you don't use data like this what do you use to test the effectiveness of the rules documents? I am all for tracking number of incidents etc at comp, but I do not know of any stored non-anecdotal evidence. What about reliability as a measure to see whether teams are coping well with the rules? Hasn't got better over time. What about average number of rules queries?

We are encouraged to practice data-driven design practices, but collect and analyse no data regarding the effectiveness of the regulations. On another post it was suggested that the rules committee be seen as a steering committee. If that is so what KPIs do they use? I would say growth rate is a pretty good place to start.

If you take the stork/people analogy and assume that growth (or other improvement) is decoupled from the regulations, then why bother changing the rules? It would save a lot of people a lot of time. Alternatively if you say the changes to the rules have improved or hindered the competition, on what basis do you make that judgement?

I think this data should be shown. When the old hands talk about the increasing regulation and complexity there is often no data shown to back it up. This at least shows how the rules document has been increasing in size with data that can be peer reviewed. This is the first time I have seen this presented on the forum, and it at least shows a clear trend of increasing size of the rules documents. Between 2000 and 2010 there was an average of 2.7 pages per year added to the rules (7 increasing years, 3 decreasing). This in an increase of 33%. The five following years have seen an additional 68 pages added at an average of 13.6 pages a year, with no reduction in length in any year. An increase of 63%.

A reversal of this trend or at least some stabilisation may be a good thing for the rules committee to consider. I was speaking to a few design judges about the rules around the period of the rules reduction. There was a specific push from a number of the rules committee members to both clarify the regulations and reduce the number of regulations. What is very impressive is that under that committee they managed to add the whole chassis template sections while still reducing the overall size of the rules documentation. Their efforts for improving the rules probably have not been given as much kudos as they deserve. They fought against the trend and achieved their objectives of returning the rules to a more compact document. During that time the number of competitions and teams increased at a higher gross rate than any other period. This may or may not be linked to their efforts.

The lego company does provide a good example here. You may or may not be aware that as time went on Lego got into pretty big financial trouble. They had a product that was well sought after, but their product line had got overly diversified. In a restructure they consolidated and trimmed the fat. Non-profitable product lines were cut and the number of unique pieces sold drastically reduced. They have been going from strength to strength since that consolidation. Now "everything is awesome". Periods of consolidating what is important to driving the success of a venture is very important for the long term growth of organisations.

I will ask some simple questions about the data presented here. In 2011 the alternative frame rules were added to the documentation. In that year the regulations increased by 22 pages. Has the introduction of the alternative frame rules been a success? If it has what are the measures that show the success? How many teams have benefited by this change? What is the cost benefit relationship? On review of something like that you might find that some of the elements were successful and some were not. Maybe they should be kept as-is, maybe the useful parts could be folded into a more compact rules set, maybe they should be eliminated entirely.

Now that the aero rules have changed, what are the KPIs that will be used to measure success or failure of the changes? For the previous change there was an attempt to encourage teams to investigate aerodynamics. There has been mixed data back from that and it is nearly all anecdotal. On one hand more teams ran wings, but the story goes that many did so without implementing good design practice.

Turbo and supercharger rules have changed. What KPIs will be used to measure success / failure of the changes?

ETC rules have changed. What KPIs will be used to measure success / failure of the changes?

These are honest questions. I am legitimately interested in both the desired goals and how you can determine whether they have been met for a given rule change. I am also interested in what data we may want to collect as a community / organisation in order to provide evidence to show whether targets have been met, exceeded, or failed.

Kev

BeunMan

09-03-2014, 06:35 AM

Kevin, it will be very hard to differentiate between correlation and causation with the teams vs rules lines debate: Correlation does not imply causation. If we rename the vertical axis to 'number of pirates' it will still show correlation but implies nothing. You also need to take into account the dampening effect of Student Familiarity with the FSAE projects as more people know about it, less will be new entries. But this is solely something which relates to the number of total teams.

A better metric would be, assuming there is a correlation somewhere to be found, to take the new entries (actual participation) per year and re-entries as separate graphs. This way you can see the overall trend of the FSAE competition (getting new and more universities and colleges to participate) or the stagnation of the trend (more the same teams participate).

"- The addittion of EV's has not increased the overall growth rate, more clearly it appears that there is a conversion of old teams to EV. "

As building a EV car can be quite hard, as there (were/are) a lot more rules and regulations, it might not be the thing you would chose for from the start. But then, you can always do the "Challenge accepted" part of FSAE.

Wouldn't it be a good idea to take the final 2015 rules if they are there, sit down with a lot of (former) FS(AE) team members and reduce the rules to the minimal needed for safe racing, challenging builds and equal opportunities who do not solely rely on a big sack of money? Post those rules here and afterwards give them to the rules committee for their consideration?

Kevin Hayward

09-03-2014, 07:15 AM

Tristan,

I agree entirely regarding being able to confirm causation. I don't think the data is clear enough to make anything like that claim with any confidence. Not enough data points and too many other factors are included. Better metrics may help, but I doubt we would be able to confirm or deny causation with the data available. At this point it is presented for interest only, and maybe to stir a few pots. It could be that the rule instability has helped maintain growth, rather than see it fall over time (although I doubt it though).

I used the teams as per the world ranking for two reasons:

1 - It is readily available and able to be checked
2 - It is a measure of "how many institutions / students reached"

I think the total number of students reached is more important than how many of the teams are first timers. Some of us long termers may get fatigued by the comp, but at every university there is a constant stream of new students.

I think a metric along the lines of:

Quality of Education x Number of Students / Total cost

Quality x number as some sort of measure of total education benefit contributed by the competition. The equation becomes total benefit / total cost. I'm not sure where the girlfriends / boyfriends lost would fall into the equation. Maybe a negative term for social unrest :)

The number of students is reasonably easy to estimate and can be based on the number of teams. The total cost needs to have some input from institutions. The quality of education is much harder to quantify objectively. Maybe it can be collected by a brief student / university / industry survey at every comp. Offer a decent reward for entries; a small cost for valuable data.

Comp changes can be then measured on whether they reduce cost, increase participation, and improve quality. Participation has definitely been shown to increase, but has it outstripped cost, and has education quality improved?

This is a very similar metric to what Universities use to measure effectiveness. We monitor student satisfaction, cost per student, number of students, and benchmark learning outcomes, . Universities are also regularly reviewed by external professional bodies that assess quality of education based on work samples and accepted standards. Quality is the hardest measure to quantify, and to that end it is approached from various directions to try and eliminate subjectivity. Cost and numbers are relatively easy.

