Hey guys,

I recently purchased a 2010 GTS (a nice companion to my 997.1 turbo) and put the Pirelli 21" scorpion ice on the OEM rims. Anyways, after the initial install, I felt the car pulled a bit to the right. I returned to the shop and had them swap the front tires. It seemed to remedy the problem as I drove a bit more. However, when driving at higher speeds ie over 70mph I feel the steering wheel vibrates. It feels different than an off-balanced wheel because at higher speeds, it seems less smooth. I returned to the shop today and the guy told me the tires aren't going to be as smooth as the OEM tires and shouldn't worry about it. Anybody else have these issues with their 21" snow tires?

Thanks in advance.. and I love the GTS!

 

I have the 20in version and have no issues. Just put them on about week or so ago. But I installed and balanced them myself. I've purchased wheels before and have had the shakes. Would just put them on the balancing machine and do it myself. Maybe the shop needs to recalibrate their machine.

 

a little trick to keep the vibration down ... when you change the wheels torque the wheels to 118lbs (not a typo it is spec) while the car is in the air. It willl center the wheels. Trust me it works. Most people torque the wheel to something like 94 lbs (like an older 911) and they do it when the car is on the ground. So what happens is the wheel does not get centered perfectly. if you do it when the car is off the ground and tighten to spec, I think you will be surprised. It got rid of my vibration completely. I switch to winter tire setup, and no vibration with this method.

 

Great suggestion, maybe they just airgun them badboys on there in a circular pattern. Also give a cleaning to the mounting surfaces. If need be.

Hopefully you can do these suggestions on your own. Otherwise see if the shop will do it for you. It's not always the easiest thing to tell a shop what you would like them to do.

 

If you don't Road Force Balance the wheels this is what happens. Get to a Hunter machine asap

 

The road force balance machine is awesome but I personally don't use one and never had an issue. I would love to have road force at my disposal but I don't. Anyway the biggest problem is when you need more then 1oz in an area. Spreading more then one oz across the wheel with more then 4 1/4oz weights is ridiculous. You just chase the balance and have weights all over the place. If you don't have the proper weight then just stack them when needing more then 1oz.

I know you guy's have had or seen rims with long strips of weights all over them.......

 

Thanks for replying guys. I just came back from driving on the highway to get a better sense of what is going on. Seems like the vibration is much more prevalent at ~75mph. So, I'm going back to the shop tomorrow AM. I should ask them to torque to 118lb while the car is in the air? Does the pattern in which it is torque make a difference to ensure the wheel is perfectly centered?

 

I guess if your a wheel whisperer you could do it but 99% of technicians cannot get it right on a Cayenne, the geometry is just to complex. RFB should always be carried out on a Cayenne.

 

I had one set of wheels RFB and the winter set was not. They both caused vibration at 55 - 80 mph. Then tried the torque in the air technique and the vibration all went away with both sets of wheels. I am a big believer in RFB as well, but I think things need to be lined up on these cars. Also I think some cars are more sensitive to this than others. Mine seems xctremely sensitive. I even went and bought new wheels, tires, and RFB them .. and they still vibrated. I was going to sell the car because it bothered me so much.

 

This is probably a stupid question but is the wheel center bore hubcentic? Or is a ring being used?

 

You might be on to something there if those are aftermarket wheels. If they are not OEM, then you might be missing a hubcentric ring.

Although if you had none installed at all, the vibration would be something fierce.

 

Rereading the original post it looks like they are OEM wheels.

 

this is a known cayenne issue at around 70, hunter road force balance, run a little more pressure 40 psi, mount in the air and just maybe you will get lucky.

 

Woops.. missed that part.

In that case, I would agree with CueMaster 100%

 

Just wanted to update you guys.

1) brought gts back and asked them to rfb all 4 tires. They found one of the wheels needed some help. Now, things are better but definitely not as smooth as the summer tires. It would have been so much easier had they rfb all four from the beginning. Thanks for all the input.