Shaking at 150
 

Hey,

I got a 02 Boxster 95,000km and Ive been experiencing some shaking at higher speeds usually always at 150km but some times it shakes sometimes it doesnt I dont get it. I have fairly new tires and recently did a wheel alignment and wheel balance on all rims and still same problem. Also another problem is I sometimes feel the road more then other days, like when going over bumps or rough roads car feels like **************** as if the shocks were broken and other days no. Like the car has its good days and bad days and its starting to piss me off. Any ideas? Ive heard about the Lexus switch but honestly these cars cant be that bad.

hey yea I experienced similar problems too. Make sure the wheel is properly ballanced using a Hunter roadforce ballance machine. These cars are very sensitive when it comes to ballancing. if the geometry of the wheel changes in the slightest way you will feel shaking at freeway speeds. my car rides hard too but i have had people check it out and they say thats how it is. When I experienced shaking I ballanced my wheel 3 times until it was done right. another time I relized my hubcentric spacer was slightly loose so I tightened it and it got better.

so get the front wheels ballanced at a good place.
if you have spacers make sure they are tightly secured and all screws are in place.
make sure your wheels are not bent or missing a chunk due to curbing, and check your tire wear, and make sure your bolts are securely on.

good luck, I know its frustrating.

I would try slowing down. That speed belongs on the track, not the road.



:D

I think he was saying 150 Kilometers per hour, not miles per hour. :)

150 Km/H is about 93-94 MPH which is pushing being unsafe, on public roads. I think the shaking is probably from wheel balancing. :cheers:

To those of you who are not living in province of Ontario in the country up north called Canada, if you're doing 150km/h or over there is a "street racing" law that went affect last year that if you were caught the cops are allowed to tow and impound your car on the spot with license suspension and not to mention heavy fines. :eek:

I'd say it's wheel balancing too. You need to take it to a shop with a decent tire balancing machine.

Did he mention this is street driving v. track?

You may also want to be aware of the outside temps. He is in Canada and some of the ultra high performance summer tires are very unfriendly to cool temps. They can flatspot until good and warm and I've also heard of some other roundness and wobbling issues with undertemp high performance tires. I took a set of Bridgestone S03's to Ohio in December, once. No snow, but I think I was half way back to Florida before the flat spots finally went away.
A shock issue could explain the ride harsh/ride okay instability, but I've never heard of shocks causing a shimmy situation. Alignment can and uneven tire wear and/or scalloping from poor alignment can definitely cause speed related tire vibrations.

Ofcourse these speeds only belong on the track which I did very safely with a helmet on.