Questions from First Year team

[Aaron@Kaist]

I have followed protocol and searched the forum, but could not find any answers to a couple of quesitons. Maybe my search method was incorrect but here it goes:

a) If we use a 2007 Yamaha r6 motor with a Motec ECU system, are there any limitations in terms of the engine not functioning without the originial ECU? I called the Yamaha service people and they tell me that there is some sort of integrated intake regulation system on the newer r6's which make it difficult. But I am not sure what is the deal with that.

b) If our team were to design a double chassis system similar to the lotus 88, when determining th side impact force it can sustain, it is the sum of the two chassis or just the inner chassis?

c) Does the engine have to be in the rear?

d) Generally how much carbon does a team buy to build a monocoque, and how much would a team need to be generally to build the body, general figures would be much appreciated, I know there are many variables, but just want to get an estimate for budget sake. The thickness of prepreg carbon we are looking at is 0.27 mm and is measured and sold in meters. is 42 US dollars a meter a reasonable price?

Thanks so much, I apologize ahead of time if these questions have been answered before, I simply could not find the answers.

In addition, if any school is selling motors or parts, please let us know we are in the purchasing stage of our project and any help with parts would be much appreciated.

- Aaron
Korea Advanced Institute of Science And Technology

[Aaron@Kaist]

I have followed protocol and searched the forum, but could not find any answers to a couple of quesitons. Maybe my search method was incorrect but here it goes:

a) If we use a 2007 Yamaha r6 motor with a Motec ECU system, are there any limitations in terms of the engine not functioning without the originial ECU? I called the Yamaha service people and they tell me that there is some sort of integrated intake regulation system on the newer r6's which make it difficult. But I am not sure what is the deal with that.

b) If our team were to design a double chassis system similar to the lotus 88, when determining th side impact force it can sustain, it is the sum of the two chassis or just the inner chassis?

c) Does the engine have to be in the rear?

d) Generally how much carbon does a team buy to build a monocoque, and how much would a team need to be generally to build the body, general figures would be much appreciated, I know there are many variables, but just want to get an estimate for budget sake. The thickness of prepreg carbon we are looking at is 0.27 mm and is measured and sold in meters. is 42 US dollars a meter a reasonable price?

Thanks so much, I apologize ahead of time if these questions have been answered before, I simply could not find the answers.

In addition, if any school is selling motors or parts, please let us know we are in the purchasing stage of our project and any help with parts would be much appreciated.

- Aaron
Korea Advanced Institute of Science And Technology

[HenningO]

I'll have a go at this:

a)
I believe the '07 R6 has a variable intake system which is controlled by a servo (or something similar). This could probably be controlled by a unused output port on the Motec, but would most certainly require some work to get it working.

b)
The Lotus 88, as I understand it had 2 chassis as you say, one aerodynamic and one regular. I don't believe that the aerodynamic one had any structural role besides coping with the aerodynamic loads. But if you design yours to have a structural role, you could probably sum them. But that would require you to submit a structural equivalency form. I'd also recommend asking the judges for their opinion in the matter.

c)
Not really, however most people believe that a racecar have to be RWD and running with motorcycle engines, it's inherently easier to setup a chain driven rear axle. But on the other hand, a FWD usually is easier to drive, but you'll have bigger problems putting the power to the ground.

d)
Try to get the carbon company to sponsor you. We get all our carbon for free (not prepreg though). 42 USD per meter sounds reasonable to me.

As for the amounts required, most monocoques weighs between 15-30 kg (including core material, if used). You can probably get a good estimate by calculating backwards for there.

[RiNaZ]

Aaron, just a tip for the newcomers. Sometimes, when you use the search function, there is an option that says "search current topics only". You need to uncheck that option to be able to search old topics. If you didnt do that, it will only search most recent topics.

second of all, a carbon fiber monocoque chassis is a huge undertaking for a first year team, especially when you plan on doing the master and molds for it. A cut and fold technique similar to LeHigh FSAE (google Lehigh FSAE) is much simpler in my opinion.

What is the weight of your fabric? $42 seems a little bit excessive. Are you buying from a local manufacturer or are you buying it from overseas? If you're tight on budget, working with composites will cost you more than if you were working with metals. So, make sure you know how much money you're willing to spend. In composite, it's the unimportant stuff that will cost you a lot.

[PatClarke]

Hi Aaron, and welcome to the wonderful world of FSAE.
Respectfully, as a first year team in a country without much motorsport culture, I suggest your plans are far too optimistic.