For all the problems Universities have they can be reasonably effective at measuring how well they do their job. Formula SAE / Student is advertised as an educational competition. Maybe some practices adopted by learning institutes could be applied to meet the same means. Anything that helps ensure that such a great learning opportunity is still around and thriving in another 25 years.

...

I like the idea of taking a razor to the rules, and doing so collectively. You mentioned some overall goals for the competition:

- Safe racing
- Challenging builds
- Diversity in builds
- No necessity for large budgets to be competitive

Are there any missing, can everyone agree on these?

Do we have clear agreed upon goals for the competition in general. Without those goals and targets to measure by, any attempt to alter the rules would likely degenerate into personal preferences.

Maybe a topic for another thread.

Kev

jd74914

09-03-2014, 07:28 AM

Example of why brace must at an angled no more than 45 degrees from the plane of the bent tube.

Thanks for the picture John. I agree that in this particular situation another member is needed, but what about the case where that forward roll hoop brace does not exist? As far as I can tell (and I may be reading/interpreting incorrectly), the side impact structure is now illegal?

GXP_Matt

09-03-2014, 09:26 AM

I agree. IC1.6.1/1.7.1 + 1.7.3 (Why should the use of recirculation valves be prohibited?! I honestly cannot find any reasonable motivation for that. Open blow off valves, okay, to prevent any chance of getting air in after the restrictor, but "closed" systems? Does not make any sense at all to me) + 1.16 (not more than 10% throttle during braking) basically prohibit the use of positive displacement superchargers. Completely. Turbochargers are less affected, but here the recirculation valve would have been needed as well, as an anti surge valve and simply to keep the turbo spinning, when the throttle is placed behind (and no open-throttle-anti lag system is allowed).

Why change the throttle position, which encourages the teams to use turbochargers, and then create IC1.7.3 which in combination with 1.16 makes the use of all kinds of turbo- or superchargers near senseless? I don't get it.

This confuses me as well. The reasoning behind the throttle moving behind the compressor that I heard was to make the turbo system more relevant to production cars which are becoming more and more turbocharged, yet you aren't allowed to use a recirculation valve? Which is an integral component of every single production gasoline turbo system? Without a recirc valve you put the compressor into surge every time you close the throttle, which will destroy the thrust bearing in short order. The only solutions I see are:

1. Replace the turbo every 5 hours of driving
2. Design a custom ball bearing center section to take the thrust load (no you can't buy a ball bearing turbo in the size you need for FSAE)
3. Switch to a diesel engine
4. Never let the throttle close further than 20% or so to keep the turbo from surging, maybe you could use some engine calibration magic to get this to work?

Were the rules makers trying to find a way to make implementation of the turbo more difficult so it isn't as much of an easy button? If so, I can think of way better options that don't drive such ridiculous workarounds/ rapid hardware destruction. It's like requiring teams that run carbon suspension to mount sharp pieces of steel that gouge the a-arms each time they move up or down.

apalrd

09-03-2014, 09:35 AM

4. Never let the throttle close further than 20% or so to keep the turbo from surging, maybe you could use some engine calibration magic to get this to work?

The new ETC rules specifically prohibit a throttle position >10% under 'hard braking', without any sort of reasoning or logic other than the EV cars can't run positive current in the same scenario. So, even though there's no technical reason to prevent this solution (and it's seriously a great thing to do, for all kinds of efficiency reasons as well) you can't.

GXP_Matt

09-03-2014, 10:00 AM

Yeah, but who in their right mind would run an electronic throttle with all those rules limiting what you can do with it? Tons of extra work for no reward.

apalrd

09-03-2014, 10:40 AM

Yeah, but who in their right mind would run an electronic throttle with all those rules limiting what you can do with it? Tons of extra work for no reward.

With an MTC throttle, you can't pull enough spark to idle at 20% throttle (which you would have to set the mechanical stop to to achieve this) and still meet the new 100 dBC idle noise limit.

Aren't these new rules fun?

JulianH

09-03-2014, 12:46 PM

Kevin,

I personally think that you don't have to "track" or "decide" if new rules are successful. If you still plan to do that, it can only be "How many incidents due to X happened the year before we changed the rule and how many occured afterwards?".

I'm way too young to debate you on this - in my period of FSAE, we had the introduction of Electric rules -> Did not change to much for us because they are based on the German rules and we participated at every German event, so the car was always built to their set of rules. And of course a lot of safety related changes caused by burning electric cars / battery packs and so on.

AF Rules are not really important - if you don't build your car that way, just skip them. I really don't care that the rules are 22 pages longer if I can skip those 22 pages.
EV Rules in the "regular rulebook" are the same - just skip them if you build an IC car.

In my opinion, the rules should guarantee safety and some major guidelines to have all cars in a small but exsisting variety. Minimal wheelbase is such a point, the restrictor for IC cars and the power limit for EV cars, but that's about it.

I like the idea of old FSAE guys re-writting the rules to kill all unnecessary stuff, but I will not participate in such a "committee" unless I know that the RC will listen to those guys.

If that will work, I'm part of it and I think it can help a lot... But I don't think it will ever happen.

DougMilliken

09-03-2014, 02:12 PM

As noted in another recent thread, I don't have any connection with the Rules Committee.
From my perspective as a design judge, a shorter and more concise rule book would certainly be welcome.

One convenient method for group editing is a wiki. For example, a new section could be added to the existing rules section of http://en.wikipedia.org/wiki/Formula_SAE -- paste in an ascii copy of the current rules and let everyone have at. If there are page limits on Wikipedia, then perhaps only the "currently contentious" sections of the rule book could be posted for editing & streamlining. Probably a good idea to keep backups in case Wikipedia decides they don't like this use of their servers...

Westly

09-03-2014, 08:37 PM

Doug, a wiki is not difficult to setup, with many teams I know of running their own private wikis for documentation, etc. I will shortly have my own server with a wiki to do my own development on, and it would be little effort to host one for something like a FSAE rules discussion, likely many other teams would have this ability too. It would be very useful tool as it tracks changes and they do revision history well in a colaborative environment.
Although as mentioned, there appears to be little regard for accepting involvement from anyone outside of the rules committee.

Julian, I believe that the rules require a defined set of goals and a method to track their effectivness. Otherwise how do know what are you actually trying to achieve and it is actually improving. They purely become personal opinion and lack basis or direction. As I have mentioned earlier (or in the other thread), all competitions should be recording incidents, cause, severity or something along these lines to try and improve the safety of the competition (which is the greatest intent of the rules in my opinion). These facts can be used to determine the probability/ consequence involved and how to mitigate them.

Rules T3.5.5, does the note make any sense to anyone?

mech5496

09-04-2014, 04:07 AM

Rules T3.5.5, does the note make any sense to anyone?

