Optimal ride height? Options

[MichiganMat]

While the motor is out of my 914 racer for repairs Im looking at the ride height and Im researching the optimal setup for a track car. Its been tough to find good answers, so Im reaching out.

My current setup is at the lowest point of the adjustable coil-overs in the rear, mounted to a stock upper-shock perch. This leaves the rear trailing arms about parallel to the ground and just a touch of rear camber.

The front is set up for the a-arms to be roughly parallel to the chassis. Im aware that the lower I go with the front suspension the more risk of bump-steer and sub-optimal geometry come into play.

On 16" rims, this gives a ride height of about 5" front and rear. To go lower I would need to raise the rear spring mounts (ala Tangerine Racing), likely raise the rear trailing arm pick-ups, and finally raise the front spindles (or just adjust the from arms lower).

What Im wondering though is what is "optimal" for a track-only 914? Is lower "better"?

[Brett W]

Lower is far from better on these cars. The suspension geometry goes to hell quickly when lowering. Without relocating suspension mounting points you can't fix the defects in the factory geometry. When racing you will need to correct the front strut geometry by, at a minimum, moving the lower ball joint down. You also need to watch the bumpsteer curve as you go lower. Rack spacers, moving the tie rod connection at the knuckle, etc all come into play when correcting these.

The rear is more complicated. Every time you change the alignment on the rear suspension, you screw up the suspension geometry. The factory left some safe room for adjustment, but that was with the big tall skinny, not sticky, 1970s technology tires.

When you go lowering these cars with modern race rubber you mess yup the location of the rear roll centers, and screw up the toe curve in relation to the camber curves, etc. I'm not saying you can't go lower than stock, but you have to be careful when you go "slamming these vehicles.