2015 FSAE Rules

[mdavis]

As with any rule, you can be request to show compliance at any point during the competition. I think in case of engine noise they should do that, at the fines which the track gets are directly charged to the organizers (e.g. FSAE) which is not in the interest of ALL teams.

I do not know if that is the case with the US venues, as the MIS event regularly hosts NASCAR testing, which is incredibly loud, and the Lincoln event is held on an active airpark. There were several planes taking off, landing, practicing various maneuvers while we were competing. Even the loudest single cylinder cars were quiet in comparison.

The way I would like to see noise checked is where it matters most: on track with the car loaded up. This is the way that the SCCA (Sports Car Club of America) does their noise testing at the Solo Nationals event that is held in the same location as FSAE-West. From my understanding (I've never run a National event) they find a spot on the course where all cars are most likely to be at full throttle under the highest load and set up a mic 50' from the racing line. They then measure noise for all cars that go past. If a car is close (within ~5db), I believe they are warned after the run. This would make sense for the autocross event, where teams have 4 total runs with a slight break in between. If a team is close on a given run, then they are warned and they have a chance to talk with the driver/make changes to the car before the next run. If they go over, the run would be DNF'ed. IMO, for the endurance event, it would be best to provide some tolerance, and then anything above the tolerance results in a DNF (either for the lap or for the entire endurance event). 2 laps over noise and you're black flagged for Mechanical and done for the event. If you want cars to be quiet on track, this is a good way to do it. It's harsh, but it accomplishes the goal of quieting down cars. It would only take 1 event where teams DNF for noise before the word gets out and teams quit cheating the test by adding plugs to their exhaust for the current test then pulling them and running the competition loud.

Matt,

Looks like they could run the engine now without having to re-sleeve. Should offer similar advantages to the four, but with a narrower package (and maybe lower vibrations). I would love to know the base weight of one of the triumph engines. I am sure the judges probably disliked the idea of heavy customization to end up with an engine not much better than a standard 4 pot.

Definitely not as radical as building a powertrain around something like a BMW R65 engine. An aircooled boxer engine could make for an interesting change.

Opening up the options here doesn't hurt anyone, and definitely means more of the engines sitting around a wrecker will be suitable.

Kev

Kevin,

If this rule goes through, that would seem to be the case. I do not remember if their sleeves could be removed, but if they were able to (or have easy access for more engines) this would definitely seem to be the case. I think this is a good change for the competition. Singles are incredibly expensive, but something like a Suzuki SV650 can be had for 1/3 the price of a single cylinder, and you get the whole rest of the bike to scrap out as part of that deal.

I always thought something like the Honda Goldwing would make for an interesting engine for an A-Modified (SCCA class which is basically big FSAE car with almost no rules). Flat 4 (or 6 in the later versions), shaft drive right out the back of the gearbox, etc. There are a lot of unknowns in terms of aftermarket support, transmission strength, actual power capability (I've heard the top A-Mods are near 300hp) etc. etc. etc. Either way, still fun to think about.

-Matt

[Kevin Hayward]

While I dont think the particular change to the aero is a good one it is great to see a change to the rules that actually opens up possibilities, and forces teams to consider more trade-offs. New turbo trade-offs, rear wing / rear track trade-off, more available engines, powerful 2wd electric vs more control of the less powerful 4wd. It is amazing that changes like this require very few textual changes to the rules, especially compared to something like the alternate frame rules. From the look of it most teams will be affected which should cause a little bit of a shake-up. Some concepts will win, some will lose, and now that I am over my initial shock I am excited to see how it will all pan out.

As much as I have liked seeing the performance of the big winged cars (my team included) it was a bad rule change in the sense that it made aero devices compulsory if you wanted to do well. This definitely increases the cost of performing at the front (although not nearly as much as people complain about).

Kev

[Z]

... new rule set ...
According to Racecar Engineering...

- Smaller Wings (inside of the wheels instead of outside)
- Probably ban of unsprung aero?

FSAE Rules Committee Members to students;

"FSAE is NOT a Mini-F1 contest!!!
Now, you students know that FSAE is supposed to be about challenging your, err..., "Creativity and Imagination" to, umm..., build some sort of, err..., C&I car ..., or something...
So STOP THINKING OF MINI-F1!"
~o0o~

Meanwhile, FSAE Rules Committee Members amongst themselves;

Senior RC Member, "Well, looks like we are going to have to make some big changes to the aero Rules now..."

Junior RC Member, "Why?"

S-RCM, "Geez, haven't you seen this year's F1 cars!!! They've all got those narrow rear wing packages! Now that's because the narrow wings are much, much better at, umm..., well, something. It doesn't really matter why. But obviously it's something really important, innit?! I mean, they wouldn't have 'em in F1 otherwise, would they?"

J-RCM, "Yeeahhh... I guess so. They've got to be a good idea, ... 'cos they're in F1..."

