mountainbiker2

C5 Corvette. Autocross.

Front toe? My understanding is that toe out in the front makes quicker turn in. What about the rest of the turn? The car might turn in quicker, but what about grip in the middle of the turn and exit? Can't I just turn the steering wheel faster? I had a guy tell me that 1/16" toe in would make the car grip much better in sweepers then toe out. This same guy gets top time of the day quite often. Not a Corvette though.

Rear Toe? Toe in on the rear to get better grip on exit? What about the rest of the corner? I believe it creates understeer more.

Thanks,

Steve A.

fatbillybob

look up akerman angle and it will explain whys of front toe out. My understanding on rear toe is that the toe set is ment to control rear steering as the car goes through its full suspension travel. note on the C5Z06 rear toe is about zero yet on an NSX it is huge at about 1/4"-3/16". The reason is you don't want rear steering as the suspension changes and you want to err on understeer of the chassis for safety. In the the C5 as the susoension changes the rear toe almost does not change at all therefore zero toe in the rear makes sense because suspension travel does not induce rear steering. In the NSX you need the large toe in the rear toavoid rear steering and the negative was quickly wearing tires in the rear.

BEZ06

Take a look at David Farmer's great site:

http://davidfarmerstuff.com


Scroll down and click on "Why Toe Out", and check out the other links for some good info about alignments: "alignment guide", "Camber Plates", and "Suspension Setup".

Bob

sperkins

Definatetly toe out front and toe in rear. One of the tracks we run in the southeast is like a really big autocross course. I run a lot of toe in on the rear and it's fast. Rear toe is more crucial than front in my opinion on tracks like that. Rear tire wear is minimal as well.

bobmoore2

Steve,

You have been asking several questions about suspensions and handling lately. Have you ever read this book? You'll probably find the answers in there, plus lots of things you never even thought of.

How to make your car handle - Fred Puhn

-- Bob

drivinhard

You'll get 1/16" of difference just from having 200 lb driver weight simulated in the car, or not.

Solofast

Rear wheel toe in provides "roll understeer". That is, as the car rolls it steers the tire that the load is increasing on towards the inside of the corner. This increases stability so you have to steer more into the corner as the car rolls to maintain your line.

What happens is that the car yaws first, then generates lateral g in the rear tires, and then the car rolls. In an autocross you don't generally have as much steady state cornering. You have more transients and you need the response there. Toe in in the back prevents the overshoot that would happen as it gives you more understeer later in the cornering process.

What seems to work is some toe out in the front to get the car to turn in quickly, but some toe in in the rear to maintain stability.

You really can't talk about transient response without including shocks into the equation. While toe is important, you need to fine tune transient response with shocks. That way you get the car to turn in quickly, build g quickly and then maintain a high lateral g (roll stiffness distribution, tire grip and camber effects predominate here).

froggy47

lurk

TriplBlk

rustyguns

damn those NSX's ! They are quick little devils!