Sub8

Hi all. Just finished fitting coilovers to my c5 Z06 and have set ride heights with the GM tool (I made one). Set to 25 & 90mm front and back. Set geometry and then corner weighted the car and got within 0.5% cross weights with me in it (+100kg).

Question - How much ride height variability is acceptable as a result of corner balance? I have a difference of 5mm at the rear and 1.5mm at front (with GM tool again). Ended up with:

408.5 398
391.5 360.5

Total: 1558.5kg


Thanks.

Nowanker

Some cars are skewed... correcting the imbalance aggravates the ride height situation, and vice-versa...
Far as I know, there isn't any hard and fast spec for it. I just try to 'spread the pain'...
Not sure where the factory measurements are taken, but 5mm measured might translate into a pretty big number at the wheel.
Can you post the heights?

tw78911sc

I know body panels can vary, but I was using top of the arch measured through the center of the wheel. I have no means of getting a corner balance but want to be as close as possible before I take in for alignment. I know with old Porsches we measured chassis rake on the door sills, is there a preferred rake for the C6Z? I am shooting for 26.25 top of front wheel arch and 26.75 on rear.

YOur corner balance numbers look REAL close, with driver ballast 1/2 full gas?

Sub8

Yup.

To fender (Inch):
LF: 26 5/8 RF: 27 1/16
LR: 27 5/8 RR: 27 7/8

LCA Tool measurement (mm):
LF: 24.6 RF: 26
LR: 81.7 RR: 86.7

Nowanker

Fiberglass body panels are notoriously uneven, somewhere off the chassis is always best anyway... Looks like the factory tool picks up from the lower control arm?
Since both right side F&R are higher than left side, dropping them (or raising the right) will get you more even on height with minimal disturbance to cross weight. With a little playing around, I'll bet you can get them pretty close
Sway bars disconnected?
Lots of 'stiction' possible in new shocks, ('specially Bilsteins!), recommend jouncing the car thoroughly, or ideally driving it between adjustments.
Good luck!

Sub8

Ride height started the same, these heights are after corner weighting.
Drop links disconnected.
Nitron coilovers.

sccaGT1racer

Starting with your ride height where it needs to be and sway bars disconnected. Put the car one scales and adjust the cross weights diagonally. As an example if you add 1 turn to the LF and RR you will remove 1 turn RF and LR. This method will keep the ride heights as close to what you started with as possible.

fmcokc

^^^^^^^ This

But looking at your current weights, I would try adding a bit to the left front and re-measure.

voda1

10 kilo diet?

Sub8

Yeah - that's pretty much what I did. I've also got quite a heavy trans cooler and pump on the drivers side rear. That's probably helping.

Nowanker

If the goal is to even out the ride height, there's adjustment room still on the table.

sccaGT1racer

You should move the heavy cooler and pump to the right rear.

Sub8

Lol, long day yesterday. Pump and cooler are on the right side not drivers side.