S-RCM, "Yes, and we must get rid of that "unsprung aero" nonsense too. MADNESS!!! You never see any of that in F1, do you?!!!"

J-RCM, "Ok...
So I guess we should probably also include some definitions of what "aero", and "suspension", and "bodywork" are, so that there will be no confusion about what is unsprung..."

S-RCM (interjecting), "NO, no, no, no, no!
That'll allow some troublesome C&I students to come up with a really fast car that doesn't look at all like an F1 car. No way!!! Oh no, no, no. We have to leave ourselves a means of, err..., "discouraging" that sort of disrespectful heathenism!
Better to keep the Rules as vague as possible..."
~o0o~

- Larger engines (700cc)

J-RCM, "Now, about this engine capacity limit. Given that we already restrict engine power with the "restrictor", I don't think we need ANY capacity limit AT ALL..."

S-RCM, "What!!! Are you MAD!? What if a team comes with a 8 litre big-block V-8??? It's too frightening to even imagine..."

J-RCM, "Well, a big-block like that will have so much internal friction that, together with the restrictor, it'll be lucky to make as much power as a Baja-Briggs."

S-RCM, "No, no, no, you just don't get it.
F1 has all sorts of specifications that very tightly control the type of engine they use. So we have to do the same. Simple as that!"
~o0o~

- 2WD eCars with 80kW; 4WD eCars with only 50-60kW

J-RCM, "I've been doing some research, and it seems that the 20 mm restrictor is good for about 90 kW on the Combustion-cars. So no current disadvantage to them. And I was talking to some toothless hillbillies at the local drag strip, very nice guys BTW, and they say that a RWD-only C-car should be able to blow the 4WD E-cars away in the Acceleration event. So I'm not sure about this idea of lowering E-car performance?"

S-RCM, "Geez, you still don't get it!
This competition is about breeding an army of witless drones that will design the next generation of production cars. And we have already decided that the next-gen cars must be E-cars.
So we DO NOT want the students learning how to make the current C-cars faster, or more efficient. Instead, we want them
believing that E-cars are far superior to C-cars. So much so that the E-cars have to be severely nobbled just to get some equivalency in performance.
(And God help us all if anyone ever suggests that Enduro be lengthened, to show up the piss-poor real-life range of the E-cars. That must NEVER be allowed to happen!)"
~o0o~

The downward spiral continues...

Z

[Kevin Hayward]

Z,

The changes to aero I think are a performance restriction to counteract some of the performance added when they changed a few years ago. There are many ways to do this, and limiting the size of aerodynamic elements is a good one. I don't agree with the unsprung mounting restrictions, but it hasn't been clearly communicated that it is amongst these rule changes (maybe by implication only).

I'm not sure what your complaint about the bigger engines is ... as you state the restrictor already provides a limit. It might be a bad idea for students to use the bigger and heavier engines,b ut I like that it will be there mistake to make.

Lastly the big difference between the electric motors and petrol is not the peak power, but the sustained power. An electric car limited to 80kw will be able to do this through-out their rev range by the rules, meaning incredibly torque down low. An IC motor only touches it peak power for a small rev range (which is much smaller than the range you need to use in the acceleration). A CVT could make things better, but introduces issues of its own. However as I have stated previously keeping the classes separate is the only sensible approach. The electric cars are faster partly because the petrol cars are held back (especially by the restrictor, turbo location etc). It does not represent accurately the differences between IC and EV cars in the real world.

Kev

[Dunk Mckay]

Z,

The 2WD vs 4WD thing is a bit strange. But I would dispute the idea that the combustion cars have the potential to blow the e-cars our of the water in acceleration. Maybe a car designed purely for acceleration could keep up with the standard e-cars, i.e. a dragster that meet the regulations. But that car would suffer in every other event, and would not beat a electric dragster. The issue being toqrue curves, dropping power to shift gear 2 or 3 times costs as much a half a second, that yes, as Kev said a CVT would get back and even improve the torque performance. But ultimately it's not going to match the full-power-all-the-time of an electric motor.

If dramatically changing the power allowances for electric cars causes them to be at a disadvantage against combustion cars then great, all the more reason to separate out the classes at FSUK. if they're competing against each other it doesn't matter what their rules are as long as it's safe and cost effective for all universities that run them.

[BeunMan]

Note that most FSE cars run at much lower power ranges when driving the Endurance due to 'fuel' issues. E.g. taking enough power to driver at 85kW the entire course would make you car heavy... really heavy. So wins for electrics at Accel and AutoX, they are even at Skidpad and possibly in a disadvantage in Endurance but at an advantage in Economy when done properly. I think it will probably even out quite a lot.

[Swiftus]

I was thinking about this on my flight today. If the goal of the new rules is to encourage the use of turbos (which is the obvious choice when the order of turbo > throttle becomes the industry standard), then I hope there are additional fire safety rules added. Here is my line of thought, and I am kind of think out loud here.

