j09333

RPM niddle is shaking alot at high speed.
Higher the speed, worse the shaking.
Under 200km/h, using 5000-9000, niddle shake is visible but not violant.
Over 200 km/h, it gets worse, and shakes alot, more like 100 rpm diffeneces between shakes.

I did wheel balance and it is not the problem.
No steering vibration but more like car is shaking.

Drive shaft? Hub? I track this car pretty hard with pro driver.

Some of you know that my car had transmission service recently.
It shaked before the transmission change.
It all started when I put new tire on.
Tireshop admited they balanced my wheel wrong at the time because the machine were off spec and recalibrated afterwards.
But I did 3 or 4 track days with this wrong balance already then.
Because the tire had so much rubber debris on it and can not be balanced or road forced because of it.

So, it had wrong balanced wheel and was shaking.
However, after transmission change and new tires, it still shakes.

I thought new tire and right balance could take care of it and it was wrong.

Shaking is far less obvious and noticable with new tires but it is there.
Wrong balanced wheel did a part but something else was also wrong at the same time maybe.

So, please help me on this one.

montoya

The RPM gauge is just a fancy voltmeter- the signal comes from the ECU picking up a crankshaft sensor (or similar), not sure exactly on our GT3- but definitely the problem is with a sensor, not the tires or wheels.