Uhmmm.....NO! The wiki idea is great, I was also thinking taking a knife on the rules on a collaborative basis, so count me in!

Kevin Hayward

09-04-2014, 04:17 AM

Uhmmm.....NO! The wiki idea is great, I was also thinking taking a knife on the rules on a collaborative basis, so count me in!

I have started another thread to this end. Please start making comments, and/or volunteer to be an editor. We can start on the forums to build on an already active community. Having a good look through in the last couple of days and the task is pretty big. A lot of small contradictions and unnecessary cross references have crept in.

For example, here's one I haven't seen mentioned yet:

Penalties for Rule S4.16, S6.8, T3.22.7, T3.9.5, A5, are contradictory with A8.4.1.

Kev

apalrd

09-05-2014, 12:07 PM

To get some data to support the craziness of the ETC rules, I went out in a production car and collected some data of basic parameters, including engine RPM, vehicle speed, longitudinal acceleration (measured), brake torque (calculated from pressure), throttle angle, and pedal voltage. This particular car was an automatic, naturally aspirated, all wheel drive.

I found that, while I was able to get the car to -1G for over 0.5s (and -0.8g for approximately a second), at roughly 80% (gas) pedal input, the engine output torque target continued to follow the pedal in all cases (NO reduction in engine torque, at 1G deceleration and 80% pedal). The throttle remains approximately WOT, without any other torque reactions (let alone closing to the 9deg/10% specified in the FSAE rules). Power enrichment is active for much of this, as well.

I'm also beginning to capture stuff like this on my daily driver car (turbo mtx), showing how much pedal input is needed while on the brake (not surprisingly, it's a lot).

How do they seriously expect FSAE cars to downshift with 10% throttle? What about turbo cars? Why can't the driver stand on both pedals in preparation of a launch in accel (or any other event, for that matter)?

Jay Lawrence

09-07-2014, 11:11 PM

Good point regarding downshifts. There are already enough bad drivers going 'chudder chudder chudder' into corners because they can't blip properly without forcing such things on those who can. Without a slipper clutch, failing to rev-match can be quite unsettling, and downright dangerous (especially on a bike).

Westly

09-08-2014, 12:47 AM

- 2011 was the previous big aero change, 2013 added Percy legs, and a host of small changes. These were also the years of alternative frames and then EV inclusion into the main rulebook."

- The next 3 worst growth years were 2003, 2005, and 2009. I don't have the rules for 2003, but 2009 was the year chassis templates were introduced.

Kev: I have been creating a bit of a database of comp results for analysis and just pulled out the number of forfeits and withdrawals from Michigan Comp which I thought could be interesting: (Cheers to who-ever in Michigan releases all the results in xls!, with weight, no. of cylinders, allows some interesting analysis)

The number of withdrawals from Michigan seem to have a strong correlation to rules changes, 2009:template introduced, 2011: new aero rules, 2013: percy legs and other minor changes. Template changes seems to have had the greatest effect in recent years with 28 teams withdrawing or forfeiting their first year in effect
http://i.imgur.com/BPD14Sz.jpg

The results don't appear to show the rule changes having an affect the finishing rate in Endurance which I thought they might. They fluctuate around an average of ~38% with no discernible relationship in rule change years. (FSG and MI, 2014-2006).

Khanjee

09-08-2014, 12:06 PM

mhaupt14

09-08-2014, 12:56 PM

Can someone help me interpret/visualize how this rule may/may not change the front bulkhead support from previous years? Anything will help:

"[I]T3.20.2 The Front Bulkhead must be supported back to the Front Roll Hoop by a minimum of three Frame
Members on each side of the vehicle; an upper member; lower member and diagonal brace to provide
triangulation.
a. The upper support member must be attached within 50mm (2”) of the top surface of the Front
Bulkhead, and attach to the Front Roll Hoop within a zone extending 100mm (4”) above and
50mm (2”) below the Upper Side Impact member.
b. The lower support member must be attached to the base of the Front Bulkhead and the base
of the Front Roll Hoop.
c. The diagonal brace must properly triangulate the upper and lower support members
NOTE: Each of the above members can be multiple or bent tubes provided the requirements of T3.5.5
are met"

Thanks,

Mike

MCoach

09-08-2014, 01:31 PM

How do they seriously expect FSAE cars to downshift with 10% throttle? What about turbo cars? Why can't the driver stand on both pedals in preparation of a launch in accel (or any other event, for that matter)?

How am I supposed to do smokey, smokey burnouts using 10% throttle?
There's nothing that stops a cable throttle from using 100% throttle and brake input right now, why should ETC be limited? I think the burnouts might be incentive alone to use a cable throttle...

...on the serious side, this does disrupt some other maneuvers that affects cars with a clutch pedal such as blipping the throttle under braking as mentioned. There is no interlock to check for clutch actuation by the rules. And for all, "left foot braking" while still on the throttle to unsettle and balance the rear end as requested would not work.

We're still working on the noise complaint to the rules committee so hold tight...

apalrd

09-08-2014, 06:40 PM

can somebody tell me why does the turbo compressor has to be downstream of the restrictor. because last time i read that the choked mass flow rate is dependent on upstream pressure. so the compressor wont be doing any good by creating more vacuum downstream. instead now the restrictor will be choked at even lesser rpm because of higher VE which is a bad thing i suppose. or am i misunderstanding something ?

This rule makes perfect sense, actually.

As you said, mass flow is dependent on upstream density (temperature and pressure), and flow velocity through the nozzle. The flow velocity through the nozzle hits a limit at mach 1, which corresponds to a pressure ratio of roughly 0.528 across the nozzle (off the top of my head and assuming temperature is fixed).

So, in order for a restrictor to restrict effectively, the upstream air density and restrictor area must be fixed for all teams. Since the greatest air density possible is ambient air (of the ambient temperature and barometric pressure), and a poorly team-designed restrictive air filter/intake or pulling air from behind the radiator can only make things worse, it makes perfect sense for a fixed area restrictor to limit all teams at that competition to the same mass air flow.

So, you do in fact need to create vacuum downstream of the restrictor to pull air through it (without a pressure difference, what will motivate the air to flow into the engine?). Once the pressure ratio across the restrictor hits 0.528, then stop pulling vacuum because the restrictor has reached choked flow.

A turbo makes sense still, because it allows teams to hit choked flow continuously, at all (or the vast majority) of RPM points that the vehicle runs. A large engine (610cc) would reach choked flow at some rather high RPM, so above that point (in theory) the engine will follow a flat power curve and torque will drop off. So if you want to run a 300cc engine, you will never reach choked flow at any same RPM, but with boosting (turbo and supercharging), you can reach choked flow at all RPM points you use (assuming your 300cc engine can handle the peak cylinder pressures of running that much boost).

