Lowest weight 4-cyl?

[Johan_siriusracing]

Hi

Do you guys know what 4cyl car that has the lowest weight in the formula SAE history?

[Johan_siriusracing]

Hi

Do you guys know what 4cyl car that has the lowest weight in the formula SAE history?

[RacingManiac]

Pennstate last year had a 4 cylinder car that weighs something like 369lb or something along that line. And I believe that was the lightest 4 cylinder car. They run 10" wheel. I think someone mentioned also that Waterloo's 13" wheel equipped car is the lightest 4 cylinder car with 13" wheel. I think it was something like 421lb or something.

[KevinD]

don't know for sure, but i would pressume it is the CBR 250RR. i highly doubt there are many other 4 cylinders out there in the 250cc displacement or lighter then this tiny engine.

by switching to the 250, we saved a solid 30 pounds in complete engine package from the CBR600. note that the 250 has a heavier gas tank due to ethanol, and a turbo.

[KevinD]

(p.s. without our aero package our car weighs 405 pounds wet, with 1/3 tank of gas). with the aero package it tipped the scale at 440. we run 13 inch wheels.

last year our car weighed 488 with aero, 13in wheels and cbr600 f4i

[John_Burford]

Kevin

Are the wings articulating this year? From the pictures I seen so far, it doesn't look like the wings are tied to the bellcranks.

And I can't wait to see this car.

Hmmm. Ideas for next year "Cool Can".....

John Burford

[KevinD]

no articulating wings this year. a lot of work has gone into that stuff, but the people involved have all gone away. we are a pretty fresh team with design and we took up quite a bit of changes leaving us with not enough time to fully understand the Aero-in-the-bell cranks. and FYI, i ran some testing last fall on it, and it wasn't working fully as designed. prolly just a slight glitch in the motion ratios but the fact of the matter is we cut weight by 8 pounds in the aero, and are making 100% more downforce up front and 40% more in the rear. pretty good trade off IMO.

the cool can is against the rules technically. of course we considered it. i think when Craig Henry came up with that idea he got it in there before the rules specifically called it out. additionally, the ethanol doesn't quite have the same cooling effect as the methanol did.

[John_Burford]

Where does the rules say it is illegal? There were a few gray areas, Yes. But I don't recall it being outlawed.

96 and 97 had the cool can, and 98 was going to but didn't only because of limited time to design a light weight heat exchanger.

Has anyone looked at the 98 senoir design report on "Cool can Optimization" and updated its finding for Ethanol?

John Burford

[Scott Wordley]

John, before I hijack the thread by asking KevinD about his aero, I thought the more appropriate question might be:

"What is the lightest 4cyl car that has finished all events?"

Kevin, a few questions:
- Are you saying that your wings are now rigidly mounted to the chassis? Any reasons for this apart from the fact that its easy and slightly lighter?

- How did you increase downforce so much? More wing area or better profiles?

- How did you measure this increase in downforce? CFD, wind tunnel or on-track?

- Did you have to increase your spring rates much to keep the front wing off the ground now that its making double the downforce and is rigidly mounted?

Did Dr Bob show you those aero papers from detroit? If so what did you think?

Good luck at comp, hanging to see you guys finish enduro.

Scott

[KevinD]

weird... i swear i read a rule stating that you could not alter the air before the restrictor in any way (pressure/temp).

[Marshall Grice]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> - How did you increase downforce so much? More wing area or better profiles?
</div></BLOCKQUOTE>

my first guess is going to be from their HUGE tunnels. I'd like to know more of course.

[KevinD]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
"What is the lightest 4cyl car that has finished all events?"
</div></BLOCKQUOTE>

burn!!!!!

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Kevin, a few questions:
- Are you saying that your wings are now rigidly mounted to the chassis? Any reasons for this apart from the fact that its easy and slightly lighter?
</div></BLOCKQUOTE>

yes they are rigidly mounted to the chassis. there werea number of reasons. this was a huge debate on the team for quite some time. obviously having unsprung aero has its advantages. but honestly you need to pick and choose where your team is going to spend time for development. it was my decision to not spend the time making it work this year. i'm certain the change will not hurt us in design because we did quite a bit to make sure it was the right choice.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
- How did you increase downforce so much? More wing area or better profiles?
</div></BLOCKQUOTE>

