suspension suggestions

[David McLaughlin]

I have a 1970 914/6 conversion that over a few years will be a plastic GT look-a-like. What i am in search of is some recomendations of suspention parts and alignment comments for a car that will see 75-80% autocross and drivers ed use. My initial thoughts are a 21mm front sway bar, 16mm rear bar, 180lb rear springs, 21mm torsion bars (hollow?), poly bushings, and whatever bracing and reinforcement plates i can fins or fabricate with my limited mechanical knowledge.

Please tell me what you are running and what your feeling are on the subject.

Thanks all.

[John Rogers]

Your ideas sound good. I'd recommend rear shocks with adjustable heights so the car can be corner balanced easily. I'd also recommend adjustable shocks front/rear for track tunning. If you use the Automotion Koni rear shocks with threaded spring adjusters you can get lots of different spring rates, not just 140s and 180s. I had to finally go to 300# rear springs to stop lifting the front inside wheel during hard cornering at Willow Springs but I can go back to 200# for Holtville where it is rough. Good luck.

[Dave at Pelican Parts]

Actually, the parts are Weltmeister. One of the places that sold them was Automotion. Pelican can and does also sell Weltmeister parts--even ones that are not in the catalog.

I would suggest not bothering with the rear sway bar, unless you have a limited-slip diff. Maybe not even then. The rear bar can cause the inside-rear wheel to lift up in a turn, which tends to be really bad for trying to accelerate out of the turn. The stock-type design also has the misfeature of having the arms of the bar hit the trunk floor when heavily loaded in a lowered car. (E.g., going around a corner and hitting a bump.) This usually results in instant oversteer, which results in a spin. Oops.

I think that adjustable shocks are a very good idea. Ditto with adjustable spring perches on the rear. At least some of the Konis and Bilstiens come with three-position adjustable perches. Kits are available for both to convert them to infinitely-adjustable perches, though you need the small-diameter springs to do so.

I am currently running stock torsion bars, 140# rear springs, a 19mm front sway bar, and no rear sway bar. Koni gas sport externally-adjustable shocks on all four corners. I will be upgrading to a 21mm front bar, as the 19mm one is not stiff enough.

The springs and torsion bars are dictated by my class (PCA Zone 7 improved class), which is why I have not gone with stiffer ones.

Alignment is 1 degree negative camber in front, 1.5 in the rear. Max caster (or close to it), and a bit of toe-in at the rear and a tiny bit of toe-out in front. If the car were a dedicated autox/track car, the alignment would be a bit more radical.

--DD

[JTB]

I agree with DD.

I built a 75 GT Replica. I went with Koni Adjustable Race all around with adjustable spring perches (screw type) on the rear. 22mm front torsion bars, 185# rear springs. Front bar is 21mm I think and no rear bar. Definately go with the poly bushings. My car is dead neutral and flat through the corners.

I don't have alignment specs handy, but max out the front camber. Ride height is about 4.5" to the front jack point (the round boss under the front of the doors) and 5" to the rear boss.