Discussion
Can anyone help? I am new to the forum and I have a very early S1 (for about 7 years), the old girl's getting on a bit now and everything appears to be going south ! I have Spax fully adjustable shock absorbers (both damping and ride height) and I want some new springs. Does anyone know what length and rating they should be ? I have heard of Koni's being fitted to some models but not the spax, and I do know the suspension changed alot in the early days. The suspension is so low I'm wrecking my stainless exhaust !
You need to take them off and measure the length. You need the free length, compressed length and the rate. IMHO 400lbs/in front and 300 rear would be a stiff set up and 200/150 soft. You can then calculate what length and rate you want. Assuming that you have wound the springs up to their full height you had better add 100mm to the free length of the new springs ie 50mm to make the car 50mm higher and 50mm to bring the springs to the centre of the adjustment range.
Beaing in mind that due to the damper geometry, increasing the front spring length by 10mm increases the front ride height by about 14mm; increasing the rear spring length by 10mm increases the rear ride height by about 17mm. If you do change the ride height you will need to reset the camber and toe.
This is getting complicated ! My current rear springs drop out of the mountings when fully jacked up (which can't be good !)and measure approx.9 1/2 inches in length. The back end also dips harshly under accelleration, i've tried winding the dampers up a bit but only achieved a harsher ride and a bad back. I know TVR changed the rear geometry after the early cars. Is there an easy calc to use to get the ideal spring rating or is it just going to be trial and error ?
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