Read the paper I wrote for new teams at this site
www.sae-a.com.au/fsae/downloads/Pat_FSAE_Tech_guide.pdf (http://www.sae-a.com.au/fsae/downloads/Pat_FSAE_Tech_guide.pdf)
This is one of many advice bulletins I have had published on the Australian FSAE site and on the German Formula Student site at www.formulastudent.de (http://www.formulastudent.de)

This is good advice for a new team to design, build and test a car for their first competition. The first competition is the hardest, once you have some idea of what is required, you can evolve your design in whatever way you choose.

What competition do you wish to enter? Possibly the only event you could realistically enter at this stage of the year is the Australian competition at the end of November. If you intend to enter a car in the 2009 season, be aware there are significant rule changes that will make a car built to the 2008 rules ineligible.

As to your specific questions.

It is likely you will have to ditch your Yamaha's entire intake system and replace it with a more suitable one incorporating the restrictor and throttle body as set out in the rules. Many FSAE cars use the Yamaha R6 engine with a MoTeC management system.

The Lotus 88 didn't really have two chassis. It had a structure (the chassis) that carried the engine, cockpit and suspension. It then had a second structure which was an aerodynamic structure that carried wings, bodywork etc which was carried on soft springs. Aero download bottomed out these soft springs allowing the download to be fed directly into the wheels. That car was built to circumvent the F1 rules at that stage, but was never allowed to compete in a Grand Prix. A FSAE/FS car would be required to have the SEF apply to the structural chassis. Aero in FSAE/FS is fundamentally free, so you could build a Lotus 88 type car, but would have to convince the judges about the merits of your design decision.

The engine can be wherever you wish it to be! You can build a FWD or 4WD car if you wish. Again, be prepared to defend your decision before the Judges.

Don't build a Carbon car for your first effort. You are going to make many mistakes and correcting them in a composite chassis is almost impossible without building a new one. A steel tube chassis can be cut and altered as often as needed. Read my recommendations in the paper mentioned above.

Again, welcome to the best student competition in the world and I wish you well in your endeavours

Regards
Pat Clarke

Edit..spelling =]

[Aaron@Kaist]

Thanks so much for all the positive comments. And I've enjoyed your (Pat Clarke's) Technical introduction to the FSAE event. And although I fully agree with the content, it is my job to make sure that my fellow teammates are able to consider all possible options, and make a decision together. This is why I am trying to obtain data concerning as many construction methods as I can. Does anyone have any additional information on the carbon fiber "cut and fold" method? All the data on this forum seems to have been unloaded by the users, especially the posts and pictures by Washington. Also, when will the rule changes be announced for the 2009 competition? Should we hold off on our design until the rules are released? Once again I must thank all the FSAE forum members, previously obtained sound advice from this forum has allowed me to acquire funding, equipment, workshops, and resources for my team, and I really appreciate the help.

sincerely
-Aaron Park

[flavorPacket]

Rules are typically released in late summer as a final draft. You should be aware, however, the rules committee has recently made several significant rules changes in the december-january timeframe. This introduces a lot of stress if parts of your car have already been completed by this point.

[exFSAE]

Better question - why are you thinking of doing a monocoque?

[Aaron@Kaist]

why are we thinking of doing a monocoque? hmm I've seen that question so many times on this forum and I must admit its a very good question. I think it was mentioned earlier in this particular thread that our country wasn't a very developed country in terms of motorsports. Honestly, if we make a monocoque, it'll be one of the first in Korea. We will actually be pioneers in this field in our Country. It'll give companies and related engineers the courage to attempt it in automobiles. But more importantly, I must admit that our structure is slightly different than the regular team. We must capitalize on our scarcity and produce a product (car) that is pushing the technological boundaries of our country, and is, to be frank "good looking" in order for us to feed off the media and use this synergy effect to acquire more funding and support so that our team can really contribute to building to win. Of course the basic idea is the same I guess, but for us we must utilize our school brand name (in our country) and all possible shock factor that differentiates us even from other korean teams. I guess you can see it as our long term plan to win. Also, If the optimal design CAN be produced in a monocoque, I say: teams should attempt it to try and build the skills that they need to produce it some day, of course provided that resources allow it.

-Aaron

[exFSAE]

My feeling.. from 3 intense years of FSAE, and working in motorsport currently..

..is don't just do a monocoque for the sake of doing it (or.. whatever fancy crap you want to use as an example). It's fun to say you want to do a monocoque or flexure a-arms or whatever the hell. But what does it gain?

FSAE in my opinion should be a competition for solid engineering.. rather than a competition for fancy bullshit. Not saying that carbon tubs and all are BS - you run the numbers, and based on that you make the judgement on how to roll. If its the best solution all around, awesome. If not, I lump it into "fancy BS."

