Jeremiah Harbach

I have an 08 C4S with stock suspension. It has 19" turbo wheels with 235/35 tires in the front and 305/30 in the rear.

The front bumper of the car is not parallel with the ground and appears to sag on the driver's side so I took the following height measurements from the ground to the top of the wheel arch through the center of the wheel:
(measurements taken with 1/2 tank of gas)

Front left: 26 1/2" (2 finger gap)
Front right: 27 1/8" (3 finger gap)
Rear left: 27 1/8" (3 finger gap)
Rear right: 27 1/8" (3 finger gap)

I've read that sometimes the driver side is higher by design but this is the opposite.

Maybe unrelated (and maybe normal?): car alignment is good but the steering wheel likes to jerk when going over bumps at high speed with PASM on.

Any thoughts on what could cause this and what I could check? I know virtually nothing about suspension but I'm a DIYer and am eager to learn!

jchapura

Check out the post #4 pics in thread https://rennlist.com/forums/991-gt3-gt3rs-and-911r/922700-ride-height-measurement.html for getting the frame height measurements.

I have in my notes these reference values for 997.1 C2S:
Porsche frame-of-reference ride height measurements
Rears - 153 +/-10mm (6.024)
Fronts - 133 +/-10mm (5.236)

After Ohlins's coilover installation and corner balancing (with 200lbs in driver seat) and no one in the car, I measured these values:
For posterity, re-measured “fender” ride height:
P=Passenger
D=Driver
F=Front
R=Rear
DF 26 3/16
DR 26 12/16
PF 26 5/16
PR 27 0/16
For posterity, re-measured “frame” ride height:
PR 5.531
DR 5.563
PF 4.500
DF 4.375