I've been seeing more symptoms of oversteer under hard cornering in the Z. Suspension is stock. Would the (heavy) replica chrome Z wheels with 265's and 295's cause this? Would sways be playing into this? I have a set of featherlights on the way and would like to get all this sorted out at the same time. Thanks guys

 

Could be old hard tires in back, could also be tire pressures.

What are you running? How old are your tires?

 

How are you experiencing this exactly? On the street?

More the likely the tire pressures or the tires themselves.

I found the car had to be pushed VERY hard on the track to oversteer.

 

^^^^^What he said^^^^^

I think you need to spend money on tires before you touch the suspension...

 

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Definitions:

"Understeer", also known as "push", and "dammit, why won't the car turn?", happens when a vehicle doesn't turn as quickly as the angle of the front wheels would suggest. Turning the steering wheel further just makes the tires slip more. An understeering vehicle wants to point to the outside of a turn, plowing ahead instead of where the wheels are aimed.

"Oversteer", AKA "loose", or "OH S*&T!", is when the vehicle wants to turn too far, with the back end sliding around and, in extreme cases, trying to pass the front. An oversteering vehicle feels like it's about to spin, and frequently does if the driver isn't skilled enough to "catch" it.

An easy way to remember the difference is that Understeer is when you see what you're about to hit through the windshield, but Oversteer means you see it in the mirrors...
source: http://www.miracerros.com/mustang/sway3.htm
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OK tires are TOO OLD or HARD. and you need:

1- new softer tires,
2-a better alignment
3- Lots more seat time and
4 maybe bigger sway bars.

 

Where is the oversteer? Is it on corner entry, mid-corner, corner exit, or a combination? There are different remedies for each. Try to break down the cornering ability of the car into those three segments.

Assuming that the tires aren't too aged and the pressures are consistent with previous, if this is something that's shown up over time, I would suspect that the alignment has shifted.

 

Guys - thanks for all the replies I should have not been posting obviously since my issue is NOT oversteer but UNDERSTEER. I've noticed it on 2 occasions: 1 was a sharp 90 to the right while downhill (I had just come off the brakes and wasn't ready to get on the go pedal due to corner conditions - possibly the lack of acceleration / more front end weight contributed here). The other was hard acceleration through a sharp left hand corner. I'll take the corner again to better understand at what point it occured.

Tires have plenty of tread and are Toyo T1R but were purchased with the car and I'll have to check their DOB as well as tire pressure.

I'm not doing coilovers to solve the problem but mainly for lowering the car a bit.

 

If the car's already been lowered, make sure that it's not too low. If it's too low, under braking the shocks may be on the bump stops, thus effectively an infinite front spring rate and thus understeer.

 

Tread depth has nothing to do with traction. tread depth is for rain water run off.

traction has to do with age of the Tire. and how long or how hot / warm the tire is.

 

What kind of driver are you? If you lift off the brakes at the wrong time, the weight transfer to the rear and the car won't turn very good. You should trail brake into the corner. If you get on the gas real hard, it also transfers weight to the rear. This making poor steering again.

Steve A.

 

Oversteer scares the passenger. Understeer scares the driver.



The C5 can go from understeer to oversteer pretty easily with a little bit of throttle input. It's best practiced on the track and not on public streets.

 

When i first bought my C5 Z06 several years ago, coming from many awd cars, i noticed that these cars have an amazing chassis but do get tail happy with the traction control turned completely off. Originally being on brand new Firestone Firehawks first impressional grip was fine. You could really feel the cars corning ability through the suspension and chassis under light loads of throttle around corners. However, once confidence sets in it becomes quickly apparent these cars have a breaking point that comes without warning and suddenly snaps out on you. Again coming from awd cars i was used to applying throttle hard and early. After some getting used to this and accepting the "whens it gonna bite me paranoia" i decided to A) Get better tires, and B) Do some suspension upgrades. Sitting on Nitto 555r2's and running Bilstein sports with Johny O sways, lowered a 1/4 stock leafs corner balanced the car is a whole other car. I can literally hammer the damn throttle before the apex and make the tires squeal with grip at will. It has become very neutral and feels like a equal combination of the front and rear slipping when its pushed to the limit of the tires which let me know its coming far before the breaking point. If you do some mild suspension work with some gripping tires you will not believe what these cars can do. Upgrade the brakes too and you will be in driving heaven.

 

The T1R's are about 2 years old and running 30psi all around.