View Single Post
Old 06-07-2016, 12:31 PM   #3972
GSpeed
 
GSpeed's Avatar
 
Join Date: Apr 2015
Drives: 2015 BRZ
Location: Motorsport Ranch, TX
Posts: 619
Thanks: 227
Thanked 1,181 Times in 362 Posts
Mentioned: 30 Post(s)
Tagged: 1 Thread(s)
Quote:
Originally Posted by jarnojvv View Post
Hi Guys,

I have a relatively standard 86, only changed to Pilot Sports and a couple of small things. Doing camber bolts when I'm home again in a couple of weeks.


I would like to understand the difference between front and rear toe out (a) under braking, (b) turn in, (c) steady state cornering & (d) corner exit/power out.


If you are also on standard suspension feel free to post your alignment!


Thanks!
I don't have bump steer numbers for the car yet, so I'll have to answer in general terms. Bump steer on a road racing car is extremely important, and often overlooked. A good shop will spend several hours on one car getting less than 0.01" per 1" of suspension movement. Bump steer behavior can significantly affect the following tendencies if it's too much.

Front toe out is going to most significantly affect turn-in. The car will feel much more responsive since the inboard tire will develop higher slip angles sooner and "pull" the car into the corner, if that makes sense.

Rear toe out is going to be a bad thing, generally speaking. It will make the car very darty and unstable. It'll want to come around under hard braking, especially trail braking. It'll seem squirmy under hard acceleration. We usually aim for 0 to 1/16" total toe in for the rear.

Keep in mind you can't change anything in a suspension setup without affecting other things to some degree, but those are the most significant effects.

Jake
GSpeed is offline   Reply With Quote
The Following User Says Thank You to GSpeed For This Useful Post:
jarnojvv (06-07-2016)