Traction Control

[karter]

I just finished watching "Trading Paint" on Speed Vision, Jeff Gordon drove Juan Montoya's Williams and Juan drove Jeff's Chevorlet on the road course at Indy. The facinating thing was Jeff's coments about the traction control and how it affected handeling, particulary oversteer comming off the corners. In NASCAR talk, the F1 car was loose so he just hammered the throttle and the traction control stuck it down and "boggitie boggitie", off it goes...... I'm wondering if anyone has messed with traction control and antisquat. I'm guessing that if you have the rear suspension set up with a large amount of antisquat, say near 100% and traction control, the car could be a rocket off the corners.

[karter]

I just finished watching "Trading Paint" on Speed Vision, Jeff Gordon drove Juan Montoya's Williams and Juan drove Jeff's Chevorlet on the road course at Indy. The facinating thing was Jeff's coments about the traction control and how it affected handeling, particulary oversteer comming off the corners. In NASCAR talk, the F1 car was loose so he just hammered the throttle and the traction control stuck it down and "boggitie boggitie", off it goes...... I'm wondering if anyone has messed with traction control and antisquat. I'm guessing that if you have the rear suspension set up with a large amount of antisquat, say near 100% and traction control, the car could be a rocket off the corners.

[Patrick W. Crane]

That'd be some pretty nifty looking suspension http://fsae.com/groupee_common/emoticons/icon_wink.gif Plus, squat is good for acceleration - gets lots of traction onto those rear tires.

- Patrick W. Crane
University of Victoria
Engine Team/Testing UV04
quote: "i do not approve of racing near concrete walls"
- Speaker at Team Captain's meeting, Detroit 2003.

[Denny Trimble]

Class, can anyone tell me what happens to your rear roll stiffness on corner exit if you have 100% anti-squat?

University of Washington Formula SAE ('98, '99, '03)

[karter]

Hmmmmm musta' fallen to sleep again, I thought there was a problem with bumpsteer associated with anti dive, anti squat ,,,,, how would roll stifness be affected??

[clausen]

My understanding is that antisquat makes the rear spring rate effectively stiffer under acceleration, so I think it would be a bad thing for powering out of corners. I think its good for launches, as in the transitional period just after you dump the clutch, the suspension is more strongly resisting the squat movement of the chassis, so in that transistion the normal force on the tyre increases quicker, therefore more bite.
After that transition, in a straight line, it doesnt make any real difference. The weight transfer is completely dictated by the CofG height and the wheelbase. The only difference it does make is to the angle that hte chassis maks with the road. Important for aero, and a big reason F1 cars have run it. I have also heard that in years past F1 cars have run antisquat to reduce the bad power understeer problems that have come up now and then. (this is 20 odd years ago)
I think that possibly some pro-squat might work for corner exit.

[MercerFSAE C. Burch]

Remember that on corner exit, as the power is being put down to that outside rear tire, you want to keep it almost at 0 degrees camber with respect to the ground. Large amounts of squat would put loads of negative camber into the tire, which would be bad for coming off of the corner. So a little anti-squat might help, in my opinion, to keep the loaded wheel upright. It really depends on how much chassis roll there is at the rear, what the camber curve is, and what the initial rear camber is.

The opinions vary in all the reading I've done. What is appropriate for one car might be the opposite for another car. It might turn out that there is so much roll in the chassis that squatting at the rear will put just the right amount of camber in the tire. It is an area where an anti-roll bar would come in really handy for fine-tuning.

Chris
Mercer University - Drive!
Coming to an Auto-X track near you, May 2004!

[Sam]

You can rig up traction control with the motec. Uni of Tassie did it at the 2002 aust comp. they had a lot of trouble with it though. basically, you hook some hall effect sensors on the front/rear wheels. motec has a traction control system on it. i believe it needs to be enabled though (extra cash). it will simply cut ignition to a certain level depending on wheelspin i think.

Sam Graham
Engine Group Leader 2003
UQ Racing