993 Suspension questions

[rgreeny]

I have a 96 coupe that I have just put PSS10 and TRG sways front and rear. I am driving DEs and need to know when to adjust shocks either tighter or looser (front or rear) and when to adjust the sways (front and rear).

I set the shocks at 7-fronts, 9- rear and the sways are set in the middle hole for the track.

I am looking for another DE driver or racer to help me.

I have try to find info on line, but have not had good results.

Thanx in advance.

Rob

[38D]

You are not going to get very good info, as there are many other variables including spring rate, tires, bushing material/condition, ride height, alignment, etc. Your best bet is to find a very good instructor with racing & setup experience, and ask them to drive the car & help adjust the setup.

[Flieger]

Attack each variable in a stepwise procedure.

First, set the sway bars to full soft (or remove them)

Set dampers full soft.

Go out and do a few laps to get base line numbers. The car may feel "wallowy". This is because the springs are overpowering the damper and are oscilating like a tuning fork.

Stiffen the dampers 2 clicks each time until your times fall off. The car will feel too stiff and will fly/bounce over curbs and "jack down" and "jack up" on the springs. This is because the dampers are slowing the response of the springs to return the car to ride height after a disturbance.

Reset the dampers to 1 click softer and that is your first iteration damper setting.

Now, hook up the anti-sway bars to full soft and stiffen 2 steps each iteration.

When lap times get longer, soften to 1 setting below that lap's setting.

Now, you can adjust front to rear balance by adjusting the front or rear sway bar independently and repeating the lapping until you get the desired balance.

Stiffer front sway bar= more understeer and a sharper, quicker rocking transition in quick chicanes where you so not have time to reach steady-state cornering.

Stiffer rear sway bar= more oversteer/ quicker rotation on turn-in to sharp, tight corners.

Remember, the higher the natural frequency of the spring system, the stiffer the damper needed. The natural fequency of the suspension oscilations is f=(k/m)^(1/2) so the stiffer the spring and the lighter the mass (either sprung or unsprung), the higher the frequency and the stiffer the damper required.