Not quite F1, but almost (FSAE project)

[Smeerak]

Hey guys, need some professional advice here.

My school is building a Formula SAE race car. We're in the initial stages of planning and design and would like to know if it's worth it to have front and/or read wings on the car.

Here are some specs from the SAE website

Top Speed - Est 115Km/h

Avg Speed - Est 48-57Km/h

Thanks a lot for the help, I'm sure that I'll be picking your brains in the months to come.

-Kareem

[akbar21881]

wow...that would be bloody interesting.where is your school?
is the estimated 115km/h is calculated including the wing efect? but at average speed of less than 50km/h(I assume there are a lot of slow corner) I dont think the wing will work though

[KeithYoung]

It is a good question, one thing to keep in mind is the track is designed to keep you under 75mph, the main thing to focus on in such a car is the mechanical handling, then afterward worry about aero. With the cars averaging such low speeds and having so many turns of so many types, you need to focus on low CG and brilliant suspension and steering geometry. I have seen teams with wings and they looked like drag hogs, they were high on the car raising the CG, and their affectivenes is rather small due to the design of the track. I suggest worrying about chassis stiffness and all the geometries before even thinking about aero, maybe after you develope your car you will see you can support or will need a little aero download, but untill then i dont suggest planning around aero. Look at past champs, few have extravigant aero setups-simple wins in FSAE!

[akbar21881]

what is SAE website? can anyone tell me? I'm very interested.Pity that Bristol uni is not involved in this

[NickT]

Race Tech magazine has done a lot of articles on SAE. Some of the other guys may be able to tell you about Race Car Engineering and other possible sources of information.

Cheers

[Monstrobolaxa]

I'm in aeronautical engineering and as a end of degree project I'm planning dto design a FSAE/F.Student car....and on thing I'e found while searching the web for info about the cars....was a paper by one of the elements of the jury that said: "keep it simple"....and "there is no point in putting wings on the cars because of the low speed they reach"......well.l...in straight line.....they reach high speeds....but at the speed you reach during the skip pad test and the track endurance test (during a corner) the wings wont be working almost anything....the FSAE cars usually curb at the max at 75 km/h.....which is relativly low speed....so the wings in a SAE car will only bring extra weight....and take points for 2 or 3 categories....such as: simplicity and the category that states if the car is easy and cheap to build....

[Asphodel]

Wings on FSAE cars have a advantage. This year at the FSAE-Australia competition, The Monash University FSAE car was 1-2 seconds faster than any other cars on the track at the time. There were problems with reliability. Carrol Smith thought that a car with downforce could dominate the FSAE competition

Read Competition Car Downforce: A Practical Guide as a good starter for design.
Check out the forum at http://www.fsae.com/

Cars with aero packages:
http://www-personal.monash.edu.au/~fsae/
http://www.csupomona.edu/%7Efsae/
http://www.formularpi.com/
http://fsae.uta.edu/

[Smeerak]

Wings on FSAE cars have a advantage. This year at the FSAE-Australia competition, The Monash University FSAE car was 1-2 seconds faster than any other cars on the track at the time. There were problems with reliability. Carrol Smith thought that a car with downforce could dominate the FSAE competition

Read Competition Car Downforce: A Practical Guide as a good starter for design.
Check out the forum at http://www.fsae.com/

Cars with aero packages:
http://www-personal.monash.edu.au/~fsae/
http://www.csupomona.edu/%7Efsae/
http://www.formularpi.com/
http://fsae.uta.edu/

Thanks man, I will defeinitely take a look at those sites. I think since we're a fledgling team we're really going to concentrate on power extraction fronm the engine, but there comes a time in every engineers life when, yes, you must face the 'dreaded' aero design !

cheers and I'll kee you lads/laddies posted

[mark hester]

monash won the one lap autocross but only by .2 sec and the car in second (ours) was powered by a 450 single cylinder engine with no aero just a great chassis, this shows the diversity of fsae and the fact that two cars from oposite ends of the design spectrum can be so close on track.

Both us (RMIT) and monash are preparing our cars to compete at formula student in july which is the first time aus teams have travelled over, cant wait!
ps we set the fastest time in the enduro by 1 sec
http://www.fsae.rmit.edu.au

[Monstrobolaxa]

Like I mention previously...I found the link to the article of the Formula Student Chief Design Judge, where he stats that suspension layout is more important in the F. Student. Another thing is the idea of the F. Student is to design a car that is Marketable and that costs under $25000 US....well using wings will bring up the cost of construction, will add weight and the adventage that it brings might not be as much as the disadvantages........you can lose points in the design/market parametres and not gain the lost points in the dynamic categories.

I'm not saying they don't work...I'm just saying in a F.Student kind of aproach they might not give you the edge......if I built one for personal use at I'd include the wings.....but in a F.Student way i wouldn't....it would penalise the team in the marketability/costs parametre....and the time lost due to the dseign of the wings can be used in a further detailed suspension design...which might give you the edge...that the wings might not give.

