997.2 factory sports suspension guru?
07-04-2023 | 09:30 PM
#16
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From: Vista CA
good information, thanks for the ongoing discussion.
ride quality sucks = harsh, minimal damping, much worse than my 996 GT3. Unacceptably bad now in 2023, not sure if I thought the same when we got it in 2009.
Be well.
ride quality sucks = harsh, minimal damping, much worse than my 996 GT3. Unacceptably bad now in 2023, not sure if I thought the same when we got it in 2009.
Be well.
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stiles_s (07-05-2023)
07-04-2023 | 09:46 PM
#17
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From: NJ
2009 C2S ~65k miles + Eibach lowering springs + PASM + DSC controller
Had a clunk coming from the front left for a while now... it's gotten bad to the point I hear it every time I hit bumps < 45mph. Then like a week later, after some rough cross-Bronx NYC roads, the front right started squeaking like hell when turning the steering wheel to the right. Tried the grease the stack by the top mount to no avail.
I'm a big hobby DIY mechanic guy, but will leave chasing suspension issues to the professionals. So I take it to a local speed shop, the mechanic tells me the shocks and top mounts are on their way out. But I changed the top mounts (Lemforder from FCP) while installing Eibach springs 1500 miles ago. Apparently, the lowering springs can exacerbate any underlying conditions and accelerate wear. Not something I wasn't aware of, but didn't realize to which extent.
Anywho, the car is getting dropped off tomorrow to get a fresh set of B8s installed and the top mount will be inspected for wear / replaced. Report back soon-ish.
Had a clunk coming from the front left for a while now... it's gotten bad to the point I hear it every time I hit bumps < 45mph. Then like a week later, after some rough cross-Bronx NYC roads, the front right started squeaking like hell when turning the steering wheel to the right. Tried the grease the stack by the top mount to no avail.
I'm a big hobby DIY mechanic guy, but will leave chasing suspension issues to the professionals. So I take it to a local speed shop, the mechanic tells me the shocks and top mounts are on their way out. But I changed the top mounts (Lemforder from FCP) while installing Eibach springs 1500 miles ago. Apparently, the lowering springs can exacerbate any underlying conditions and accelerate wear. Not something I wasn't aware of, but didn't realize to which extent.
Anywho, the car is getting dropped off tomorrow to get a fresh set of B8s installed and the top mount will be inspected for wear / replaced. Report back soon-ish.
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stiles_s (07-05-2023)
07-04-2023 | 10:22 PM
#18
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From: Maryland
DSC controller is the answer
Last edited by Patrick3000; 07-04-2023 at 10:26 PM.
07-05-2023 | 01:42 AM
#20
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My 997.2 C2S came with KW V3 coilovers, but the car originally came with Sport PASM, option P17, which comes with the I030/M030 Sport Suspension option. I'm looking to go back to SPASM spec for use with the DSC Controller and lower spring rates. The B16 main linear springs are 289 lb/in FR and 637 lb/in RR - similar to a 997.2 GT3 at 280 lb/in FR and 657 lb/in RR. Along with the KW V3, the B16 are too stiff for my goals with this car. 997.2 I030 springs are linear 205 lb/in FR and progressive 371-543 lb/in RR. Source.
07-05-2023 | 10:54 AM
#21
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From: Redwood City, CA
At least based on the spreadsheet I was referencing, progressive 109-194 lb/in FR and progressive 297-514 lb/in RR. The max rates then are closer to Sport spring rates than B16/GT3 rates.
Last edited by bajabluejay; 07-05-2023 at 10:55 AM.
07-05-2023 | 01:26 PM
#22
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From: los angeles
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stiles_s (07-05-2023)
07-05-2023 | 04:52 PM
#23
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Joined: Jun 2013
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From: Redwood City, CA
super interesting. This was bilstein USA you were communicating with? I also think the internal bumpstops on the b6 and b8 are tuned to assume a certain spring length as well. The spasm springs land somewhere in the middle between the oe standard springs and a typical lowering spring.
08-16-2024 | 01:00 AM
#24
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Went with B6 Damptronic units....aside from the ride feeling more "firm" than previous (and less body roll), I tend to feel the difference on the compression stroke versus that of rebound. Imperfections in the road are much more felt, more pronounced "thunks" if you will when crossing over a pothole of sorts. I will definitely provide an update after the B16s are installed.