alignment problem? or suspensions?

[dezpimpdada]

02 boxster S 19x8.5 front 235/35/19 19x10 rear 275/30/19

hi all, im getting uneven wear ( cupping) on all 4 tires (inner) , was told the alignment was off by tire shops. however my mechanic says its the suspension. any thoughts???

also i was asked to rotate the tires around so inner becomes outer before doing alignment to prevent/ correct the problem. now why would that matter if the alignment is good that should take care of the uneven wear isn't it?

i heard the best for porsche is the laser type alignment, called some shops they all use infrared, does it make any difference?

thanks for ur help

anyone know good alignment place in vegas??

[LVDell]

2 things:

1. Not sure why somebody would tell you it is your suspension. That would need to be clarified. What comes to mind for me is that either you run with too much pressure in your tires (more unlikely) or you have a "typical" Porsche setup. Just depends on where the wear is. On the inner 1/3 of the contact patch? Just a camber issue.

2. A good place in Vegas (used to live there and know ALOT of the guys in the P-Car circles). Call up Premier Sportscar Service. They "used" to run P-Cars in the racing series but have since moved over to F-cars. However, when I left last year they were still a certified facility to perform warranty work. Also, it helps that they KNOW these cars as they are a race shop. If they cannot help you then ask them for suggestions where to take it. The BEST indy in Vegas for P-Cars is Carl's Place. The owner is our old Vegas chapter PCA president and the greatest guy you could meet. He will steer you in the right direction if he can't do the work. Very honest, very reliable, and very reasonable with rates.

Hope that helps some.

[Dyno]

Warning! This post comes from a guy who's never owned a Porsche!

Cupping has been an issue since cars started using rubber tires. The causes are generic -- not Porsche specific. Generally, cupping can be caused by out-of-balance wheels and/or worn shocks. Is is the result of the tires literally bouncing themselves down the road in rhythm with wheel rpm, wearing depressions (cups) in the tread. You can see how an out of balance wheel can cause the wheel to bounce, and bad shock would not do a good job of damping this vibration. Worn components, like ball joints, can cause this, too. Your mechanic is thinking in these terms.

If cupping is only on the inside, it might suggest excessive negative camber, but then again, I would expect a sports car to run some negative camber anyway. If this is the issue, it will be obvious when the alignment is done.

Your tire guy wants you to flip the tires around because the cups -- if they get big enough -- actually exacerbate the bouncing, creating a death spiral of vibration/wear/more vibration/more wear. You need to break that cycle.

Both pieces of advice could be right. A good alignment should always include a thorough inspection of the suspension components anyway because they are inter-related.

Edited June 1, 2007 by Dyno

[LVDell]

If cupping is only on the inside, it might suggest excessive negative camber, but then again, I would expect a sports car to run some negative camber anyway. If this is the issue, it will be obvious when the alignment is done.

not excessive camber, but rather just "any" negative camber. Remember, neutral camber is what you are ALWAYS shooting for (0). Running negative camber in these cars aids in lateral turns but wears down the inside track on the tire. Perfect example is I corded a set of PS2's on my GT3 with less than 5K miles b/c the camber setup was more of track setting. It's all a compromise. The other issue at play here is the toe settings on the car. If he has any toe dialed in outside of nuetral (or close to it) he could be srubbing the tire in a non linear fashion.

[dezpimpdada]

thanks LVDell i will call those places this weekend!!!

[k-vic]

02 boxster S 19x8.5 front 235/35/19 19x10 rear 275/30/19

hi all, im getting uneven wear ( cupping) on all 4 tires (inner) , was told the alignment was off by tire shops. however my mechanic says its the suspension. any thoughts???

also i was asked to rotate the tires around so inner becomes outer before doing alignment to prevent/ correct the problem. now why would that matter if the alignment is good that should take care of the uneven wear isn't it?

i heard the best for porsche is the laser type alignment, called some shops they all use infrared, does it make any difference?

thanks for ur help

anyone know good alignment place in vegas??

Sounds like the tires to me. If the cupping is on the edges inside or out then the tire side walls are not holding up under harsh driving and may need more pressure or just slow down on corners. If you run your hands over the cupping and you can feel it in one direction but not in the opposite direction then this is call feathering.

If it was suspension or wheel alignment then how are all the wheel affected the same

But poor quality tires do the same

[dezpimpdada]

some updates;

i recently got all wheels balanced and tires rotated (re-mounted) the drive on the freeway got much better, however as i hit over 85 miles the steering wheel and car start to shack again. im starting to think the wheels are not straight or is it just the stiff suspensions. i remember with factory 17's it was quite stiff too but not that noticeable.

i talked to the dealership and they said its normal, but i can't drive for long time at high speed without having my hands going numb. that doesn't seem right to me :o

[rushrevisited]

some updates;

i recently got all wheels balanced and tires rotated (re-mounted) the drive on the freeway got much better, however as i hit over 85 miles the steering wheel and car start to shack again. im starting to think the wheels are not straight or is it just the stiff suspensions. i remember with factory 17's it was quite stiff too but not that noticeable.

i talked to the dealership and they said its normal, but i can't drive for long time at high speed without having my hands going numb. that doesn't seem right to me :o

Sounds like your dealer is just throwing up their arms and giving up - for them to save that is "normal" is not true...

[Toby]

02 boxster S 19x8.5 front 235/35/19 19x10 rear 275/30/19

hi all, im getting uneven wear ( cupping) on all 4 tires (inner) , was told the alignment was off by tire shops. however my mechanic says its the suspension. any thoughts???

also i was asked to rotate the tires around so inner becomes outer before doing alignment to prevent/ correct the problem. now why would that matter if the alignment is good that should take care of the uneven wear isn't it?

i heard the best for porsche is the laser type alignment, called some shops they all use infrared, does it make any difference?

thanks for ur help

anyone know good alignment place in vegas??

Sounds like the tires to me. If the cupping is on the edges inside or out then the tire side walls are not holding up under harsh driving and may need more pressure or just slow down on corners. If you run your hands over the cupping and you can feel it in one direction but not in the opposite direction then this is call feathering.

If it was suspension or wheel alignment then how are all the wheel affected the same

But poor quality tires do the same

My car does the same thing. It "recurred" (never really went away) through multiple sets of tires, two set of rims, multiple alignments (by different shops), and even a full racing spring/shock/sway/toe link change. Now I just ignore it.

[dezpimpdada]

My car does the same thing. It "recurred" (never really went away) through multiple sets of tires, two set of rims, multiple alignments (by different shops), and even a full racing spring/shock/sway/toe link change. Now I just ignore it.

thanks Toby n sorry to hear u have the same problem. i guess the only way to fix that is to trade in for a Lexus .........j/k

heck i will just try a new set of tires. Kuhmos r no good!!!