Vibration in the 80's
05-18-2004, 11:23 PM
#1
Vibration in the 80's
I've had my '02 turbo about 3 months now, stock suspension, wheels and tires. When I purchased the car, it rode a little choppy, with high speed vibration, which I attributed to flat spotted tires. Had the tires balanced and rims checked (OK) which seemed to improve, but didn't solve the problem. Putting some mileage on the car didn't make it go away either.
Bit the bullet, and installed 4 new tires. Car is smooth now except first mile or so in the morning. The problem is between 80 and 90 mph. On "certain" (most) surfaces, a slight vibration in both the steering wheel and the chassis is felt. Over and under these speeds, the car is smooth. Dealer won't test over 65, so no help here. Since it is minor and kind of intermittant, I can sort of live with it. The more serious problem (for my license) is I tend to cruise at 90+, which is where the car feels best.
My question is, are these car especially sensitive to road surfaces in this speed range? Anyone with insight on what might be going on here?
Bit the bullet, and installed 4 new tires. Car is smooth now except first mile or so in the morning. The problem is between 80 and 90 mph. On "certain" (most) surfaces, a slight vibration in both the steering wheel and the chassis is felt. Over and under these speeds, the car is smooth. Dealer won't test over 65, so no help here. Since it is minor and kind of intermittant, I can sort of live with it. The more serious problem (for my license) is I tend to cruise at 90+, which is where the car feels best.
My question is, are these car especially sensitive to road surfaces in this speed range? Anyone with insight on what might be going on here?
05-19-2004, 03:51 AM
#2
Three Wheelin'
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I think some vinbration and the steering wheel click (slight systematic side to side movement) is normal due to most roads having a slight angle to one side or another (e.g. left lane is tilted to hte left) and imperfect road surfaces...
05-19-2004, 09:41 PM
#3
Instructor
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Two things.....
1. Balance the tires using a road force balance machine...its more expensive but might eliminate the vibration.
2. Porsche NA knows that the Pirellis can be square literally. Also flat spotting can occur due to the cars sitting for a long time i.e. over winter...it's pretty hard to flat spot a tire with ABS.
I had this same problem and they replaced them for free with Conti's. The problem went away but I wasn't too impressed with them......utlimately I switched to Michelins.
1. Balance the tires using a road force balance machine...its more expensive but might eliminate the vibration.
2. Porsche NA knows that the Pirellis can be square literally. Also flat spotting can occur due to the cars sitting for a long time i.e. over winter...it's pretty hard to flat spot a tire with ABS.
I had this same problem and they replaced them for free with Conti's. The problem went away but I wasn't too impressed with them......utlimately I switched to Michelins.
05-19-2004, 11:11 PM
#4
Rennlist Member
Sports cars with wide tires will (wander) follow irregularities in the road surface but this is different than vibration. Did the service people check the wheels carefully for "trueness" by spinning them on the balancer. Tires and wheels have to be reasonably true.
Since this is at certain speeds could this be an all wheel drive issue?
How about getting a ride in a car like yours and see how it feels (or get the owner of one like yours to ride with you).
Since this is at certain speeds could this be an all wheel drive issue?
How about getting a ride in a car like yours and see how it feels (or get the owner of one like yours to ride with you).