It's up to you to decide if the added benefit of reaching choked flow at low RPMs is even worth it, due to traction or mechanical or whatever reasons. Or you might decide it's worth it to add a turbo simply because you can't meet noise any other way (which is a very valid reason with the 2015 rules).

tromoly

09-08-2014, 08:02 PM

Can someone help me interpret/visualize how this rule may/may not change the front bulkhead support from previous years? Anything will help:

Mike,

Here is the rule from the 2013 rulebook:

T3.20.2 The Front Bulkhead must be supported back to the Front Roll Hoop by a minimum of three (3) Frame
Members on each side of the vehicle with one at the top (within 50.8 mm (2 inches) of its top-most
surface), one (1) at the bottom, and one (1) as a diagonal brace to provide triangulation.

The only differences I read is they added specific places where the support tubes must join with other tubes. Other than that, I don't think it changed the support locations all that much.

mdavis

09-08-2014, 09:33 PM

mhaupt14

09-09-2014, 03:14 PM

It seems to me like if your upper side impact tube is not within 4" of the top of your FRH, then your upper front bulkhead support tube will not be able to tie to the top of your FRH. This could drastically change the front end of the frame designs, as I don't think any of the frames that I built would meet this new rule...

This was my concern. I was unsure as to whether this was more of a rule change or simply a clarification. The front end design would then be more complicated if teams still chose to throw tubes from the top of the FBH to the top of the FRH and then their "upper Front bulkhead support" would have to be triangulated in accordance to the weird 45 degree triangulation rule back to the range around their Upper Side Impact Member.

I feel, if a team wished to keep it simple (like most designs previously were), they would have a very odd looking front end being that most Upper Side Impact Members are much shorter than the FRH heights. This also may introduce awkward geometry in order to clear the leg template, and introduce problems for teams who mount their dampers and rockers on top of their frame in the front.

Either this is the case, or I'm completely misunderstanding the rule... Again, any insight will help.

Thanks,

Mike

AxelRipper

09-09-2014, 09:02 PM

http://i.gyazo.com/6d9a1ec7ca535a1929f99bf869571224.png

Here is what I'm interpreting that as. Really restricts front roll hoop height to a max of ~21" pending the thickness of tubes. Our 2009-2013 car would for sure not pass (had a raised floor for suspension geometry where the side impact tubes were maybe 4" apart) and our 2014 car would be pretty close.

I don't understand why the rules place a zone of 2" UNDER the upper side impact tube though. 2" under side impact puts your side impact at the top of your front roll hoop. So the top of your roll hoop could only be at a max of 13.8". I don't know how you'd pass broomstick or be able to put your 13.75" tall front end template in there.

MCoach

09-10-2014, 10:13 AM

I think it's supposed to emphasize more designs like this and less like the way we've done it.

Bemo

09-11-2014, 02:14 AM

That's exactly how I would interpret the rule. People who come to the conclusion, that this rule restricts front hoop height or something like this have a too narrow sight, how the front part of the space frame can look like. This is only the case if your front bulkhead support and the front hoop bracing are the same tube. Some concepts will be hard to maintain, but it's not a change comparable to the introduction of the footwell template.

I guess the reason for this is, that the rules committe doesn't want that in case of a frontal crash the load coming from the front bulkhead support is introduced to the top of the front hoop which will has to take a bending load if there is no structure above the side impact structure (which is not required by the rules). I don't say this rule is necessary to be this strict. Another possibility would have been to say that if the upper front bulkhead support is higher than the side impact structer another tube from there to the point were the upper side impact member meets the main roll hoop is required or something like this...

jd74914

09-11-2014, 02:14 PM

I agree with Bemo, the intent of this rule is definitely to prevent bending loads on the front roll hoop in the case of a frontal impact. What I don't understand is why this is necessary; since when have frontal impacts been an issue? The only frontal impact I've seen that was dangerous was the Korean team at FSAEM 2013 with a bolted IA bulkhead plate which came into the cockpit when the bolts broke.

The rule does seem very much too restrictive in that many (most) teams have a member which runs to near the top of the front hoop from the rear hoop direction for frame stiffness reasons. I don't understand why this is not considered acceptable by the rules committee unless their wording here is a poor way of saying that they want this tube to be of side impact wall thickness.

AxelRipper

09-11-2014, 08:35 PM

OH. I just realized I read that wrong. For whatever reason I had read the "The upper support member must be attached within 50mm (2”) of the top surface of the Front Bulkhead" as being the front roll hoop. So yeah, it pretty much just serves to disconnect the use of the upper tube as the front bulkhead support (which we had done on pretty much every chassis since the template rules).

MCoach

09-12-2014, 12:39 AM

FYI for anyone who wasn't aware...

The F1 technical regulations are about 100 pages shorter than the FSAE rules.

Bemo

09-12-2014, 03:24 AM

And the award for the most wrong and senseless comparison goes to...

How many of these pages are the rules for EV, how many for static events, how many for dynamic events?

If you want to compare that you have to sum up the technical and the sporting regulations of F1. From the FSAE rules you have to subtract the EV rules. Then the difference all of a sudden will not be that great anymore.

Jonny Rochester

09-12-2014, 09:21 AM

But F1 are hybrid and run both electric and combustion. So comparisons of the total rulebook are valid.

Kevin Hayward

09-12-2014, 10:14 AM

Bemo,

Because you asked:

Ev 25 pages
Static Events 30 pages
Dynamic Events 23 pages

Total of 78 pages. If the F1 rules are about 100 pages shorter than the FSAE rules these sections do not cover the excess rules.

For interests sake I checked out the CAMS manual (Australian motorsport). If you take all of the general requirements, add in a racing class, add in sporting regulations etc you still end up with around 100 pages.

The FSAE regulations are long, and are getting confusing with different areas addressing the similar issues. For example:

T3.31.1-2 deals with 275mm of the side impact zone being equivalent to 2 tubes.

Later we have:

T3.34.1-3 showing that a section of up to 320-330mm needs to be equivalent to 2 tubes, with a floor equivalent to one, and the whole section (side and floor) equivalent to 3 tubes.

We have about 1 page total of rules in two separate sections talking about the same requirements, with some redundancy.

There is no shortage of these examples. While they can be interpreted and understood, they do not have to be written this way. They can be shorter with improved clarity.

Kev

Dylan Edmiston

09-12-2014, 12:30 PM

It is acceptable to have a jumper harness which you install during technical inspection in order to allow demonstration of the plausibility functions for IC1.12.6 and IC1.13.7.

