awaisrad

I have a 2015 GT3. Stock wheels, pirelli P zero trofeo R, -2 camber setting all 4. Wheels balance 2 times. Giro discs, stock pads, with vibration that progressively worsens 128 to 150mph on. Any thoughts.
Desperate.

MileHigh911

Bent rim.

mwar99

Rubber in the wheels?

skippyBKR

That's easy - knock your wheel balancing weights off your rims.
If you are seriously tracking your GT3 you will find the tyres (sorry, tires) will move on the rims under extreme braking (and hard launches).
Still don't believe me - get a paint pen and mark the rim and tyre at the same place and check it after a hard session with the tyres up to temperature. You will be surprised how far they can slide on the rims.
When you have an already balanced rim move on the tire, the result can be horrible vibrations at high speed.
I've tried putting the tyres on with no "goop" and a few other products, but they still move. Such is the grip of these new tyres!
So, save the money and don't bother wheel balancing and you'll cure the vibrations.
I haven't balanced race rims for years

Macca

Interesting observation Matt. I didnt realize this to be the case, though I have no vibration to speak of I will experiment with a marker on the rims on my next track day :-)

P.S. Off topic - but what are your plans for the next Targa? Still running 991 GT3?

Stgrt

Deleted.

kyrocks

Or get wheels with knurled beads and the tire stays on much better.

awaisrad

the rims are brand new Porsche

i sat in my friends gt3, not an ounce of vibration at the same speed

mdkim

You also could have lost weight(s) if you didn't tape them.

My tires would also rotate badly rendering any balancing worthless.

LastMezger

Rumble strips? ;-)

skippyBKR

Most definitely Macca - with bells on. But Targa High Country early November coming up first.

skippyBKR

Most definitely Macca - with bells on. But Targa High Country early November coming up first.

skippyBKR

Did anyone else hear an echo?��

awew911

This may be the cause. Look for signs of prior wheel weights on the wheel (residual adhesive). I use the aluminum duct tape to keep the weights in place. Under hard braking, the wheels get hot enough to melt the adhesive and bye bye weights... They literally fall off (or worse - fly).

I wouldn't remove the weights altogether though. Ever notice the weight placement is usually on the opposite side of your TPMS sensor? The TPMS sensor plays a larger roll in upsetting the balance of the wheel than the rotation of the tire (which is relatively uniform in its construction). My tires rotate on the wheels throughout the day with no noticeable impact on vibration. Removing the weights may not have the effect you are looking for if you have the TPMS sensors.

Perhaps it is something else.

skippyBKR

[
I wouldn't remove the weights altogether though. Ever notice the weight placement is usually on the opposite side of your TPMS sensor? The TPMS sensor plays a larger roll in upsetting the balance of the wheel than the rotation of the tire (which is relatively uniform in its construction). My tires rotate on the wheels throughout the day with no noticeable impact on vibration. Removing the weights may not have the effect you are looking for if you have the TPMS sensors.

Perhaps it is something else.[/QUOTE]

So, when your TPMS compensating weight has eventually moved around 180 degrees to the same spot as the valve stem - isn't that twice as bad as no wheel weight at all?
I'll stick with no wheel weights.