996 gt3 and 996 gt3rs spring lengths
05-11-2014, 08:35 PM
#1
996 gt3 and 996 gt3rs spring lengths
Does anyone know the difference in the 996 gt3 and 996 gt3 Rs front springs?
I think the Rs has a slightly stiffer front spring but wondered if the spring length is shorter on the Rs as it uses a much larger and taller front hub upright.
I'm fitting Rs front uprights and I'm unsure what front springs to go for.
Any help is very welcome cheers
I think the Rs has a slightly stiffer front spring but wondered if the spring length is shorter on the Rs as it uses a much larger and taller front hub upright.
I'm fitting Rs front uprights and I'm unsure what front springs to go for.
Any help is very welcome cheers
05-12-2014, 01:01 AM
#2
Don't you have to change both the front and rear in order to have matching roll centers? The roll center on the RS is much higher, no? If you just change the front to RS spec, how will that work in combination with the stock rear end?
Last edited by powdrhound; 03-17-2018 at 01:57 PM.
05-12-2014, 04:03 AM
#3
Yes that's right, I have all 4 uprights and subframes etc.
They are actually 997 cup parts which are basically the same as 996 Rs and RSR but with further improved roll centre and geometry.
They are actually 997 cup parts which are basically the same as 996 Rs and RSR but with further improved roll centre and geometry.
05-12-2014, 03:11 PM
#4
Former Vendor
'04 GT3 RS's front spring free length is 213mm. 8 coils á 10mm, so block length is about 80 mm and block travel about 133 mm. Just measured today b/c another reason...
05-12-2014, 07:17 PM
#5
The standard GT3 front spring is 40n/mm and the RS version is a bit stiffer at 45n/mm. The rears are the same stiffness at 81n/mm.
After a bit of experimenting, I now run Eibach 100n/mm front & 140n/mm rear on my Motons. That seems a good compromise spring rate for road & track (and will cope with slicks too if you up the bump to compensate) and isn't too stiff to drive the 'ring on. You might want to go to 160 or more on the rear of yours because of the extra weight.
After a bit of experimenting, I now run Eibach 100n/mm front & 140n/mm rear on my Motons. That seems a good compromise spring rate for road & track (and will cope with slicks too if you up the bump to compensate) and isn't too stiff to drive the 'ring on. You might want to go to 160 or more on the rear of yours because of the extra weight.
05-12-2014, 07:40 PM
#6
05-12-2014, 07:42 PM
#7
The standard GT3 front spring is 40n/mm and the RS version is a bit stiffer at 45n/mm. The rears are the same stiffness at 81n/mm.
After a bit of experimenting, I now run Eibach 100n/mm front & 140n/mm rear on my Motons. That seems a good compromise spring rate for road & track (and will cope with slicks too if you up the
bump to compensate) and isn't too stiff to drive the 'ring on. You might want to go to 160 or more on the rear of yours because of the extra weight.
After a bit of experimenting, I now run Eibach 100n/mm front & 140n/mm rear on my Motons. That seems a good compromise spring rate for road & track (and will cope with slicks too if you up the
bump to compensate) and isn't too stiff to drive the 'ring on. You might want to go to 160 or more on the rear of yours because of the extra weight.
Thanks for the advice, I'm on standard shocks still at the moment, do you think those spring rates will work with them?
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05-13-2014, 02:02 PM
#8
Ah, no, they will completely overwhelm the standard dampers & it will leap around like a demented rabbit & be generally horrible to drive. For some reason I thought you were on adjustable dampers. Aren't you running on slicks? They will never work well with road dampers or spring rates & you're likely to flex the damper rod and get premature top seal failure. Compare a "proper" damper rod diameter to the road one & you'll see what I mean!
05-13-2014, 05:41 PM
#9
Hi Nick, yes I'm on standard dampers and springs with all solid mount monoball joints with locking plates and solid top mounts.
When I was at Oulton in march that was the first and only time ive tried slicks, I'm going to be using them at dn as well as long as the weather allows.
Later in the year I am looking to put new adjustable dampers but not sure to be honest about which ones to go for,its hard to know what's best to go for without trying them.
When I was at Oulton in march that was the first and only time ive tried slicks, I'm going to be using them at dn as well as long as the weather allows.
Later in the year I am looking to put new adjustable dampers but not sure to be honest about which ones to go for,its hard to know what's best to go for without trying them.
05-13-2014, 05:48 PM
#10
NXI20, the factory Bilstein/De Carbon struts are good as it gets in regards to rod strength and stiction.
05-13-2014, 06:52 PM
#11
I can't remember the exact numbers but I measured the OEM Bilstein rod as roughly half the diameter of the Moton rod. I rebuilt the OEM suspension twice in 35K miles due to leaking top seals (new rods required both times) and have now had the Motons on for 60K miles. The Motons are still on their original everything and are working perfectly (damper dyno tested only 5K miles ago.) The car has done 146 track days (about 25/year), so maybe 45 on the original suspension & the rest on Motons so I have worn out more suspension parts, brake parts & bearings than most. Moton, GMG & Tarret parts have stood up to the punishment that the stock stuff is too compromised to withstand over the long term. Those are the simple facts.
05-13-2014, 07:01 PM
#12
If I were buying again I'd be looking at Ohlins. Even the "cheap" stuff is really well made & you really don't need more than bump & rebound 2-way adjustables.
05-13-2014, 07:10 PM
#13
Are we both talking about the same parts?
Front OEM strut rods are as 'fat' as the strut body allows, a true De Carbon design;
Rear shocks are a 'conventional' style though...
Good to hear your car and aftermarket bits are going strong
Cheers,
Front OEM strut rods are as 'fat' as the strut body allows, a true De Carbon design;
Rear shocks are a 'conventional' style though...
Good to hear your car and aftermarket bits are going strong
Cheers,
05-13-2014, 07:52 PM
#14
Hi Nick, yes I'm on standard dampers and springs with all solid mount monoball joints with locking plates and solid top mounts.
When I was at Oulton in march that was the first and only time ive tried slicks, I'm going to be using them at dn as well as long as the weather allows.
Later in the year I am looking to put new adjustable dampers but not sure to be honest about which ones to go for,its hard to know what's best to go for without trying them.
When I was at Oulton in march that was the first and only time ive tried slicks, I'm going to be using them at dn as well as long as the weather allows.
Later in the year I am looking to put new adjustable dampers but not sure to be honest about which ones to go for,its hard to know what's best to go for without trying them.