The response I got regarding the separate connectors for ETC sensors. I'm really glad they will allow us to do this because it will help simplify the harness to use a dual output sensor on a single connector.

Attached is a drawing I made as an example of the jumper harness (attached with the rules question I submitted).

edit: I just realized I'm dumb and showed red as ground. The point still gets across though...

MCoach

09-12-2014, 01:15 PM

Woah, woah, woah, guys. Not trying to start a war here, just throwing out a number from when I went looking for information and thought, "huh, that was short and concise".
Calm down, Bemo. :P

As an update on the noise testing and protest on our end, it turns out that in the US, all cars are tested using a 20" distance from the tailpipe and must be quieter than 95dBA. However, they have much larger, lower revving engines and are able to sound loud while still passing because they push a lot of their frequency lower, well away from the dBA ideal test range...much like the single cylinders for FSAE...just a lot less blatant about it.

We have tested at least 5 road vehicles which fail either the FSAE idle or test speed at this point....one of them happens to be our tow vehicle. But, they would still pass road requirements due to the difference in weighting. At this time, if anyone else would like to test on their own STOCK vehicles and either submit video proof of the vehicle test procedure and results and collaborate to submit a more comprehensive document, or give suggestions for easily obtainable vehicles which may fail which we could find at a dealership or friends to test, PM me.

Again, we're looking for completely stock (no cat-back, no headers, STOCK) road cars which may fail the new sound test. Either link me the video, or if not hosted on the internet, I can redirect you to my email to send the file. Another alternative is to upload the video to some place like Youtube and then point to that. Introduce yourselves, Name your vehicle and test speed, run your test, show the meter and the test rpm. This is the start of the official "My Road Car is Louder Than My Racecar" program and we're reaching out to help everyone who disagrees with the new rule set.

For reference, Idle is usually loader at fast idle from a cold start and test speed can be derived using the same calculation from mean piston speed in the FSAE rule book.
The vehlcles we've failed so far:
2013 Fiat 500 Abarth
2003 Nissan Sentra SE-R Spec v
2013 Ford F-250 Diesel
2014 Mustang Boss 302
2015 Charger w/Hellcat

mech5496

09-12-2014, 04:51 PM

I am pretty sure everyone expected that Hellcat to fail...at least I would be dissapointed if it wouldn't!

NickFavazzo

09-12-2014, 10:13 PM

Objections to including standard road bikes in this? since we do use similar engines?

MCoach

09-12-2014, 10:39 PM

Nick,

If you have them on hand, bring them out!
I'd actually be interested in what the stock application of these engines put out with reference to noise emissions.

NickFavazzo

09-12-2014, 10:42 PM

I work at a yamaha dealership so I'll get my hands on a meter an measure what all we have. Measuring as per FSAE rules correct?

apalrd

09-13-2014, 08:35 AM

I work at a yamaha dealership so I'll get my hands on a meter an measure what all we have. Measuring as per FSAE rules correct?

Yes.

0.5m (19.5") from the tailpipe, 45deg angle to the stream, parallel to the ground

Measure all idles (including warmup/fast idle) and noise test speed (~915m/min mean piston speed).

bob.paasch

09-21-2014, 07:51 PM

Yes.

0.5m (19.5") from the tailpipe, 45deg angle to the stream, parallel to the ground

Measure all idles (including warmup/fast idle) and noise test speed (~915m/min mean piston speed).

No video, I'll try to get that next time. But numbers for a stock Honda TRX450. Less than 50 hours, so the muffler should still be good.

Fast idle on start-up: 101.2 dbC (93 dbA)
Slow idle (warmed up): 98.0 dbC
FSAE test speed: 111 dbC

So no pass for a stock Honda 450 quad.

Kevin Hayward

09-22-2014, 02:18 AM

Out of curiosity is anyone aware if any noise measurements were taken at comp (or elsewhere) in order to determine if the new sound limits were reasonable?

Is it likely that this has come from a standard somewhere?

Kev

Mbirt

09-22-2014, 07:54 AM

No video, I'll try to get that next time. But numbers for a stock Honda TRX450. Less than 50 hours, so the muffler should still be good.

Fast idle on start-up: 101.2 dbC (93 dbA)
Slow idle (warmed up): 98.0 dbC
FSAE test speed: 111 dbC

So no pass for a stock Honda 450 quad.Wow! There you have it people. This is something you should be more up in arms about. Thanks for performing the test, Bob.

For a measurement as quiet as idle, dBC is not the proper scale to use--dBA makes more sense at this SPL. I discussed the FSAE dBA-dBC switch with the representative from HEAD Acoustics at Clean Snowmobile 2014 and he gave excellent input. Kaley should get the rules committee in touch with the representative from HEAD because this is yet another area where the rules committee needs to increase its depth with some external advisement.

Kevin,

The noise test at FSAE Lincoln 2013 was recording dBC measurements, but it appears to me that the data was not effectively analyzed or even looked at in the creation of this rule change. Our car, one of the quieter singles on track, tested at 109 dBA because I didn't change the cal or play with tailpipe placement. The dBC measurement was 117. Louder singles were passing sound and pushing 120 dBC. This led me to believe that 115 dBC might be the reasonable round number they settle on to keep loud singles in check.

Concerning standards using dBC, even the hearing protection industry uses dBA because, while dBC might be how we perceive loud sounds, dBA more closely fits the hearing damage limit of the human ear. http://www.howardleight.com/images/pdf/0000/0260/Sound_Source_4_AC_WeightedMeasure.pdf

Bemo

09-22-2014, 09:01 AM

Who said, the change from dBA to dBC is made due to the risk of hearing damage? Quieter cars make it easier to communicate at the track while cars are running. If you ever worked for a whole day in the Autocross queue and had to talk to team members all the time while engines are heated up everywhere you will know what I'm talking about. If you want to have an improvement according to this the singles are the ones you have to make more quite not the fours. To make it not this hard to meat the number it would have been propably reasonable to increase the number somewhere in the range of 115 dBC. But in general I think the switch to the dBC scale makes sense.

When I was an active team member the points for fuel were increased from 50 to 100 what basically meant, that we would immediately lose 50 points compared to a team like Delft who were our big opponents back then. We would have been happy to trade that for a lower sound level which only adresses our concept. But people love to complain...

apalrd

09-22-2014, 09:07 AM

Who said, the change from dBA to dBC is made due to the risk of hearing damage? ... But in general I think the switch to the dBC scale makes sense.

Every vehicle noise standard I have found (except FSAE) is noted in dBA and not dBC, as hearing damage is usually the concern.

