2015 FSAE-Australasia

[Z]

And Auckland's performance without turbos, wings, and redundant cylinders can give some testimony to the value of getting the basics right first. It's a real shame about their endurance luck...

As for RMIT, ...

Matt,

I have been looking at the natsoft Enduro lap times, and wow (!), what might have been!

It looks like Auckland were stuck in first gear for the whole of the first stint, with many laps around 2:00(+). Then in their second stint, apparently run entirely in second gear, they were down to 1:39.4 on their best lap. By comparison Monash's fastest lap was 1:36.9, next fastest was Canterbury with 1:39.1, then Wollongong with 1:39.2. That Auckland car really is a beautifully neat and simple little car.

As for RMIT(C), I am disappointed they couldn't run any hard laps, mainly because I wanted to see how their Avons compared with (almost) everyone else's Hoosier R25Bs. While they did set themselves high goals with the transaxle and carbon-everything-else, I think they missed the big-picture design target by a country mile. If you are going to build a bespoke drivetrain from ground up, then build something that suits the needs of FSAE, NOT just a straight copy of F1. (Ie., why the N-S engine, the inboard-4(!)-spd-gearbox, and such low R%, when the turboed engine puts out a claimed, tyre-shredding, 65 kW (85+ hp)?)

Ah, what might have been. Always next year...

Z

[Shuff]

Z,
Few points to answer what should have been questions rather than assumptions.
The Genesis in this application is pretty much a square. The north south layout gives you an opportunity to have much better intake and exhaust geometry. Let alone mating a transaxle to it while supporting the chassis loads as well. The trans axle gears are modified off the shelf items, hardly bespoke. The layout has its own reasons for being the way it is and none of them have anything to do with copying. I thought the tire choice would have helped you work out they don't do things because others are doing them. Did you ask what the teams design targets were? obciously not.

[mech5496]

Shuff, it would be nice if you shared with us as well, as I find RMIT really interesting. Would guess that a bespoke drivetrain around would allow for a super-tight rear end (as I recall from my conversations with Rob Woods and Jon Burford back in 2011/12), which IMO is really desirable. Not flaming/criticising or anything, just curious

[Rory Hourihan]

- Missouri's amazing consistency in Endurance. Probably the lowest variation of first to last lap pace. Showed the value of experience in driving and competition, although I think they suffered in overall time due to the Australian tracks being quite different to what we see overseas.


Kev

We also had some teething issues with international travel and the competition format, weren't quite ready as we should have been for the format of design and cost. The track is a bit tighter than the US comps and our drivers had limited seat time leading up to comp. No excuses though. We learned a lot and some things that aren't too late to be implemented into the 2016 car. Our goal was to finish a little higher but we're content with the finish overall. Our big focuses for the past two years have been consistently finishing endurance and getting a more structured team... it is nice they get a 're-do' of sorts at endurance. I assume that's due to the size of the competition.

International travel definitely isn't easy, so thank you to all the teams that helped us out! Hopefully we'll be able to make the trip more frequently!

[Z]

Shuff,

Did you ask what the team's design targets were?

Much as I would have loved to ask such questions, I decided not to, because ... they were all too busy fixing the broken stuff.

But lots of time now available for such chit-chat, so:

What were the Team's design targets?
Was one of them "to win the comp outright"?
If not, then why not?

I don't mean any of above in a niggly way. (Honestly! )

I genuinely would like to know why such an obviously well resourced Team put so much effort in building so many complicated and expensive parts, most of which, frankly, would not make a skerrick of difference if they were not there.

Specifically (IMHO):
* ~85 hp + low-R% makes the car traction-limited around most of the track. If you start with a high-ish power engine, then should you not make sure the car can use that power, as much as possible (ie. MORE R%!)?

* With ~85 hp the Enduro can be run comfortably in one gear. Likewise, with that power and a lightweight car you would be at the pointy end of Accel and AutoX events with only two gears. So why four?

* Nothing I saw in the N-S engine's I-E system could not be used in an E-W layout.

* An E-W engine/drivetrain can use spur-gears (or belts/chains) everywhere. Much simpler and cheaper than the N-S layout's necessary bevel-gear-final-drive (as Albins told you). I understand the Team had problems with those bevel-gears well before comp? (Misunderstood pinion loads?)

