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Springs interchangeable?

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Old Oct 18, 2022 | 05:11 PM
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Default Springs interchangeable?

I’ve searched the forum and can’t find an accurate answer on the subject. I have a 991.2 C2 and was looking to lower it a bit while stiffening the suspension a bit. Im considering the H&R springs but noticed that the GTS version has a slightly different part number. I’m only assuming the difference is the spring rate is stiffer for the GTS. Anyone know any more detail on this?
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Old Oct 18, 2022 | 06:36 PM
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The GTS comes standard with SPASM, which is both stiffer and lower. Not sure if the perches are different between PASM and SPASM, but if so that would easily explain the different aftermarket part numbers (and also prevent interchange). Could also be that the shock damping is different between the two, and the aftermarket spring takes that into account -- though I doubt it.
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Old Oct 18, 2022 | 09:57 PM
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My 2014 991 C2S has the PASM Sport option, which is the same suspension as the GTS, and my understanding is the parts from a GTS bolt right on. I'd be surprised if it's not the same on the .2.

Last edited by CarreraFahrer; Oct 19, 2022 at 01:11 AM.
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Old Oct 19, 2022 | 12:54 AM
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Originally Posted by asellus
The GTS comes standard with SPASM, which is both stiffer and lower. Not sure if the perches are different between PASM and SPASM, but if so that would easily explain the different aftermarket part numbers (and also prevent interchange). Could also be that the shock damping is different between the two, and the aftermarket spring takes that into account -- though I doubt it.
I looked at this earlier - very superficially. The Rennlist braintrust said the dampers are actually different. Did not go beyond that as I realized there were other things on the car that lacked more than this (differential). In my case, I did nothing.

OP - might be worth checking the damptronics. Same manufacturer of the Porsche suspension but note they are progressive vs what we have, which are linear. I would be leery of the lowering kits as the ride and performance will suffer.
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Old Oct 19, 2022 | 12:58 AM
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How will performance suffer from lowering springs?
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Old Oct 19, 2022 | 02:04 AM
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Originally Posted by CarreraFahrer
How will performance suffer from lowering springs?
Springs not matched to dampers, on a track or in the twisties, are not a good thing. May look sexy but just google some feedback around the tech art lowering kit and the 991 and you will see. Just depends on what you are looking for, rolling art or rolling performance.
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Old Oct 19, 2022 | 08:40 AM
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Originally Posted by Wujohn
Just depends on what you are looking for, rolling art or rolling performance.
100% this.

Show car or go car. Mod accordingly. No shame in either, just don't take one side while expecting benefits of the other!
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Old Oct 19, 2022 | 05:31 PM
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I’d like the best of both worlds if possible. I’m only looking to lower around an inch but every spring I’ve seen is progressive and I’d absolutely prefer linear if possible. Any suggestions?
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Old Oct 19, 2022 | 08:42 PM
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Don't overthink it, just change it.

You will be fine.
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Old Oct 20, 2022 | 12:00 AM
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Originally Posted by NCheok
Don't overthink it, just change it.

You will be fine.
Sure, it's only a critical suspension component.
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Old Oct 20, 2022 | 01:15 PM
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Other considerations apart from appearance: the Sport suspension (option on the S, part of the GTS package) had shorter, stiffer springs AND a stiffer roll bar. The shocks were a separate thing- PASM - with adjustable rebound rates. There are also individual alignment specs depending on configurations.

Last edited by chuckbdc; Oct 20, 2022 at 01:18 PM.
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