Coilover Spring Rates for Slammed LS'
09-28-10, 09:29 PM
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Coilover Spring Rates for Slammed LS'
I was wondering what people that are slammed on coilovers run in terms of spring rates? I'm pretty low right now and the rear of the car bounces around as if i was on cut springs.
Current setup is JIC SF-1s, which are non-dampening adjustable. I was thinking about getting some Swift Springs to correct this problem but don't know if that will actually resolve the problem or not. And if it does what spring rates i should order? Any advice guys?
Current setup is JIC SF-1s, which are non-dampening adjustable. I was thinking about getting some Swift Springs to correct this problem but don't know if that will actually resolve the problem or not. And if it does what spring rates i should order? Any advice guys?
09-29-10, 09:11 AM
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but it only started doing this after i lowered the car another inch or 2. Before that the coil overs preformed excellent besides the spring rates being a little bit too soft for my taste.
09-29-10, 12:09 PM
#6
wait, SF-1s are the old-style jic coilover, they havent sold those in forever, neither do they service them anymore i believe.
the reason your ride quality went down so much when you lowered more is because they are a single-tap coilover, with the ride height being adjusted by the spring preload.
most modern coils are a dual-tap style, with 2 separate adjustments available for spring preload and lower bracket height. this lets you ride relatively low without touching the spring preload, thereby enhancing the ride a good bit.
the problem with running too low on a single tap coilover is that it forces the shock to work outside of its optimal range, causing bouncing/bottoming out, and eventually premature failure depending on how outside of its range it is.
the reason your ride quality went down so much when you lowered more is because they are a single-tap coilover, with the ride height being adjusted by the spring preload.
most modern coils are a dual-tap style, with 2 separate adjustments available for spring preload and lower bracket height. this lets you ride relatively low without touching the spring preload, thereby enhancing the ride a good bit.
the problem with running too low on a single tap coilover is that it forces the shock to work outside of its optimal range, causing bouncing/bottoming out, and eventually premature failure depending on how outside of its range it is.
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09-29-10, 04:40 PM
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wait, SF-1s are the old-style jic coilover, they havent sold those in forever, neither do they service them anymore i believe.
the reason your ride quality went down so much when you lowered more is because they are a single-tap coilover, with the ride height being adjusted by the spring preload.
most modern coils are a dual-tap style, with 2 separate adjustments available for spring preload and lower bracket height. this lets you ride relatively low without touching the spring preload, thereby enhancing the ride a good bit.
the problem with running too low on a single tap coilover is that it forces the shock to work outside of its optimal range, causing bouncing/bottoming out, and eventually premature failure depending on how outside of its range it is.
the reason your ride quality went down so much when you lowered more is because they are a single-tap coilover, with the ride height being adjusted by the spring preload.
most modern coils are a dual-tap style, with 2 separate adjustments available for spring preload and lower bracket height. this lets you ride relatively low without touching the spring preload, thereby enhancing the ride a good bit.
the problem with running too low on a single tap coilover is that it forces the shock to work outside of its optimal range, causing bouncing/bottoming out, and eventually premature failure depending on how outside of its range it is.
09-29-10, 08:47 PM
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the first issue is you're probably hitting the bumpstops. if there are external stops you may try removing them (not real familiar with sf1), but that may effect life expectancy.
single tap coilovers are pretty outdated. i wouldn't go more than 2k+ on the springs since you can't revalve. the sf-1 had fairly aggressive spring rates from the factory iirc.
another issue may be your geometry. you look like you're at about the height mine was at last time i drove it and that last 1" has some drastic effects on ride quality. you may want to grab an ss kit and then raise your coilovers 20mm to retain the same ride height.
single tap coilovers are pretty outdated. i wouldn't go more than 2k+ on the springs since you can't revalve. the sf-1 had fairly aggressive spring rates from the factory iirc.
another issue may be your geometry. you look like you're at about the height mine was at last time i drove it and that last 1" has some drastic effects on ride quality. you may want to grab an ss kit and then raise your coilovers 20mm to retain the same ride height.
09-30-10, 08:49 AM
#12
Not all single height adjustment coilovers are at a disadvantage. Many are better than the dual height adjustment coils even if adjusted using the spring perch.
If a coilover is well designed, it should provide good damping almost throughout the whole stroke. Take a quick look at a quality coil's force vs displacement graph and a cheaper dual adjustment coils like KSport/Megan. It's going to be very obvious as to which coil will perform better regardless of height.
The issue with your JIC is that they may not be in their optimal height range. Like most said, you're either hitting the bump stops or the shocks cannot perform their duty when dropped low. Getting new springs will not help. Stiffer springs will increase your bounciness. Either raise up your car or get a different set of coilovers.
If a coilover is well designed, it should provide good damping almost throughout the whole stroke. Take a quick look at a quality coil's force vs displacement graph and a cheaper dual adjustment coils like KSport/Megan. It's going to be very obvious as to which coil will perform better regardless of height.
The issue with your JIC is that they may not be in their optimal height range. Like most said, you're either hitting the bump stops or the shocks cannot perform their duty when dropped low. Getting new springs will not help. Stiffer springs will increase your bounciness. Either raise up your car or get a different set of coilovers.
09-30-10, 12:42 PM
#13
My friend is riding on 26kg front and 20kg rear springs on his LS400.
More info here-https://www.clublexus.com/forums/vip-style/479691-tanabe-super-low-form-damper-coilovers-from-japan-pics.html
Pics of the install-http://kyoei-usa.com/blog/2010/02/ucf20-ls400-gets-new-tanabe-super-low-form-damper-coilovers/
More info here-https://www.clublexus.com/forums/vip-style/479691-tanabe-super-low-form-damper-coilovers-from-japan-pics.html
Pics of the install-http://kyoei-usa.com/blog/2010/02/ucf20-ls400-gets-new-tanabe-super-low-form-damper-coilovers/
09-30-10, 03:47 PM
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Kinda switching the subject, but could i couple the JICs with airbags later down the road? And would that alleviate the problem or would i need to still get new coilovers to correct the current problem?
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