Too much understeer

[dza00]

So I have been to the track once with my Z (~2 years old now) when it was bone stock. Since then, I have put on an endless function xs suspension, a arms, rear camber arms, a stoptech brake kit, and 19's (unfortunately... rear brakes are too big ). My tire sizes are 245/35/19 F and 275/35/19 R and the suspension is set at 2 in the front and 4 in the rear (out of 6).

I'm going to get an alignment this weekend. What settings will reduce my understeer? It is even plagueing my everyday driving. Also, my car is about 1" lower than stock. Should i change the ride height or suspension settings? How about sways?

Thanks to all in advance for the help

[Steve_03]

I know nothing but I'm bored so maybe this will help. Its stolen from an M3 site, but maybe it will get you started for a quickie.


TO INCREASE UNDERSTEER || TO INCREASE OVERSTEER

Front Tire Pressure: Lower || Higher
Rear Tire Pressure: Higher || Lower
Front Tire Width: Smaller || Larger
Rear Tire Width: Larger || Smaller
Front Camber: More Positive || More Negative
Rear Camber: More Negative || More Positive
Front Springs: Stiffer || Softer
Rear Springs: Softer || Stiffer
Front Anti-Sway Bar: Stiffer || Softer
Rear Anti-Sway Bar: Softer || Stiffer
Toe-In: Increase || Decrease Ed.



http://member.rivernet.com.au/btaylo...ineTuning.html

[plumpzz]

a more positive rear camber increased oversteer? You'd figure it'd be the other way around.

[Steve_03]

Positive camber would bring the bottoms of the tires closer together in the rear. Which would cause the back to kick out sooner (oversteer).

[Steve_03]

This article gives a good explanation of camber,toe and caster.

http://www.ozebiz.com.au/racetech/theory/align.html


Wikipedia also gives a decentoverview of suspension things.

http://en.wikipedia.org/wiki/Car_han... fect_handling

[12AutoX]

Wider front tires, stickier tires, stiffer swaybars.

[Fluid1]

The only thing you should change is your tire size. If you run the same size tires on all 4 corners, your problem will go away.

[Motormouth]

I am surprised you have this problem. sounds like a bad alignment.

check your front camber settings, rear toe and camber settings...

if you put swaybars on that is most likely your culprit.

if it was your selection of tire size, bumping up the front size will help.

[Kolia]

Originally Posted by dza00

... My tire sizes are 245/35/19 F and 275/35/19 R and the ....

What did you expect with skinny front tires ?!?!

No amount of alignement will cure the steady state understeer. You'd end up with insane front camber and the car won't brake very well.

Go wider in the front, or slimer on the rear.

[Stack]

This is the requisite post telling you that you did it all backwards. You're now stuck with the task of chasing your problem down after adding so much stuff as to make it impossible to pinpoint the cause of the effect.

But, whats done is done... you could undo it all, but that is unrealistic

Start with the alignment, don't do anything else except maybe widen the front tires (but my guess is that might require new front wheels).

Are you asking for street use or track use?

[dza00]

Thanks for all the responses.

I'm looking for a combination of both street and track use. I originally had 18x9.5's running 255/40/18 's on 4 corners but i was forced to buy 19's quickly because my rear stoptechs were rubbing the 18's. so now i have 19x9.5's F and 19x10.5's R. I think next tire change i'm going 265/35/19 F and 285/35/19 R. Could I go 275/35/19 F perhaps?