Optimum Ride Height for NA6

[Steve Tinker]

I need some advise for my 1989 NA6 from you suspension gurus on this site.
Last year I bought a secondhand set of Ohlins shocks with Eibach springs adverised on this site - the shocks don't have any spring or damper adjustments so I suppose they are at the lower end of the Ohlins catalogue.... I fitted them last weekend with the help of the instructions on the Big Forum Garage section - no real problems and I had them installed in 4 - 5 hours. I tried them down one of my local twisty roads and the improvement is quite noticable to say the least - especially in quicker turn in. Good compliant ride and not too stiff with the Eibach springs. However, when I measured the ride height of the car I found the rears where 340mm from the tip of the guard to the centre of the wheel (good), but the fronts are a very low 290mm. Going on what I have read on this forum, the fronts should be about 320mm.
Question #1 is, is this height too low for optimum roadholding (no trackwork anticipated) - it feels OK on the road but I have not dríven it in anger yet. If the ride height really needs to be increased (I would like to keep this setup) is it feasable to install a 20mm spacer on top of the front shocks where it bolts into the turret to increase the rideheight - there is plenty of thread available on the two retaining bolts in the engine compartment.
Question #2 is that the shock perch height is non adjustable but the perch "sits" only on on a steel circlip which lies in a machined groove in the shock lower body - this is the only thing that stops the perch sliding down to the bottom of the body. Is my maths wrong because that means the spring is tensioned onto the perch which is held in place by only the circlip, so the circlip is virtually holding up the car weight (or a quarter of the car weight as there are 4 shocks). Is this normal for a car shock (the original Mazda shock I took off has the spring secured by the perch welded to the shock body. I've had much more experience with motorcycle suspension (different again) & I'd hate the bloody thing to collapse on me.....
All help gratefully received.

[Garry]

Looks bodge but yeap, the circlips are holding up the car. The Koni's use the same system.

For the front ride height I would try either getting a spacer made up to fit on top of the circlip and under the bottom spring seat or getting another groove machined into the shock body a bit higher up. Either of these methods are prefered to adding a spacer between the top of the shock and the body. By raising the spring seat you will regain some of the lost suspension travel and increase ground clearance. Adding a spacer on top of the shock will only increase your ground clearance.

One thing to remember though, due to the ratios on the lower control arms you'll only need roughly 15mm change in height at the shock to get around 20mm at the guard.

[Steve Tinker]

Thanks for the info Garry - I'll take your advice and get a spacer made up for under the spring. I had forgotten that 15mm @ the shock can equate to a 20mm difference in the body height.
Steve