Reply to "twitchy, nervous steering on unsmooth roads"

Ron,
The feeling I get is that you talking about tire pressure as being the tool for setting the balance of car up. The balance of the car should be balanced with swaybars, springs and schocks. NOT, tire pressure.

You mention your alignment setting, which is Ok. The rake of the car is 1,5" lower front, which is a bit much.
I don�t get your sidewall number right. A sidewall of 2,5" + 15" makes a 20" diameter tire!!!

We cannot play around with tire pressure difference from 8 to 32 psi. Second, I don�t know what tire you use. Other Panteras does probably have other tires that don�t compare.
A tire has a narrow range of pressure. And we should look at the tread temperature with a tire temp gauge to sort out tire pressure.

You have a good balance car, but at the same time a car that may overheat the tires at sustained driving. This show that we can�t play this much with tire pressure.
A bigger contact patch takes another tire.

As fare as comfort is concerned, we better leave thing like that when discussing sportscar set up.

A front airdam has little effect on car balance.

Pantera has a large scrub radius that creates road input to the steering wheel.
A-arm rebuild takes care of this. This will not change the driving stability, but lessen the input to the steering wheel.

Q-1.
A Pantera is about 42-58% weight distribution.

Q-2.
I have been playing with anything on the car,
and don�t recommend playing with tire pressure.
If the car doesn�t handle road irregularities well, then we should work with shock absorbers.

Q-3.
Checking tire temperature will automatically compensate inflation pressure for car weight.

Q-4.
The cornering balance should be performed with swaybars, not tire pressure. Put the widest possible tire on the car and do the balance with swaybars and springs. Then set the reaction with shocks.
The dampening properties of the tires are outside our control. We should have the movement where we can adjust it.
Goran Malmberg