KneesUp
A2OC Donor
Following on from my earlier thread 'FSD Spring Mystery - help!' to which so many did help, I can now attach photos as suggested by Skipton-Mike, and report on my findings.
This morning I photographed the car with its Audi Sport rear springs fitted and measured the distances (using steel rules and set squares) from the tyre top to the arm lip leading edge. I then swopped the Springs back to the original SE items. The results are... weird...!
I also checked the FSD part numbers and they are correct for the car, as are the bumps stops.
In summary:
The Audi Sport springs gave a rear 'tyre-top to arch-rim' gap of 85mm.
The front equivalent distance with Weitec -30s is 42mm.
The Audi SE rear springs (all be it with 42,000 miles on them) gave a rear gap of 62mm.
So... instead of the Sport Springs reducing my rear ride height by the assured 10mm, they raised it by 23mm!
With the springs off the car and on the flat ground, a direct comparison of the SE Springs and the Sports springs shows the new Sport items to be 8mm taller than my SE Springs, which accounts for some of the difference. They also have half an extra coil in them. They appear the same overall width, proportion and strand width. I would suggest the other 15mm of differnence is accounted for my the SE's softer 'give' under load and their age. But it's a major difference...
Also, with the SE springs refitted and the ride height now looking far more even (still 15-20 too high at the back to be dead-level though), the car rides far more pleasingly. Suddenly the FSDs are feeling right. Before, the ride quality was simply unpleasant and uncontrolled.
I accept that judgements about car ride are highly subjective but I have been in the motor sport business all of my professional career and I do know a controlled firm ride from one that isn't. I am at least now moderately happy with my new FSD set-up. Ideally, I'd have the SE springs pre-compressed by 15mm and re-fitted, but I've rather had enough of all this now. Besides, with my space-saver and tools in the boot the rear will sit a tad lower anyway.
In conclusion, my feeling is that - and as I have stated before - that both spring and FSD batches vary at point of manufacture A LOT. I think that is largely why there are so many differing opinions among Forum contributors on various set-ups, quite apart from personal taste, of course. I really researched all this very thoroughly - a lot with Schnelletrecker's help - and my experiences seems to show that all you can really do is chance it by taking a educated punt. The rest is down to your own R&D.
Very many thanks again to all who helped me sort this out.
Richard
This morning I photographed the car with its Audi Sport rear springs fitted and measured the distances (using steel rules and set squares) from the tyre top to the arm lip leading edge. I then swopped the Springs back to the original SE items. The results are... weird...!
I also checked the FSD part numbers and they are correct for the car, as are the bumps stops.
In summary:
The Audi Sport springs gave a rear 'tyre-top to arch-rim' gap of 85mm.
The front equivalent distance with Weitec -30s is 42mm.
The Audi SE rear springs (all be it with 42,000 miles on them) gave a rear gap of 62mm.
So... instead of the Sport Springs reducing my rear ride height by the assured 10mm, they raised it by 23mm!
With the springs off the car and on the flat ground, a direct comparison of the SE Springs and the Sports springs shows the new Sport items to be 8mm taller than my SE Springs, which accounts for some of the difference. They also have half an extra coil in them. They appear the same overall width, proportion and strand width. I would suggest the other 15mm of differnence is accounted for my the SE's softer 'give' under load and their age. But it's a major difference...
Also, with the SE springs refitted and the ride height now looking far more even (still 15-20 too high at the back to be dead-level though), the car rides far more pleasingly. Suddenly the FSDs are feeling right. Before, the ride quality was simply unpleasant and uncontrolled.
I accept that judgements about car ride are highly subjective but I have been in the motor sport business all of my professional career and I do know a controlled firm ride from one that isn't. I am at least now moderately happy with my new FSD set-up. Ideally, I'd have the SE springs pre-compressed by 15mm and re-fitted, but I've rather had enough of all this now. Besides, with my space-saver and tools in the boot the rear will sit a tad lower anyway.
In conclusion, my feeling is that - and as I have stated before - that both spring and FSD batches vary at point of manufacture A LOT. I think that is largely why there are so many differing opinions among Forum contributors on various set-ups, quite apart from personal taste, of course. I really researched all this very thoroughly - a lot with Schnelletrecker's help - and my experiences seems to show that all you can really do is chance it by taking a educated punt. The rest is down to your own R&D.
Very many thanks again to all who helped me sort this out.
Richard