In any case, the new 100 dBC idle is completely out of the blue from the RC, with no justification (and I think the RC *needs* to address this).

Bemo

09-22-2014, 09:32 AM

apalrd

09-22-2014, 10:10 AM

No offense, but this discussion is kind of stupid. You are supposed to put a bigger muffler to your car and your major argument is "but I don't want to"...

It's not 'I don't want to' it's more like 'I have to drop 20 dBC and triple the size of my muffler and reduce idle misfire and ... and ... and .. because of a drastic change in the noise limit well after the design of the 2015 powertrain has begun because the rules came out so late. We are supposed to be building racing cars 'for a weekend autocrosser', yet we're well under the noise standards of major racing series, and even under street car or off-road vehicle standards.

I think it's reasonable to ask the RC why they felt an idle noise limit is required, how they determined 100 dBC was adequate, and how they determined 110 dBC was adequate as well. Unfortunately, there's really no way to question a rule or email the RC directly.

Since they obviously studied the noise of cars in 2014 and 2013 in both dBA and dBC, they thought through the issue, they warned us about switching from dBA to dBC, we thought they would adequately study the change based on the data they took, and they ended up with seemingly random numbers and an idle noise limit out of the blue.

Usually street noise limits are set by hearing damage to nearby property, and the noise limits are evaluated for their hearing damage potential at the distance from the vehicles that people are.

At both US FSAE event venues, the Formula SAE vehicles are the quietest vehicles that the track will see. Lincoln is an active airport, with planes taking off just past the competition boundary, so the FSAE noise is almost a drop in the bucket at some times to aircraft noise.

Yannick

09-22-2014, 12:05 PM

Hi guys,

you may want to look at this old post from Tobias Michaels Blog:

http://tobiasmic.blogspot.ch/2013/09/rules-corner-possible-rules-changes-for.html

it's from 2013

Cheers,
Yannick

Kevin Hayward

09-22-2014, 12:27 PM

Yannick,

Thanks for the link, it clearly explains the justification behind the move. It would be great to see this communication made officially where possible.

The part about sustained exposure to noise levels from the track workers was interesting. A distance of 5m away is quite close. I wonder if it becomes sensible to provide ear protection to all marshals under these conditions. It isn't likely a problem for the small competitions, with cars passing quite infrequently past marshaling points. Ear protection can be combined with radio gear to keep communication lines clear. The cost could be considerable, but would be amortised over many teams and competitions.

Kev

mdavis

09-22-2014, 03:00 PM

What was the justification of the old limit? What is the justification of the noise limit for street cars? If you limit it to 110 or 115 or 120 dBC or dBB or dBA it is also out of the blue. The whole procedure of the noise test is out of the blue. So what? The limit of 610cc displacement is out of the blue. Why do you think the RC has to justify that they want the cars to be quieter?

If the addressed problem is to quiet down the track to make it easier for track marshals and others to communicate the switch to dBC makes perfect sense (I am not part of the RC, so I don't know what really led to the change, I'm just guessing as anybody is).

No offense, but this discussion is kind of stupid. You are supposed to put a bigger muffler to your car and your major argument is "but I don't want to"...

Bemo,

Were all single cylinder cars that you were near too loud? Or was it only a few of them? What I noticed in 2013 (I was also in the dynamic areas when cars were warming up/running), is that only a few cars were actually loud. The rules clearly state that if an official believes a team to be in violation of the noise rules, they can be re-tested. Why not enforce the rules that are currently in existence? Why continue to add more rules? If a team is loud (because they are cheating, and have pulled the plug from their exhaust), then go re-test them. It's a simple procedure that doesn't seem to be followed. Instead, all teams will be punished for the actions of a few.

It's not 'I don't want to' it's more like 'I have to drop 20 dBC and triple the size of my muffler and reduce idle misfire and ... and ... and .. because of a drastic change in the noise limit well after the design of the 2015 powertrain has begun because the rules came out so late. We are supposed to be building racing cars 'for a weekend autocrosser', yet we're well under the noise standards of major racing series, and even under street car or off-road vehicle standards.

I think it's reasonable to ask the RC why they felt an idle noise limit is required, how they determined 100 dBC was adequate, and how they determined 110 dBC was adequate as well. Unfortunately, there's really no way to question a rule or email the RC directly.

Since they obviously studied the noise of cars in 2014 and 2013 in both dBA and dBC, they thought through the issue, they warned us about switching from dBA to dBC, we thought they would adequately study the change based on the data they took, and they ended up with seemingly random numbers and an idle noise limit out of the blue.

Usually street noise limits are set by hearing damage to nearby property, and the noise limits are evaluated for their hearing damage potential at the distance from the vehicles that people are.

At both US FSAE event venues, the Formula SAE vehicles are the quietest vehicles that the track will see. Lincoln is an active airport, with planes taking off just past the competition boundary, so the FSAE noise is almost a drop in the bucket at some times to aircraft noise.

This, especially the bolded portion. The noise levels generated by most SCCA autocross cars is also far in excess of what most FSAE cars make (except those cheating the noise test). Yet people stand similar distances from their tracks, and nobody complains about hearing damage.

I have a feeling there will still be very loud single cylinder cars, while they are on track. Yet, these same cars will likely get through the noise test without any troubles the first time. If they get re-tested after the dynamics, I have a feeling they will fail miserably. Not because of packing burning up, but because they were not given the chance to re-plug their exhaust...
-Matt

jd74914

09-22-2014, 03:23 PM

Yannick,

Thanks for the link, it clearly explains the justification behind the move. It would be great to see this communication made officially where possible.

Kev

It explains the move to dBc well (which in my opinion is totally reasonable), but not the new idle limits. I feel like it is the idle limits which make little sense as many stock street cars and bikes (shown here and in our own testing) do not meet these rules.

Michael Royce

09-22-2014, 04:52 PM

Let me chime in with a little history (and stir things up).

Someone has asked why we don't have trackside noise measurement "like SCCA Solo" or (SCCA road racing). In both cases these measurements are taken at a distance of 50 feet from the edge of the "racing surface". Any transgressors are given a warning and told to fix it. FSAE used to have a measurement system like this up until about 2001 or 2002. We had a dynamic (pass-by) test to get the tech sticker and then cars were monitored during actual events, and many times were DQ'd for being over the limit. They had passed the official test and then got DQ's during an event. This resulted in many very unhappy teams! .