* A reverse rotating E-W engine has significant gyroscopic advantages.

* A well packaged E-W layout has the driver much further back for a more compact car, with lower Yaw MoI, lower CG (driver more reclined), and less total mass.

* Spending less time/work/$s on UNNECESSARILY complicated transaxles (eg. why TWO sets of "drop-gears" in there?), gives more resources for aero, which is where the big gains are found, especially on lighter cars.

Maybe next year...

Z

(PS. I reckon the Yamaha Genesis engine is a reasonably good choice for FSAE (but not as good as air-cooled single... ), primarily because it comes with NO gearbox, so you can build a "good for FSAE" drivetrain.)

[Shuff]

What were the Team's design targets?
The team started the year very small, eg there were about 6 people. With some fair obligations to meet from the uni. So goals had to be realistic.

Was one of them "to win the comp outright"?
Of course, but the main focus was on design, a fresh start concept wise leading to better understanding of the engineering put into it, I think this was reflected by the design event result.


I genuinely would like to know why such an obviously well resourced Team put so much effort in building so many complicated and expensive parts, most of which, frankly, would not make a skerrick of difference if they were not there.
First off your main resource is your people. This team had a small bunch of extremely dedicated members, who put everything into this. The university provides some excellent resource in terms of an on site autoclave, a chassis dyno that works most of the time, and a wind tunnel that can be booked by the team about a month or so in advance. So yes rmit is well resourced, but the main focus of the project is using those resources to learn, how many students can say they have designed and built a carbon fibre tub? An entire engine package? Wind tunnel tested prototype parts for a race car, this team can because they bit off more than they could chew then chewed like hell. Carbon tub is a must for this team. a transaxle is a huge challenge, go for it. Two of our members final year projects, one the case and two the trans itself, were undertaken and proved to be a good punt as both have landed employment off this project. So actually a small amount of resource was and had to be placed in this project.

Specifically (IMHO):
* ~85 hp + low-R% makes the car traction-limited around most of the track. If you start with a high-ish power engine, then should you not make sure the car can use that power, as much as possible (ie. MORE R%!)?

Peak power, not used in every event nor all the time in any event. And yes still a work in progress,

* With ~85 hp the Enduro can be run comfortably in one gear. Likewise, with that power and a lightweight car you would be at the pointy end of Accel and AutoX events with only two gears. So why four?

Four gears were used to allow reversion to another engine setup if required throughout the development, which is still ongoing. May or May not be in there much longer.

* Nothing I saw in the N-S engine's I-E system could not be used in an E-W layout.

Possibly, but the intake runner geometry would be extremely difficult. As would service. Been there done that.

* An E-W engine/drivetrain can use spur-gears (or belts/chains) everywhere. Much simpler and cheaper than the N-S layout's necessary bevel-gear-final-drive (as Albins told you). I understand the Team had problems with those bevel-gears well before comp? (Misunderstood pinion loads?)
Again as above, however the drive off the crank has some factors which need addressing which have been with the n-s. Pinion loads were well understood, but, a lot of learning is still happening.

* A reverse rotating E-W engine has significant gyroscopic advantages.
How significant?

* A well packaged E-W layout has the driver much further back for a more compact car, with lower Yaw MoI, lower CG (driver more reclined), and less total mass.

Again possibly,but integration of the chassis engine and trans becomes exponentially more difficult ie more parts and hence mass required. If you are around next year seriously have a look at how everything is attached, it's pretty much one aluminium plate. Honestly if the driver was any more reclined they would hardly see over the wheel. It's a bit deceiving when the car is on the stands, it's really very very low. Also much of the time the tallest driver 6 foot2 is in the car. There is still a template rule that needs to be met. What would you expect the cog to be?

* Spending less time/work/$s on UNNECESSARILY complicated transaxles (eg. why TWO sets of "drop-gears" in there?), gives more resources for aero, which is where the big gains are found, especially on lighter cars.

Again one guy, who had to do it for his uni course so it's a must. But I can see that for an outsider it would be easy to think it was a whole team of people working on it. Aero is in the works don't worry about that, this is and has always been a multi year deal.



