cosmos

I am looking for the part numbers for the GT3 RS front springs and the number for the rear springs. Are both front and rear different than the Standard GT3?

Also anyone have a picture or diagram of the front springs.

Thanks,

Viken

GT3 Front Spring: 996.343.531.95.504
GT3RS Front Spring: 996.343.531.97.504

GT3 & GT3RS Rear Spring: 996.333.531.95.504

cosmos

Ok, so the rears are the same. Cool, I am going to upgrade just my front springs to RS springs.

Mr. C4

Cos,

Why? I wouldn't play around with spring ratios without correct shock valving.

Ciao,

Johannes E.

cosmos

The RS springs are only 13% stiffer then the GT3, the spring is also progressive not linear. I dont think the 13% is going to matter much.

gtdrei

I think Cos is onto something here. The MKII front spring rate is 228lbs, rear 540. Thats a very large differential which could be one of the causes of the 'porpoising' phenomenon on bumpy roads, overall bumpy road instability, and understeer. Besides, it's not an expensive experiment, if it fails.

Robin

Greg Fishman

Adding spring rate to the front will cause the car to understeer more.

Viken

Where did you get those spring rates from? The front is clearly softer than it really feels and the rear is a tad stiffer. My car doesn't feel anything like it might have such a huge differential.

gtdrei

Viken,
Porsche Club Panorama 9/03. Front 40 N/mm linear springs, Rear 95 n/mm progressive springs. Based on my math, which has never been good, and some help from a few conversion sites, the formula is n/mm X 5.71=ft/lbs. Which delivers the results I posted. Let me know if i'm wrong.
BTW, the same article claimed spring rates for the Cup car as Front 240 N/mm with 60N/mm helpers and Rear 260 N/mm with 60mm helpers. (no progressive springs )

Robin

cosmos

Yes, you are correct, however there is enough adjustablity in the swaybars to rid the car of whatever understeer the stiffening of the front may cause. The sways can not fix the rebound or compression that can IMO be fixed by stiffer springs.

The car has serious front end issues and stiffer front spings are the only way to cure those issues.

gtdrei

Sorry, my bad, the conversion is N/mm to lbs/inch. The factor used here and some other places was N/mm X 5.7 = lbs/in. Here's one of the sites I enlisted for help
Spring Conversions

Mr. C4

I would have thought that Porsche would have sorted any such issues, perhaps your car just needs a proper wheel allignment and corner balance.

It get's very scientific the day you start playing around with the GT3 chassi components (trust me, I know) and the end result might not be any better and you will find that the stock components work best but with a more track oriented chassi set-up. = all expensive parts in the bin.

I would personally not go down the route of changing chassi components unless the car spends 99% of it's time on a track and is being trailered to and from the track.

Ciao,

Johannes E.

Biker

What about the 05 GT3, which is has softer springs (in the USA), are these cars equipped with different shocks?

Sloth

Whats with the softer springs on the 05 GT3 for the USA? I had not heard that one before...

gtdrei

Is this a fact or urban legend ? can anyone point me to where this is documented ? What's the part # for the 'softer' springs, and what's the new spring rate ? Linear, or progressive ? I have heard that there are springs with a '993' part #, but can anyone confirm ?

Robin