Need all your help guys & gals

[johno]

It seems positively impossible to find what the ride height should be for an S.

I know later cars ran higher, and I am sure the V8S and S4 were different again.

The help I am after means you'll need to get under your car with a measuring device as I want to build a picture of what height people are running their cars at.

The suggested measuring points are....

Rear - Centre of outer trailing arm bolt to floor

Front - Centre of front wishbone bolt to floor

If people are running non standard wheels and tyres please give details.

Mine is still running too low at the front and I'm interested to compare....that's all folks !!

Cheers


Mark

[johno]

Cheers Graham,

I'll be rechecking mine tomorrow and I'll post the figures once I've got 'em.

Cheers

Mark

[johno]

Peter,

As you may remember I have your old (prototype) Gaz dampers at all four corners now. What I don't seem to be able to sort is the front ride height. It sits too low on the o/s even with me adjusting it up. Both front springs are apparently fine but both front wheels catch the wheel arches on full lock.

They also catch if in a bend hard and hit a bump. This can't go on, unfortunate as the handling is great with brilliant turn in which I'm sure I'll lose if I go higher again at the front.

I need to get this set up right ready for Zolder !!

Are you going to feel generous in Belguim and take me for a flying lap to see what you can really do in a S ??

Cheers

Mark

[johno]

If I were to stiffen the ARB bushes would this help prevent some of the issues I am having ???

Poly bushes to replace the original rubber ones ??

[johno]

I have adjusted the damper stiffnes to try and stop it. It is definitely the wheel catching the body and not the damper on the bump stops (evidenced on wheel arch)

The body fit is wrong and not square. The ride height hadn'y been changed from Peters car I suspect when they were fitted to mine as it looked a little like a 'hot rod' when I picked it up !!

I have lowered the rear and am just about happy with that. It just seems I am having to raise the front a large amount to get it to stop catching the bodywork.

Cheers for the suggestions I will return to it today and raise it some more and see how I get on.

Cheers

Mark

[johno]

quote:

quote:It sits too low on the o/s even with me adjusting it up.

Measured how? I guess you know you can't rely on the bodywork height!

Happy to take you for a spin round Zolder, its a great circuit. There is some in-car video from 2001 at www.roop.ik.com.

Cheers,
Peter Humphries (and a green V8S)

Big thanx Peter, I look forward to that a lot. May even buy you a beer !!

See you at Zolder..

Mark

[johno]

quote:


Once the wheels are on a flat surface, with the sort of spring rates you're using you can measure the corner wights by measuring the length between spring seats, and measure the corner heights by masuring the length between damper mounting bolts. If you can measure these dimensions within a mil or so that's fine, ideally go round the car twice and average the readings.

quote:

Peter,

Will there be any kind of ambient weight transfer left as I get out of the car. Am I best to bounce each corner a couple of times to make sure the car has settled level before I start. I doubt there would be but we are talking millimetres here ???

quote:

Set the left and right spring seats at the same position on the damper (front and rear) and with the car on your level surface measure the spring lengths to check there is no twist in the car. They won't be identical side-to-side, but the ratio of left-to-right should be the same at both ends.

quote:

By this you mean that if spring lengths are different then the difference should be equal front and rear on that side to compensate for any greater weight on that side ?

quote:

Assuming you have not got any measurable twist, the next step is to level the ride height side-to-side. Measure the damper lengths to see which side is low. Since the weight is almost exactly central on a typial S this is probably close enough to go with as it is, but if you do need to adjust it wind the front and rear spring seats on that side to bring it up to the height of the other side. If you do front and rear together you can do this without reintroducing twist, but remember the rear dampers run at higher leverage than the front (1.7 vs 1.4) so will need correspondingly less adjustment. After you've got it level, recheck there still isn't any twist, if the ride height was a long way out the ARB may have given you some twist which will now be apparent. Depending how far out it was in the first place you might want to go round a couple of times to get it completely level with no twist. But as I said, if you have a straight chassis and start with all the spring seats set the same I would be surprised if you had to make any significant adjustment.

quote:

Rather than the car being level, what in fact you are doing is making sure the damper lengths correspond to each other ? You could still end up with the front being lower or the reverse but the lateral level would be correct ??

quote:

Now you're ready to start playing with the ride height. This is largely a matter of trial and error to find how much travel/clearance you need in normal driving. If it tends to bottom out, your main options are fit stiffer springs, stiffen the dampers up, move the bodywork out the way or increase the ride height. It's always a compromise, but don't forget you have other options than just increasing the ride height.

quote:

I will be replacing the ARB mounts with Poly bushes before I start this exercise.

quote:

When you adjust the ride height always adjust left and right spring seats together by the same amount to ensure you don't introduce twist or roll. If you're running it as low as possible and in danger of running out of travel you also need to make sure the suspension bottoms out on the bump stops before the wheel hits the body, and bear in mind the bump stops are flexible and will crush half an inch or so on impact. If you need to adjust the bump stops you can put C section spacers underneath (Merlin sell them, or make your own) or get longer bump stops. But you should have the car set high enough that you don't normally hit the bump stops as this strains the suspension, gives an uncomfortable ride and *really* messes up the car's handling!

quote:

This doesn't happen at the front I'm quite sure. The rear is a different matter though. I have the ride height set so that there is 4 fingers clearance to the body work from the top of the tyre. Rough as a badgers butt I know but a starter from the old set up. With this the dampers are very near to the bump stops and can't do anything but hit them. It does effect the handling and in my limited knowledge I reckon the Gaz dampers are too long. I have blown 2 pairs apart at the rear, neither of which were wound right down at all. These seem to be far better.

If I wind the height up at the rear then I loose -ve camber and wind up with wheels like a 2CV !

quote:

PS sorry the above is so long winded!

Sorry the reply seems even longer. As for the camber I will let some pro adjust that one. I need to get the suspension back to base settings and go again from there. I am happy with the handling at the moment generally I just think it can be improved and with the roads and driving style I have I can't keep having wheels rubbing body work !!

Cheers

Mark