Under the current rules set, turbo teams have a chore in keeping their systems well oiled under vacuum. Because their oiling systems, and therefore cooling systems, for the turbos are in non-ideal conditions, these teams are forced to either go for max performance and risk overheating and fire or minimize their risk and have an 'underperforming' turbo.

With the proposed rules, if the throttle / turbo order is rearranged to that of the industry standard, teams will no longer have such a tough choice in turbo reliability vs performance. I think this is the goal (because turbos are on every engine everywhere now). However, I think that making the decision to use a turbo (obviously you HAVE to turbo your car) a given will cause many teams who do not have the resources to develop a turbo car to dive in. And this is where I forsee many half-built turbo cars catching fire.

With the old rules set, a team would see a turbo as an option, think about it for a minute and then come to a conclusion like "unless (insert industry engine manufacturer) helped us develop a custom turbo, there is no way we have the ability to make a turbo car. Better use a NA 1-2-4 cylinder because of x,y, and z."

The new rules set would allow turbo cars to make more power for the same economy, or the same power for better economy (its what they do), without the drawback of having to completely design your own turbo system. I fear the ease of entry into the turbo FSAE car market creates an atmosphere around turbos and their "industry standard reliablity" which is unsafe in the FSAE environment. I have personally witnessed a number of FSAE cars catch fire at multiple competitions, and more often than not they were carrying turbochargers.

When the rules are changed to match the "industry standard" I think the details get lost in the obvious. Real life example. When the automotive industry started putting catalytic converters on cars to improve the exhaust emissions, there industry managed to make the cars just as reliable and drivable as they had been before. So they started selling a bunch of these better emissions cars to the public. What they didn't realize is that the public was not going to think about what having a catalytic converter on your car actually meant. So people kept driving and parking their cars just like they always had. People would park their cars in front of their house on a nice and brisk fall day, walk inside and soon look out the window to see their car completely engulfed in flames.

Auto manufacturers made sure to keep the heat from the new catalytic converters out of the passenger compartment, but they completely missed the whole 'do not set fire to the leaves on the ground' part. And they got paid to implement a catalytic converter.

The problem was the benefits were obvious and the potential flaws were not. And any flaw within a volatile system meant for a lot of destruction.

I realize I am rambling but hopefully my point does get across.

TLDR: Changing the current turbo rules to 'industry standard' type rules will cause there to be many more half-attempts at turbocharging and result in many more fires.

[Mbirt]

TLDR: Changing the current turbo rules to 'industry standard' type rules will cause there to be many more half-attempts at turbocharging and result in many more fires.

Jay, we see this often as the price of admission is lowered. Carbon fiber becomes increasingly more available: more suspension points pull out of tubs during the brake test. Giant wings become almost mandatory to win under wide-open aero rules: more wings fall off during endurance, more cars crash due to aero balance issues that weren't sorted in design or testing. And so on.

The SAE CDS has experience dealing with students and insurers to allow electronic throttle control in the Clean Snowmobile Challenge and Supermileage, in addition to piping hot turbochargers and catalysts under full bodywork at the CSC. In 2013, as a 4-man CSC team, we undertook turbocharging and ETC on a naturally asiprated, manual throttle snowmobile with no major issues other than a cracked exhaust manifold weld after the 100 mile endurance. It was quite a successful vehicle despite our inexperience with turbocharging and ETC and a TINY team. I don't think the pre-2015 rules stopped underqualified teams from running turbochargers, they just weren't highly visible like the one thermal event-prone example of late you're probably thinking of. There are easier/lower-risk ways to manage the oil system.

Let teams focus more intently on their powertrains if they choose to do so--it's still no substitute for good vehicle dynamics, aero, test time, driver training/recruitment, and so on. Overall these proposed changes are very good for increasing the quality of the engineering experience.

Question--Is the intake plenum volume limit only for turbo engines with post-compressor throttle?

[bob.paasch]

Question--Is the intake plenum volume limit only for turbo engines with post-compressor throttle?

That is my understanding. NA engine would have no plenum limit, but also would still be required to have the throttle body upstream of the restrictor with the resultant plenum volume verses throttle response tradeoffs. Only supercharged/turbocharged engines get to move the throttle body downstream.

In my opinion, this change will have a similar effect as the aero rule changes 4 years ago: teams will have to super or turbo-charge to be competitive. The advantages to the throttle body move will be too great to ignore.

[apalrd]

In my opinion, this change will have a similar effect as the aero rule changes 4 years ago: teams will have to super or turbo-charge to be competitive. The advantages to the throttle body move will be too great to ignore.

We would still be limited to the same power limit due to the restrictor, and there are already many common FSAE engines which choke the restrictor naturally aspirated as is. The turbo still has a tradeoff of transient response, complexity, packaging, intercooling, calibration and controls, vs a larger displacement or otherwise higher power engine which is heavier.

Anyone aside from mbirt have opinions on ETC? No opposition?