Mk1 GT3 spring rates

[JarmoL]

Hi there
What are the stock spring rates for mk1 GT3? (front and rear)

Thanks
Jarmo

[Slippydiff]

996.1 GT3 Front

PART NUMBER: 996 343 531 91

SPRING RATE: 35N/mm 200lbs/in


996.1 GT3 Rear

PART NUMBER: 996 333 531 91

SPRING RATE: 65N/mm 370 lbs/in

Why do you ask ?

[JarmoL]

Thanks for your quick reply. Rates seem to be surprisingly light. (compared to what I have in my 968)
Springs are not progressive aren't they?

I am asking because I am supposed to have a Manthey set up in my recently bought GT3. Just want to know the difference between the two.

[Slippydiff]

JarmoL said:

Thanks for your quick reply. Rates seem to be surprisingly light. (compared to what I have in my 968)

Heavy(ish) front engined car as opposed to heavy rear engined car.

JarmoL said:

Springs are not progressive aren't they?

No

JarmoL said:

I am asking because I am supposed to have a Manthey set up in my recently bought GT3. Just want to know the difference between the two.

Is this for road or track use ?

[fioran0]

id always thought that the 968 used a rear torsion bar layout? your post got me curious as to what rate the 968 came with but a quick google scan shows the 968 front spring rate to be 28N/mm. the 968 weighs more than a mk1 GT3 too, though only slightly. remember motion ratios also effectively change the actual rate of the spring so you might find the 968 spring is being reduced more than the 996 is through this calculation.
what springs have you on the 968?

the quickest way to check if you have a manthey suspension setup will be to look under the car and see if you have KW coilovers. this is mantheys preferred supplier, if there isnt KW its likely its not been manthey'd. manthey wont, i assume, be running stock spring rates.
perhaps asking manthey what rate they used for the mk1 (if indeed they had a go to spec) would enable you to better gauge things.

Edited by fioran0 on Monday 12th December 01:50

[Steve Rance]

You may have a geo as opposed to the KW damper kit fitted. Have a quick look at your dampers, if they arnt purple and yellow, you've probably got the geo only. To be honest, the Manthey spring/damper set up is primarily tuned to the ring and is not that extreme so I'd be surprised if the spring rates were much different to standard

[cragswinter]

JarmoL said:

my recently bought GT3.

So you bought it then?! I did notice it was up as sold, hope you enjoy such a striking looking machine

Look forward to seeing it out at the ring sometime

[JarmoL]

cragswinter said:

So you bought it then?! I did notice it was up as sold, hope you enjoy such a striking looking machine

Look forward to seeing it out at the ring sometime

Well.. I thought why not! The Guys at the 911V were great and the car was pretty much as described.

Driving it home was fun until we got near Hamburg.. temperature got below zero and it started snowing heavily. Couldn't see the car in front! We drove very very slowly for about 20 km's until we got out of it!

I will certainly visit Ring every now and then.. come to say hello if you see me!

[JarmoL]

fioran0 said:

id always thought that the 968 used a rear torsion bar layout? your post got me curious as to what rate the 968 came with but a quick google scan shows the 968 front spring rate to be 28N/mm. the 968 weighs more than a mk1 GT3 too, though only slightly. remember motion ratios also effectively change the actual rate of the spring so you might find the 968 spring is being reduced more than the 996 is through this calculation.
what springs have you on the 968?

the quickest way to check if you have a manthey suspension setup will be to look under the car and see if you have KW coilovers. this is mantheys preferred supplier, if there isnt KW its likely its not been manthey'd. manthey wont, i assume, be running stock spring rates.
perhaps asking manthey what rate they used for the mk1 (if indeed they had a go to spec) would enable you to better gauge things.

Edited by fioran0 on Monday 12th December 01:50

Yes, 968 came with the torsion bar set up at the rear. I have removed them though and have H&R coilover set up. Fronts are 90Nm and rears 130Nm at the moment. I have a turbo engine with large intercooler in there so the nose is heavier than stock 968. Of course you are correct about the effective rates. At the 968's rear it's little over half of the actual spring rate if I remember correctly.

I believe in the old days Manthey used Bilstein revalved to their specs. KW's only came in to play at later time?

[996TT_STEVO]

Steve Rance said:

You may have a geo as opposed to the KW damper kit fitted. Have a quick look at your dampers, if they arnt purple and yellow, you've probably got the geo only. To be honest, the Manthey spring/damper set up is primarily tuned to the ring and is not that extreme so I'd be surprised if the spring rates were much different to standard

Very correct Steve, was very compliant.

[996TT_STEVO]

JarmoL said:

Yes, 968 came with the torsion bar set up at the rear. I have removed them though and have H&R coilover set up. Fronts are 90Nm and rears 130Nm at the moment. I have a turbo engine with large intercooler in there so the nose is heavier than stock 968. Of course you are correct about the effective rates. At the 968's rear it's little over half of the actual spring rate if I remember correctly.

I believe in the old days Manthey used Bilstein revalved to their specs. KW's only came in to play at later time?

You would be better trying to find someone who has done the conversion... Pelican or Rennlist might have some info

[996TT_STEVO]

Try these posts... a couple of them are "For Sale" but they might provide essential info for you

http://forums.pelicanparts.com/porsche-924-944-968...

http://forums.pelicanparts.com/porsche-924-944-968...

http://forums.pelicanparts.com/porsche-924-944-968...

[Slippydiff]

JarmoL said:

Yes, 968 came with the torsion bar set up at the rear. I have removed them though and have H&R coilover set up. Fronts are 90Nm and rears 130Nm at the moment. I have a turbo engine with large intercooler in there so the nose is heavier than stock 968. Of course you are correct about the effective rates. At the 968's rear it's little over half of the actual spring rate if I remember correctly.

I believe in the old days Manthey used Bilstein revalved to their specs. KW's only came in to play at later time?

As others have said, take a quick look underneath, the KWs will be obvious as they've got stainless steel strut bodies.

Give Steve McHale at JZ Machtech a call for futher info on the Manthey KWs :

http://www.jzmachtech.com/shells/contactus.php

[JarmoL]

The car in question was "Mantheyed" when it was new, in late 2000 early 2001. I don't think Manthey used KW back then. KW was at the very beginning of their success in motorsports at this time.
Anyway, thanks for the info about the original springrates!

[Slippydiff]

You're more than welcome I saw your car down at 911V a few weeks ago, it looked a good honest example, if it had been RHD I'd have most likely bought it.
I suspect you're right, 1999/2000 was most likely pre KW at Manthey.