The famous Carrol Smith, previous judge, used to say that aero was importante......well....2 diferent engineers....one from the old school and another from the new school......i agree with both.....but for me suspension......has a slight advantage (in F. Student terms).....but it also depends on the circuit that is used.....I say a video of the F. Student and the race was held at very slow circuit that basicly consisted of chicanes....and slow hairpins.

the link:

http://www.imeche.org.uk/formulastudent ... 202003.pdf

[Shoeless23]

I am a team leader from the University of Texas at Arlington(http://fsae.uta.edu/) We have been using wings in various forms since 2001. In 2001 the wings were chassis mounted. In 02 and 03 the wings were attatched to an undertray and connected to the car at the outer lower a-arms to get aero forces directly into the tire. Both of these systems created problems: the '01 car has a terribly stiff ride to counteract the forces from the wings at high speeds and the '02/03 cars were overweight because of the noncompliant undertray and the ride height(most importantly cg) was raised. The new UTA package is not currently on that website but uses an innovative way for the wings to attach to the inboard susp belcrank. That way we could get back to a normal cg and lost 35 lbs of undertray weight.
I would like to add that this is a very experienced team and have spent many hours in windtunnels and several thesis written on fluent analysis. We have optimized our suspension over the past 20 years and have realized there is a definate advantage to our wing package (38% of the car's weight in df at 85km/h) which allows for .2-.3 lateral g increase. At local autocrosses were are seeing lateral g's in the 1.6-1.9 range, so we are still attaining large amount of mechanical grip, which is what the focus should be of a new team. Also, low weight and cg are critical whether or not you have wings. The more the car weighs the less percentage of downforce you have. Our car "wet" with wings and undertray weighed in at 488 lbs. which just gets it under the unsaid "500lb." rule for design finals.

[RacingManiac]

Yep, UTA is definitely one of the oldest and best performing team out there. So far in my 2 years of competition for University of Toronto I have made it a point to see the UTA car because their car is usually a looker and extremely fast.

I think for FSAE/F. Student/FSAE-A the aero aspect depends largely on the track layout. I've heard that FSAE-A's track over the years have been faster than the FSAE track in Detroit where some corners were taken at higher speed. While before 2004 Detroit's track were usually a lot tighter. And Formula Student I think is even tighter which is why Monash's car is not as fast as I think it would have been at England when we saw them this past July. 2004's Detroit track though seems to be a lot more open and if this is the trend then it may play into the hands of those who run aero. We tried aero in 2003 but that was the only year UofT have tried that and packaging may not have been ideal, but it does add a good 20-30lb to the car.

[alex1015]

Just got back from the Formula SAE contest at VIR. I have plenty of pictures. Wings for all intensive purposes are useless. They raise the CG, add drag and weight. At eh speeds SAE likes to keep the cars at the down force just isn't produced. From just a technical exercise prospective it is interesting though a bit useless.

You have to keep the goal in mind you aren't designed a race car but rather something to be as successful as possible under the regulations. One team fielded a CVT which is interesting technically, but predominantly not worth it. We run mainly in second gear and the courses are twisty enough so that it almost exclusively 2nd with occasionally a 3rd gear straight, this means a CVT shiftless advantages is pretty well lost.

EDIT: WHOA, sorry to bump a super old thread, I didn't realize.

[AeroGT3]

My uni has been working at a wing package for the last 1.5-2 years. The CFD that has gone into our package is extremely advanced and ahead of what most actual companies do . . . I can confirm this from interviews and internships I've had.

We expect to have the lightest car this year and the highest downforce . . . without the huge tacky wings. I think we will shake things up and change the views on aero and also the aero norm of big huge constant cross section wings.

If you are very good at aero and CFD, Aero can be a huge performance gain in FSAE.

Alex: I don't want to give off specific numbers yet, but our wings are FAR from useless. Aero can be worth it if you do it proper rather than using the same old, ineffective wing sections with no twist and huge surface area.

Our wings provide more performance per dollar than the move to a carbon chassis does.

[Jersey Tom]

More advanced than 'most actual companies' ? What does that even mean? I'm sure its 'more advanced' than CFD McDonalds does.. but I'd imagine its nowhere near that of a Formula 1 team.

CFD is nice but it isn't hard test data.

How consistent are your drivers? Are they able to put down competitive laps and be within 0.2 sec of each other?

How many tenths faster do you run with aero package than without, in autocross? Is the difference definite given the driver consistency?

Does it make any difference in skidpad times?

How much slower does it make an acceleration run?

That's the only stuff I'd be interested in. Or if not that, what validation and verification have you performed? In a rolling wind tunnel, how well would your CFD match to real life? In the straight ahead position? Does it capture yaw sensitivity? Pitch sensitivity?

What uni are you with? I'll likely be around at competition in Detroit.