At the second FS event at the NES in Birmingham in 1999, John Hoole, the MSA scrutineer assigned to the event, who was also an MSA noise scrutineer, pointed out that the MSA used a static, ½ metre test at 4000 rpm, which seemed to do a good job for their road racers. He agreed to do a comparison of the then current FSAE test versus the MSA test. We picked a piston speed of ⅔ of the red-line (equivalent to 4000 rpm for a typical road car that has red-line of 6000 rpm). The correlation was reasonable, and the test procedure was simple, repeatable and possible for any team to carry out. So the test procedure was changed. No problems for about 7-8 years. Then we started getting singles, and singles are the problem!! The workers have been complaining of the noise of the singles at idle and low speeds, not at high speeds. The first complaints I heard of were from the skid-pad workers, and then from those working the start of Endurance as the singles sat at the starting line. The problem is the massive attenuation that the A scale gives at the low frequency of a single at idle. Tobias explains it very well in his blog.

I know that the Rules Committee has done some significant survey work on this, although I have not seen the results. But the numbers have not come out of the blue.

I have just measured my D Stock 2005 Cooper S, which is fitted with a SuperTrapp, it is comes out at 99 dBC and 84 dBA at 1100 rpm (warming up), and 94 dBC and 78 dBA at 8-900 rpm (warmed up). It is plenty noisy on a solo course.

What does this all mean?

A). You need to get your engine calibration so you have no miss-fires!!
B). You run the noise test with a warmed up engine.

A) and B) mean that your calibration person needs to do a good job.

And it might well mean that simple absorption/glasspack mufflers will not be good enough for singles. Teams are going to have to do a little muffler work and maybe start using mufflers with resonance chambers rather than pure absorptive ones, i.e. some real engineering work!

Michael Royce.

PS. The ½ meter test is simple. I know, because I do it on the Moto GP bikes at IMS and COTA!

Jay Lawrence

09-22-2014, 11:01 PM

As Kev suggested, why not give marshals some earplugs/phones? I'm sure that anyone standing near a PA speaker whilst someone is calling the race would be exposed to more SPL than is provided by the singles. What about drivers? Do all drivers now need earplugs as part of scrutineering, or just those driving singles?

To me the main problem here is that a team now cannot use an off-the-shelf muffler (for which there can be perfectly reasonable justification), so they must build one themselves. Cue the melting/falling off mufflers, and inherent (real) dangers that implies.

Swiftus

09-23-2014, 01:18 AM

Warning, this is somewhat off-topic.

I was neck-deep in the google machine looking at motocross mufflers and I ran across this image. The guy in the middle in focus looks so bored for being in the middle of a supercross race!

335

'I'm just standing here as dozens of motorcycles literally fly past me.'

Hehe. Made my night.

Bemo

09-23-2014, 01:38 AM

Bemo,

Were all single cylinder cars that you were near too loud? Or was it only a few of them? What I noticed in 2013 (I was also in the dynamic areas when cars were warming up/running), is that only a few cars were actually loud. The rules clearly state that if an official believes a team to be in violation of the noise rules, they can be re-tested. Why not enforce the rules that are currently in existence? Why continue to add more rules? If a team is loud (because they are cheating, and have pulled the plug from their exhaust), then go re-test them. It's a simple procedure that doesn't seem to be followed. Instead, all teams will be punished for the actions of a few.

-Matt

Believe it or not, we have done that multiple times at FSG and never caught a team really cheating. You can say whatever you want. The noise test was just not suitable as it was for keeping the noise of the singles down on track - end of story.

As Kev suggested, why not give marshals some earplugs/phones? I'm sure that anyone standing near a PA speaker whilst someone is calling the race would be exposed to more SPL than is provided by the singles. What about drivers? Do all drivers now need earplugs as part of scrutineering, or just those driving singles?

To me the main problem here is that a team now cannot use an off-the-shelf muffler (for which there can be perfectly reasonable justification), so they must build one themselves. Cue the melting/falling off mufflers, and inherent (real) dangers that implies.

You can run an off-the-shelf muffler. Just use a 4cyl. engine. You think your will be less competitive then? Oh, so you have to do the extra work. I don't see why it is the task of the RC to make it easy to run a single.

Mbirt

09-23-2014, 08:26 AM

Maybe the eye and nose-burning HC emissions will become the next objectionable racecar characteristic to strip away through the requirement of an oxidation catalyst?

Anyone that has heard a stock dirtbike or ATV with the "pea-shooter" exhaust restriction in place will know how quiet the TRX450R Dr. Paasch tested is. This vehicle is given a "green" sticker in California because it meets the state's noise laws for operation on public land. It is quiet enough for operation on land owned by the People's Republic(!), but not at an FSAE event.

I do not think this rule will last more than one season in its current state.

apalrd

09-23-2014, 10:29 AM

I have just measured my D Stock 2005 Cooper S, which is fitted with a SuperTrapp, it is comes out at 99 dBC and 84 dBA at 1100 rpm (warming up), and 94 dBC and 78 dBA at 8-900 rpm (warmed up). It is plenty noisy on a solo course.

While I was noise testing the Abarth, I hooked up some instrumentation from work to look at ECU parameters including air charge and spark advance.

Just idling, cold (light off idle), the spark was retarded past TDC, and the noise was extremely loud (some garage mechanics mistook it for a Hellcat or other loud V8 car when it started cold), but as it warmed up and ran less spark reserve, it quieted down significantly (and the noise results showed nearly 8db quieter when it exited light-off). A lot of this is the turbo interactions with retarded spark, but it passes the relevant noise standards where it is sold (in Michigan that would be 95 dBA at 20" in a 'stationary run-up test'). This car fails the FSAE standard noise test at light off idle, but is under 100dBC at the noise test RPM. Once it gets up to the high load regions, and the wastegate opens, noise goes way up, but that's not part of the noise test. Maybe turbocharged vehicles are seen as louder because of the wastegate interactions?

Many FSAE (and racing vehicles in general) optimize their cam profiles for high horsepower performance, including high RPM pulse tuning/gas dynamics. At low speed, and idle, all of these nicely tuned gas dynamics are not happy, and it can be hard to optimize the idle performance with a fixed cam engine, especially singles with their even unhappier plenum dynamics. The easy answer is to retard spark a lot for idle, which results in a nice stable no-misfire idle, but it's not quiet. So we can try to pull fuel or air and misfire, or sit happy and loud.

Mr. Royce, what is the noise standard for the Moto GP bikes you test?

Our towing truck is now going to be louder than our race car. Nobody complains about our towing truck being too loud.

Michael Royce

09-23-2014, 11:19 AM

Andrew,
The noise test for Moto GP bikes, is a bit of a farce. In my opinion, it is only to say they have a requirement! So I decline to give you the numbers or the test speeds!! If you are really that interested, go on-line and dig them out.

