Preventing wheelhop - Coilover settings?
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Preventing wheelhop - Coilover settings?
I went to the track for the first time with my new coilovers, and by recommendations of a friend, I set them to full soft (dampening) for the first run.
I ended up getting horrible wheelhop and netted a 2.3 sec 60'
After adjusting the dampening to full hard, there was a LOT LESS hop, and a 1.9 sec 60' was attained.
I was told after my passes that my tires were waaay overinflated (~26 psi), so I'm going to lower the pressure quite a bit more next time, but I'd still like to know what the rear (and front) coilovers should be set to.
They're Tein FLEXs if it makes any difference.
To answer some questions that might come up: I'm on 285/40-17 street tires, and I'm slipping the clutch slightly at 4K rpm. I'm using spark-cut 2-step rev limiter, which spools me to about 3.5 Psi off the line. Next time out I'll most likely be on 275/40-17 BFG DRs.
Cheers,
~Alan
I ended up getting horrible wheelhop and netted a 2.3 sec 60'
After adjusting the dampening to full hard, there was a LOT LESS hop, and a 1.9 sec 60' was attained.
I was told after my passes that my tires were waaay overinflated (~26 psi), so I'm going to lower the pressure quite a bit more next time, but I'd still like to know what the rear (and front) coilovers should be set to.
They're Tein FLEXs if it makes any difference.
To answer some questions that might come up: I'm on 285/40-17 street tires, and I'm slipping the clutch slightly at 4K rpm. I'm using spark-cut 2-step rev limiter, which spools me to about 3.5 Psi off the line. Next time out I'll most likely be on 275/40-17 BFG DRs.
Cheers,
~Alan
#2
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How many pounds of boost are you pushing throughout the entire run? What PSI is recomended for the rear tires? I would really like to see your car at the track one of these days. Hey why dont you come with us to our track day on Saturday the 25th at Sacramento Raceway?
Last edited by JspecSC3; 02-23-06 at 05:52 PM.
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stiff rear/soft front. that will give you maximum weight transfer to the rear for traction. also, if thats not enough, you can unbolt the front sway bar endlinks and pull off the bar to get a little more lift in front.
as far as psi goes on a street tire 26psi is waaaaay too high. the right pressure to run really depends on the tire as far as sidewall characteristics but usually sub-20 is a good range. better too high than too low though...if you go too low you run the risk of tearing your sidewall. thats badnews =)
as far as psi goes on a street tire 26psi is waaaaay too high. the right pressure to run really depends on the tire as far as sidewall characteristics but usually sub-20 is a good range. better too high than too low though...if you go too low you run the risk of tearing your sidewall. thats badnews =)
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Hmmm thats interesting.. i always thought it was better to have the car stiff in the front and softer in the rear so when the weight transfers to the rear, the suspension will dampen and create more traction for the rear tires???
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Originally Posted by JspecSC3
How many pounds of boost are you pushing throughout the entire run? What PSI is recomended for the rear tires? I would really like to see your car at the track one of these days. Hey why dont you come with us to our track day on Saturday the 25th at Sacramento Raceway?
Interesting....SacramentoRaceway.com is down.
Looks like I have some confllicting answers on my wheelhop problem. Logically I would think that the rear should be soft and the front hard, so the weight transfers to the rear, but like I said, with that setting, I got some really bad hop. It might have been a coincidence but I can't risk doing something like that again, especially with my U-joint already giving me the warning clicks.
I'd really like to hear from people that have gone though all the trial and error and have come up with an answer.
~Alan
#6
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Originally Posted by SPORTcoupe
I'm running about 9.5 Psi the rest of the run. I usually run the tires at 32 Psi for daily driving, but next time at the track I'll try ~18 Psi. I wish I could make it tomorrow but I have plans most of the day.
Interesting....SacramentoRaceway.com is down.
Looks like I have some confllicting answers on my wheelhop problem. Logically I would think that the rear should be soft and the front hard, so the weight transfers to the rear, but like I said, with that setting, I got some really bad hop. It might have been a coincidence but I can't risk doing something like that again, especially with my U-joint already giving me the warning clicks.
I'd really like to hear from people that have gone though all the trial and error and have come up with an answer.
~Alan
Interesting....SacramentoRaceway.com is down.
Looks like I have some confllicting answers on my wheelhop problem. Logically I would think that the rear should be soft and the front hard, so the weight transfers to the rear, but like I said, with that setting, I got some really bad hop. It might have been a coincidence but I can't risk doing something like that again, especially with my U-joint already giving me the warning clicks.
I'd really like to hear from people that have gone though all the trial and error and have come up with an answer.
~Alan
Most people make that mistake. People want the rear to "squat". In actuality you want the rear to lift from the axle. This indicates that the real action goin on is increased downward force to the wheels. In essence the car is "planting" the tires in the rear.
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Thank you! That makes perfect sense. With the proper pressure in the tire and stiff rear dampening, instead of the force being absorbed by the coilover, it will be used to push the tire down into the ground.
What is the reasoning for the soft front? I'm guessing it's so that the car doesn't do a 'bounce' when the weight comes back to the front. Am I right?
~Alan
What is the reasoning for the soft front? I'm guessing it's so that the car doesn't do a 'bounce' when the weight comes back to the front. Am I right?
~Alan
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you want it soft in the front not to dampen the front on the bounce but so you allow the front to lift more without having to also lift the weight of the wheels or deal with the ground friction. its the lift in the front that transfers the force to the rear. thats why i also said you can remove the front sway bar. it will allow more lift since the shocks will each be independent.
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i just bought some tein flex too, just to confirm,the ones for our sc's and supra's don't come with camber adjust. plates right? One more thing..how stiff do u like it in other words, what do u set yours at?
Last edited by scoarer; 02-27-06 at 06:33 PM. Reason: eh
#11
are you guys dragging or cornering wheel hop on the rears you need a lsd. fill your gas with 3/4 of a tank instead of half full the weight will help. suspensionwise raise ur car a little dont preload your springs soo much you need suspension travell if you have a rear strut tower brace tighten it. ive ran on a ae86 for 4 years wheel hop and understeer are almost always present in that car good luck
#12
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Originally Posted by Cmedrift
are you guys dragging or cornering wheel hop on the rears you need a lsd. fill your gas with 3/4 of a tank instead of half full the weight will help. suspensionwise raise ur car a little dont preload your springs soo much you need suspension travell if you have a rear strut tower brace tighten it. ive ran on a ae86 for 4 years wheel hop and understeer are almost always present in that car good luck
Wrong school of thought. This is regarding drag racing.
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Originally Posted by scoarer
the ones for our sc's and supra's don't come with camber adjust. plates right?
Originally Posted by scoarer
how stiff do u like it
Originally Posted by scoarer
what do u set yours at?
~Alan
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Originally Posted by scoarer
i just bought some tein flex too, just to confirm,the ones for our sc's and supra's don't come with camber adjust. plates right? One more thing..how stiff do u like it in other words, what do u set yours at?
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thanks guys, i just put them in last night and im loving them..the only thing is that even on the stiffest setting i can still push the front and rear end down. But then i tested them out at an empty parking lot and i don't feel any body-roll at all and it makes controling the car sideways alot easier. Will ajusting the spring preload make it any stiffer?