I did my own analysis of this thing with our chassis guy, when I was a senior. We came to the conclusion that for this type of car, a tube steel chassis could provide MORE than enough rigidity.. that for $300 (shipped!) you could have all the materials you needed to build one. Going carbon for us would have been an ENORMOUS waste of time and money.

If you can show, with data, that a monocoque of 3500+ ftlb/deg rigidity is necessary, then go for it. Or if at your university its much easier and more practical to do composite layups than welding steel, there's also a reason to go for it.

If you can't prove to yourself one way or the other on what option to take in terms of engineering performance (which is more than likely the case for MOST teams, much less a 1st year!).. then you gotta default to the cheapest, easiest-to-do option.. which in this example I say is the tube steel frame.

Be a pioneer in your country by building a legit, engineered, simple, reliable car that you can drive the hell out of and win with. Not a collection of fancy good looking stuff that falls flat at comp.

[Superfast Matt McCoy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by exFSAE:
My feeling.. from 3 intense years of FSAE, and working in motorsport currently..
</div></BLOCKQUOTE>

Are you Bill Kunst? If not, can you tell us what school you are from and where you currently work. Since your experience has become part of your argument I figured it was pertinent. Mostly I'm just curious.

Back on topic, I agree that if you don't have some good CF facilities, you're probably better off with steel. It takes enough time and effort to get a running car to the competition without adding complications.

[RiNaZ]

Aaron, i understand the temptation of being different than korean teams. And from your post, im guessing that your school is a top notch school on par with how MIT is, in the US. So this might be another reason why you want to keep that standard by pursuing something more complicated. But i honestly think that you have more chance of getting a 'standard' FSAE car running than getting a monocoque done. If you want to have a 'good looking' car, you can still achieve that with a steel frame. Good looking car with steel frames that ive come across are like, University of Florida, Penn State, Auburn University ... and i know a lot ppl really like how Helsinki Poly Univ. from Finland. Believe me, there are other ways of differentiating your team from other korean teams, and you can do that w/out even trying.

Now, if you still wanna build a monocoque, make sure you have enough funding for it. Most of the teams that build carbon monocoque are sponsored by composite companies. So try to see if you can get sponsorship in terms of material. And try to see if you can get a local fiber manufacturer that would sell materials to you instead of buying it from overseas. $42/yard is really expensive in my opinion. I havent bought any fabric for personal use, but at work, we buy in bulk, and it would cost about $4/yard. So ask your local manufacturer that would willing to sell you at a wholesale price.

And if there's a choice, it would be easier to deal with pre-preg than dry fiber. Mostly because, you dont have to buy the resin (you still have to buy some for minor work). If you're new to composite, and doing wet lay-up, ppl tend to overuse the resin, and have a lot of waste. And when you start to realize that you're running low on resin ... you tend to skimp on resin, and that usually leads to dry fiber in your lay-up.

And i suggest that you get some training at your local composite shop so that you'll get enough experience by the time you're done designing your chassis.

[exFSAE]

Doesn't matter where I work or whatever.. maybe I shoulda rephrased that.

Anywhere in industry, as I'm sure other alums here will attest to, the whole "lean" thing is big. Using your time and resources wisely, on the most pertinent things, being very economical, etc.

On the one hand, in college I was far from lean engineering as could be for a while. Wanted to do stuff because it sounded or looked cool. But then you quickly realize that when your team is so small you really have to stop and ask yourself at each point along the way - "Is this actually going to make the car go faster?" - "Is this an efficient use of my time?" etc. Do you want to invest the time and resources to develop a carbon tub chassis, or aero package? Do you have the ability to really do that? Or is it better spent elsewhere?

In racing it just seems the whole 'lean' concept is even more important, because sometimes you are really short on time and people and you gotta make things happen quickly and really be able to prioritize and get at the low hanging fruit first, and anything that will directly impact the next race or season.

There other thing I guess is.. I found it easy early on to fall in the trap of going by what other people do or say. "Claude says to do this" .. "Carroll Smith's book says to always run Pro Ackermann" .. "Oh man look at Cornell's rear end that's a good idea" .. "RMIT is winning with a carbon tub and single cylinder, should we do that?" .. or the absolute worst thing to base anything on, "Well the guys last year did it this way."

And while it's cool to get inspiration and run with ideas.. you gotta really back it down a second and evaluate your decision based on data. I don't care if its UWA, Claude Rouelle, or whoever.. no one source is the gospel. Don't believe in anything until you prove it to yourself. And what works best for one team may not work best for you, or be the best solution at all.