Maybe next year...

Definitely!!!

Z

(PS. I reckon the Yamaha Genesis engine is a reasonably good choice for FSAE (but not as good as air-cooled single... ), primarily because it comes with NO gearbox, so you can build a "good for FSAE" drivetrain.)

[Z]

Shuff,

"... the main focus was on design, a fresh start concept wise leading to better understanding of the engineering put into it, I think this was reflected by the design event result."

I have had another look at your 2015 car's specs, and also those of the 2014 car. Unsurprisingly, I disagree with the Design Judges' assessment. Some '14->'15 changes went in an ok-ish direction, some in the completely wrong direction, and some very easy and very useful potential changes were ignored.

Here I refer to the "big-picture" concept changes, although I note these did NOT hurt you. It was the messed up "details" that stopped you competing in the AX and E/F Dynamic events. But even if you got those details right, your '15 car would not have been much faster than the '14 car. (Edit: Given that the '14 car was ~20 kg lighter than '15, you may have been slower this year.)
~o0o~

"Peak power, not used in every event nor all the time in any event. And yes still a work in progress..."

This is a good example of where you missed the "big-picture target" by the proverbial country mile. Your spec, taken from the 2015 Program, lists the turboed engine having "Max Torque = 90 Nm @ 6000 rpm", together with a 10+ krpm redline. If that is even close to true, then you could have been spinning your wheels almost everywhere on track in top gear!

The point is, with this hi-torque-hi-rev-engine concept plus your low-R% concept, you had no need for the complicated-four-speed-transaxle concept. Instead of a dozen spur-gears plus two bevel-gears plus many shafts+bearings+++, you only needed a single chain or belt going to a two-spur-gear final drive (with a clutch thrown in there somewhere, of course). Much quicker, easier, and cheaper to build, and the finished car would be significantly lighter and faster. (And yes, even faster in Acceleration event, if done properly!)
~o0o~

"Four gears were used to allow reversion to another engine setup if required throughout the development..."

A N-A Genesis engine in a simple lightweight car would do just fine with a single-speed drivetrain. See Auckland's E2 times while stuck in 2nd-gear. The N-A Genesis has more torque and a higher rev-range than Auckland's engine...
~o0o~

"How significant [are gyro effects]?"

Easy to work out. I did ... and posted the numbers on this Forum several years ago.
~o0o~

"...[with E-W layout] integration of the chassis engine and trans becomes exponentially more difficult ie more parts and hence mass required..."

Nonsense. (And only Americans so misuse/abuse the word "exponentially"! Ughhh! )

Again, see Auckland's car for a very neatly packaged E-W rear end. Given that you had the opportunity to "build from ground up", your's could have been even neater still (eg. use much smaller "aluminium plate", turned sideways).
~o0o~

"... this is and has always been a multi year deal."

I hope you take the above comments in the right spirit. I realize that right now, having worked hard all year, and then falling at the final hurdle, you will be somewhat upset.

But I am wondering if RMIT-2016 will ever get back to where RMIT was in 2006 (= top of world)? You were reasonably close in 2014. But, to repeat the obvious, this year you went backwards.

Putting it another way, if Team-RMIT-2015 was a small business, then instead of organising a Christmas party right now you would more likely be chatting with the Receivers. Very expensive investments that produce miniscule returns do not maketh a good business plan. Your RoI this year was negative.

Z

[Shuff]

I'll make this quick.
1. Just because the program says something doesn't make it true. Ie mass and rpm.
2. A list of specs tells you nothing about the way the car will work as a system.
3. Honestly R15 is much faster than r14. Really
4. I'm not at all upset, as I stated this is a multi year deal and top of the world is were the team is aiming.
5. Adjustable boost is a wonderful thing.
I'm probably just reading you wrong, as far as I am aware there isn't a correct answer to this problem of Fsae.

[Shuff]

Z,
Holy shit you are deluded.

Seriously the aim of all this is to learn and get a job.

Job done

Ps yes I'm on uni holidays and bored as shit right now.

[Z]

... the aim of all this is to learn and get a job.

I found that "getting a customer" was much more profitable and enjoyable.

But that only works well, long term, when you set the right "big-picture" targets.

Z