much much much more wing area. better aspect ratios, cleaner air due to high rear wing (better aero balance), the front wing is enormous compared to last year. the wing profiles have changed, and the spacings are much more aggressive. AOA was better optimized as well for the static wings.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
- How did you measure this increase in downforce? CFD, wind tunnel or on-track?
</div></BLOCKQUOTE>

all three. the on track was the best indicator, but it showed what CFD predicted.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
- Did you have to increase your spring rates much to keep the front wing off the ground now that its making double the downforce and is rigidly mounted?
</div></BLOCKQUOTE>

an unfortunate side effect. yes we had to greatly increase the spring rates. ironically though, the car actually handles better then before. although i will not attribute this to the increased spring rates because nearly everything else has changed as well (suspension geometry, mass of the car, size of the car, CG height, and wheel base).

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Did Dr Bob show you those aero papers from detroit? If so what did you think?
</div></BLOCKQUOTE>

i have a bunch of aero papers Dr. Woods gave me. i can't recall if any of them were from you though. i have heard about your paper(s) and would like to read it though. honestly you would have to talk to our aero guy though. hes the one in charge of the wings... send me a PM and i'll give you his contact if you would like to talk to him.

oh, and usually the unsuspended aero design would have been left up to the aero guy to work out, but at the beginning of the year i was chief engineer and our aero guy was absent for personal issues. that is one of the reasons that drove my decision to get rid of the aero-in-the-bellcranks. sense then he has returned and taken over his duties again.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Good luck at comp, hanging to see you guys finish enduro.

Scott </div></BLOCKQUOTE>

thanks, and i really hope we finish too!!!

[jaimin]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by KevinD:
weird... i swear i read a rule stating that you could not alter the air before the restrictor in any way (pressure/temp). </div></BLOCKQUOTE>

you saw one commenting on the temp of fuel. dunno one about air. that would fall under intercoolers, which are nessesary(sp) for running turbo or sc engines effectively. oh and the rule there is air to air intercoolers only.

3.5.2.1 Fuel Temp Changes -Prohibited
The temperature of fuel introduced into the fuel system may not be changed with the intent to improve calculated fuel economy.

Is anyone from UTA gonna be in Romeo? I want to see more of this 440 lb car.

EDIT. more thoughts on the discussion.

[KevinD]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by jaimin:

you saw one commenting on the temp of fuel. dunno one about air. that would fall under intercoolers, which are nessesary(sp) for running turbo or sc engines effectively. oh and the rule there is air to air intercoolers only.

Is anyone from UTA gonna be in Romeo? I want to see more of this 440 lb car.
</div></BLOCKQUOTE>

we have a turbo and no intercooler, so i wouldn't really call it necessary... and i can argue that it is very effective doing it the way we are http://fsae.com/groupee_common/emoticons/icon_wink.gif

as far as i know, there will not be anyone in detroit. i know the car wont be there, we are going to california instead. if you want to see the car in action without going to cali, you are not to far from here, so check out the texas autocross weekend. already sounds like there will be a huge turnout.

[buddy]

Hey John,

I ran some heating value/ restrictor flow rate calc's and in terms of heating values the ethanol absolutely needs the "can" (basing performance purely on heating values). I did this the year ethanol became available.

buddy

[buddy]

Johan,

to answer the lightest car question...

Ill. Urbana-Champ. built a sub-400# car around 1999. It had a turbo 600 Honda with ~80 hp. It was very fast in the acceleration event but as I recall had a mechanical failure. The car had monoshock suspension front/rear with single-shear mounted a-arms.

buddy

[John_Burford]

Buddy

The Ill. Urbana team confessed the following year that the car went to the design scales without 20-25 lbs of parts and fluids. But in 94-95 they had the Sidewinder (beam front suspension and solid axle rear). It was simple, durable, and wicked fast in a line, but couldn't turn. After two competitions and a year of driver training use, it showed up at the 96 SCCA nationals still goin strong.

Ethanol was introduced a few years back 2001 or 2002. Thankfully the ethanol resictor diameter was sized appropriately (good job Michael Royce). Althrough the 90's the methanol cars were handicapped by 10 to 15 precent less horsepower than the gasoline cars.

John Burford

[John_Burford]

Buddy

I misread your messaage. When you did the calculaitons how much of the total fuel did you include 20% or 100%?

John Burford

[John_Burford]

KevinD

I sent you a PM.