Diagnose this...I know you can

[trube78]

You have 18" sport classic I wheels with 15mm spacers all around and the standard sport suspension (i.e. not the ROW) --- is that correct?

If so:

1. How good are your spacers? I have seen a few shoddy ones that are off in thickness by a fair bit -- not 15mm thick all the way around. If so your wheel alignment will never be right. Are they hub centric? Are they installed correctly?
2. What did you align to, USA or ROW specs? If you have the USA sport suspension the specs are the same as standard. But if it is ROW, the specs are different. Did the alignment shop realize you had spacers on? Did they have the correct specs?
3. Did you replace the lug bolts with longer ones when you installed the spacers? With 15 mm spacers you should be using 60 MM lugs I am guessing. Or they could be spacers with lugs attached?
4. How old are the tires? Wear on the inside only is usually a sign of an allignment problem negative camber. If you changed tire pressure to get more even wear and the tires were really thrashed on the insides, that could cause the vibration.

I would probably do the following in order followed by a decent test drive:
1. Remove a few lug nuts to ensure they were 60mm and have the cones. Then retorque them all to 96 FT-LBs. Torque every other bolt till all five are done -- first go to 80, then 85, then 90, then 96.
2. Remove the spacers -- fronts then rears. 15mm in front are pretty thick (IMO) -- I think 5 or 7 are more common with a stock wheel.
3. Realign and rebalance all wheels. Ensure the appropriate specs are used for the suspension ROW or US Sport.
4. Check/replace the front tires.

Tire rack has the linked chart that is more detailed with a few more options ... steps 1 and 2 above are free so what the heck (unless you need new lug bolts)

http://www.tirerack.com/images/tires/vibechart.pdf

Hope this helps.
ATB,
Tom

[Stunin_Stud]

I got my spacers new so they should be ok. I have the 60mm bolts, I havent had the car alligned yet because it seems to tract straight, and it came with the us spec M030 from the factory. my front tires were used for about 3 months on a mercedes and i put them on when i put new ones (same brand and rating) in the back. I think the inner wear is because of over inflation. when i first had the car it was inflated to 40psi from the tire shop, I noticed it rode like crap so i deflated it to 33psi all around.

speaking of riding bad, my car is really stiff compared to other boxster's I have driven.

I think its the tires and ballancing since i hear our cars are sensitive to them. Im gonna get the fronts and the back ballanced this week.



hey Blinkwatt....yea I dont go on 6speed much but my rear diffusers are the gemballa/strosek ones which i realized look the same. The side skirts are OEM aerokit 1. They were impossible to find and totaly out in the US. I got hooked up and got both sides new for 500 bucks shipped(new) from germany, the diffuser was 203 bucks but i got it used. I got my gemballa front bumper from usher in atlanta. the lines from the lip on the bumper to sideskirt to the diffuser match so thats why i got it. The front bumper looks like the boxster special edition.
how is your car now?

[blinkwatt]

Originally Posted by Stunin_Stud

how is your car now?

lol,it's in San Jose in pieces.........I'm currently in the middle of butting heads with the insurance company.

I can't wait to get it back! It's going to be one very fast drive back to Sacramento.

[Bambino Don]

I have had the exact same problem and it was a really bad at 70-75 infact it was really annoying, my front tyres were at 22psi and 24psi, i whacked the air into 30psi as per manual, (im currently 17" box S) and it was better but still not fully gone. I think there is a reason, my wheels were all balanced at OPC and i mentioned this and they found no reason.
mine is an 02 with 31k miles on the clock, never been crashed and full porsche centre service history. so there must be a reason,

James