996 GT3 spring rates

[SignalGruen]

Hello all,

I've recently acquired a 996.1 GT3 which was imported from Japan - it must have been a track toy for the previous owner since the suspension is pretty stiff. At the moment it's running unknown coilovers (possibly JRZ?) and Eibach springs - 220N/mm at the front and 350N/mm at the rear. As an interim measure is it feasible to get some Eibachs at near stock GT3 rates or evening something like a 100/140 combo or would this be a bad idea ? I would eventually like to replace the whole suspension setup but considering that new springs would cost me around £300, I would like to try and get the car somewhat driveable until winter.

Cheers.

[Steve Rance]

If the shock absorbers have been valved to match the spring rates currently on the car ( which they should have been) you may compromise the effectiveness of the combination by fitting substantially lower spring rates. I would advise that before you do anything else, you establish what your dampers actually are and how they are set up.

[SignalGruen]

Thanks gents. Sort of confirms what I suspected. May simply bite the bullet and replace the suspension with something like the Ohlins R&T and try and sell the current setup.

Cheers.

[iguana]

I drove that approx 800m when I collected it for you & thought I was going to end up in the hedge! Been a while since I drove a mk1 & thought there was no way it was that stiff as standard, so im glad my old memory was correct

[d41d8cd9]

Slippydiff said:

In all honesty the spring rates given for the OE springs aren't that useful because they're progressive rate items, and the 35N/mm may apply to the initial (soft) windings of the spring, or a combination of the soft and hard windings.
I tried to dyno a set of brand new OE springs, unfortunately it wasn't a lot of help. In the end I ran 30 or 32N/mm non progressive rate fronts and 65N/mm non progressive rears with the Ohlins on my road use only GT3. But the 3 way Ohlins were valved specifically for the those spring rates.

I was under the impression the 996.1 and 996.2 GT3 had linear springs, with progressive springs on the 996.2 GT3 RS.

Edited by d41d8cd9 on Sunday 19th July 23:01

[d41d8cd9]

Slippydiff said:

Looking at a photo of them, you may be correct about the fronts, but the rears are definitely progressive rate.

Having dug up some pictures that looks to be the case, yep. RS has the same rear part number and a different front, so I guess it went to a progressive front.