I'll stop rambling now http://fsae.com/groupee_common/emoticons/icon_smile.gif

[screwdriver]

Hi Aron,

Just one remark: The idea of doing stuff differently and beeing the best by using bleeding edge technology and taking risks can massively backfire. I.e you risk to loose valuable support from your sponsors and university, if things go wrong.

Regarding the rules, the current rules alsway have a section at the back with information about upcomming changes.

Also making your car look pretty isn't necessarily about using carbon. You need a good designer who understands the limitations to the shape of the car given by the FSAE rules and people who can put the designer's ideas onto the road.

[vreihen]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Aaron@Kaist:
Does anyone have any additional information on the carbon fiber "cut and fold" method? All the data on this forum seems to have been unloaded by the users, especially the posts and pictures by Washington. </div></BLOCKQUOTE>

A quick search for the word "sandwich" in this forum's archives produced these posts with working pictures of WWU's rather fascinating construction technique:

http://fsae.com/eve/forums/a/tpc/f/125607348/m/31010882...10814711#64410814711 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/31010882711?r=64410814711#64410814711)
http://fsae.com/eve/forums/a/tpc/f/125607348/m/59510034...10354411#46010354411 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/59510034411?r=46010354411#46010354411)

Also, from the "picture is worth a thousand words" department, here is a picture from Lehigh University's web site of them folding one of their recent FSAE cars:

http://www.lehigh.edu/~insae/images/cars/2007/chasisfolding.jpg

It certainly looks easy enough! http://fsae.com/groupee_common/emoticons/icon_smile.gif

Here's some research that you might find interesting, especially for your long-term goals of changing the automobile industry:

http://www.tech.plymouth.ac.uk/sme/r+d/chassis.htm
http://www.tech.plym.ac.uk/sme/acmc/download/chass.pdf

There's certainly a lot of info out there to help your team make the decision about if this is a construction technique they would like to pursue, and there is nobody stopping you from buying some cheap foam/honeycomb core and fiberglass/carbon and making a few test panels to figure out the techniques before making a decision of which way to continue.....

[Aaron@Kaist]

thanks so much for the info, all of you have been a great help and inspiration to us. I have posted all of your comments on our website and we will be discussing these issue for the next few days. It is weird how there are such few posts, but the response time for new posts is super quick haha. I am excited to be a part of FSAE and I will be looking forward to all of your constructive criticism in the future as well. I hope to see you all in person one day, and thank you.

[RiNaZ]

aaron, see the picture in vreihen's post. Do you see the guy holding the heat gun? It's a mundane job with big consequences. Suppose the guy was distracted talking to another guy and forgot that he was holding a heat gun. That heat will melt the spot where he was pointing the heat at. And what you would have is a big air pocket in it, or just simply burn thru it.

And to fix that, judging from my experience working in a school's shop, would take a whole day, provided that you know how to fix it in the first place.

There are a lot of things that i can see where things can go wrong in the picture. Do you see the white lines in the chassis? Those are grooves being cut with a router. It's cut about half way thru. Supposed someone didnt adjust the drill bit right, and cut all the way thru? One more fixing up.

Nobody is stopping in pursuing this route. And i think, sometimes doing a more complicated task might be a great motivation tool for you to get the car done. So, if you're motivate enough to the car the way you want it to be done, i say, go for it. No point of building steel frame if you're not motivated enough to finish it.

[Davo]

I think that if you have the know-how and the resources to build a carbon tub then you could give it a go. It would be cutting edge in Korea, as you say and it would get lots of attention.

Thing is you'd be putting a lot of pressure on yourselves to get it right first time. Imagine if you built up all that hype over there and you didn't get it finished in time. Or even worse, your revolutionary tub gets to the event and breaks. You're going to have a hell of a time getting them sponsors back.

Steel may not be as fancy but it's a much lower risk to your sponsors investment, which is something they like to hear.

[vreihen]

Based on the telephone area code of this company, I'm guessing this a Lehigh chassis in the oven before folding:

http://www.dreamscopes.com/images%26graphics/2007/G7XH6354-sml.jpg

http://www.dreamscopes.com/pages/07/chassis.htm

[James Waltman]

Aaron,
I think all of the pictures are back up.
This topic has some explanation about Cut and Fold:
http://fsae.com/eve/forums/a/tpc/f/125607348/m/31010882...10882711#31010882711 (http://fsae.com/eve/forums/a/tpc/f/125607348/m/31010882711?r=31010882711#31010882711)