BTW, ear protection is necessary to survive in pit lane at Moto GP events.

MJR

MCoach

09-23-2014, 11:34 AM

Because I just so happened to be looking at the MotoGP rules...

2.4.5.4 Noise Tests
1) Noise tests must be conducted in an open area with a space of at
least 10 metres between the motorcycle being tested and walls or other
obstacles. There should be a minimum amount of ambient noise in the
area.
2) The measuring equipment must be calibrated prior to the test and
recalibrated at regular intervals.
3) The measuring equipment should be placed 50 cm from the end of
the exhaust pipe and at 45 degree angle to the pipe either to the side
or above.
4) The maximum noise levels at all times are:
MotoGP: 130 dB/A
For convenience, the test may be conducted at a fixed RPM.
1 cylinder 2 cylinders 3 cylinders 4 cylinders
MotoGP 5,500 rpm 5’500 rpm 5’500 rpm 5’500 rpm

Charles Kaneb

09-23-2014, 05:31 PM

I have never owned a road car or motorcycle that would pass the 2015 FSAE sound rules (The rule in Massachusetts used to be 98dBA at 50' and I'd always be close). I doubt a stock 2.5 liter Subaru Legacy would pass either at idle or at speed and those are used as family cars all over the world.

Will Oakland University or Kettering University lend me a sound meter this weekend? I'd like to know how loud my 100 ICA kart is.

MCoach

09-23-2014, 07:24 PM

Charles, you can pick a sound meter up for several bucks at Radioshack.

Jay Lawrence

09-23-2014, 11:15 PM

Bemo, you kinda ignored the majority of my post but you've brought up an interesting issue: it is not the task of the RC to make it easy to run a single. Correct. It is also not the task of the rules committee to eliminate industry accepted products/methods (thereby defeating the purpose of educating engineers for the 'real world'). This is very similar to the weird ETC rules.

Bemo

09-24-2014, 01:00 AM

As people ignore most of what I write and just quote a single sentence, why shouldn't I.

At what point eliminated the RC an "industry accepted product/method"? There was none which could have been eliminated. FSAE vehicles are used differently from road cars and the whole test procedure is completely different. And a hint to all of you who are taking all this efford to make senseless comparisons with other vehicles. Noise of cold engines is not interesting. You do the noise test with a warmed up engine.

Road cars don't have 20mm restrictors, so they wouldn't be legal in FSAE although used as family vehicles all over the world!
Road cars don't have 5 or 6 point harness systems, so the wouldn't be legal in FSAE although used as family vehicles all over the world!
Road cars don't have a master switch on the side of the chassis, so the wouldn't be legal in FSAE although used as family vehicles all over the world!
Road aren't open wheeled, so the wouldn't be legal in FSAE although used as family vehicles all over the world!
Some road cars even use Diesel fuel, so the wouldn't be legal in FSAE although used as family vehicles all over the world!

Oh, did I mention that comparing FSAE rules to road cars doesn't make any sense?

There are a lot of stupid rules you can complain about, but this particular one is absolutely fine. There is a well defined test procedure and a defined value to fulfill. Comparison to race cars are also senseless (FSAE is not racing!)

And btw, when working in industry you will have to fulfill a lot of requirements you don't like and think they don't make sense. You still have to accept them. So this might be a very valuable exercise for you.

Jonny Rochester

09-24-2014, 08:51 AM

Comparison to race cars are also senseless (FSAE is not racing!)

Comparisons between race cars and a teams car for FSAE competition is valid and intelligent, it is not senseless. The main differences between a FSAE vehicle and other formula cars is mostly in size and scale. Just because the FSAE competition itself is not racing wheel-to-wheel, there is no difference between a time-trial car and a racing car.
In fact any car can be used for racing. The difference between a car and a race car is the number on the side. I can race my Corolla if I want, it just needs a number on the side (and safety equipment for whatever category I race). Whether I enter a time-trial or a race, it's still exactly the same car. FSAE does in fact have a number on the side, so race car it is!

MCoach

09-24-2014, 09:35 AM

I'm about done bickering about the proposed sound rules here as the trend seems to be "either everyone is for restrictions or against restrictions....as long they don't affect them."
I think it's absolutely unreasonable to take a engine that is quiet enough to keep the Californians happy, make it into a pseudo-race car powerplant, and make it quieter. That's been my point this whole time, not that it's hard, that it's unreasonable. I was fine with the 110dbA limit because that's right around GT cars and GP2 bikes, some real world connection there. So, I'd be fine with a 115 dBC limit. Let's do that to square some things up. It's a bit of a farce to base what the restrictions should be based on a fully exposed ear without hearing protection. Why is no one wearing hearing protection? That's silly.

In most race series, ear protection requirements are a given, you show up as a spectator expecting to shell out a few dollars for earplugs for the family or bring your own. It's part of the experience. Things that are loud are exciting. Dynamite? Exciting. Gerbils. Not so exciting. Race cars that shake the grandstands as they blister by burning gallons of nitromethane? Exiting.

In many parts of the world, sound is a major problem. The cities are loud, traffic noise seems non-stop, street bikes and modified cars tend to annoy fellow citizens, babies cry on a plane. But on race tracks, some people just can't get enough of it:

http://www.f1fanatic.co.uk/2014/07/04/exhaust-changes-considered-boost-noise/

If people want to quiet the vehicles down so that we no longer need to protect our ears properly during vehicle running and it's "a legit engineering exercise", I would welcome all of those proponents to come join the Clean Snowmobile Challenge. 100 db isn't that hard, it's just annoying in FSAE. In Snowmobile, with a WOT pass by, try to keep it under 75 dbA, that'll make you competitive and give a large area to learn from where subjective sound quality is also rated. Leave the sound competition to those concerned about sound on the trails and on the road, in all other cases tracks have their own noise limits which are different from road cars for a reason. My team's stock diesel truck pulling up in the paddock shouldn't be the loudest thing out there. I would also ask you to not similarly modify shop standards such that they are improved and no longer need safety glasses.

Is it useless to compare to a road car? Maybe. But comparing to what are considered real world customer standards? Absolutely a parallel. If I were designing a road car, I'd expect to have some restrictions similar to current or future road cars. If I were building a vehicle to be autocrossed on the weekend I'd hope the results are somewhat within their expectations. If I were building a duck, I'll be damned it should quack like a duck...not some hippy duck that only quacks at 70dBC because it's been decided that the duck building competition is not about building ducks because real ducks quack too much anyway.

I don't want to downplay that work and calculations that contributors have put towards these rules because I recognize serious thought has been put into this, especially by Tobias. I'm just saying it's been misplaced and/or overstretched a little.