minimize understeer

[tunerdoc]

I would like to know how to minimize the understeer on a 1997 GST Spyder.
I have lower the car 1" and put on a strut tower bar. Gone to 18" tires.
Wht would be next?
If I change the caster camber how do I find the correct spec for the front end shop?

Thank You

Doc

 

[cuttheduck]

- higher spring rates in the rear
- Adjustable shocks set stiffer in the rear, softer up front
- Rm rear sway bar
- about half as much rear negative camber as the front

 

[PaulPDX]

Tire pressure. Slight changes in tire pressure make significant differences. Much easier and cheaper than changing springs... problem is you have to find a good compromise between contact patch and handling... ie safety and performance, as with anything performance oriented mod. Negative 2 camber will help turning... but not so great for tire wear. You just have to experiment and find what works best for you. 2 drivers can get different results from the same setup. There is no fix-all silver bullet. Go to the track and experiment... just like playing GranTourismo on the PS2.

 

[ACM]

Exactly what spec is your front suspension ?

Typical 2G setups have the car into the bumpstops under mild lateral G. When this happens the front spring rate rapidly rises to infinity and the resultant understeer cannot be reduced without directly addressing this issue. No amount of tyre pressure or rear suspension tweaking will correct the problem globally.

Check your front suspension travel by puttnig a ZipTie around the front damper shafts, go play on some 'good' corners and check where your zipTies end up - I'm betting they're buried up inside the bumpstops.

Charles.

 

[PaulPDX]

Typical 2G setups have the car into the bumpstops under mild lateral G.

So it does. Wouldn't increasing spring rates limit the chances of running out of travel? Changing springs and shocks are the obvious things to do anyway. After that... couldn't the handling be fine tuned with varying tire pressure? Increase spring rates in the front so that it can handling more lateral Gs without bottoming and increase the rear spring rates to overcome the understeer, etc. Ride quality will be compromised obviously.

I don't think the 18" tires will make any difference at all. 18s are more for looks. If anything the increased rotational weight will retard turn-in. Whether the result is significant or not... who knows, depends on how heavy the wheel and tire combo is.

Doesn't the VFAQ have some camber information?

 

[DSMeclipse4G63]

235 tires in front and 185 in the rear...In order to minimize understeer you need the rear to give out before the front does. For real life with same tires in front and back do the above, but if you wanna save money use my idea
Andrew