Great reading this thread. I have a 2006 (997) carrera S RUF Kompressor.

Quick question to the knowledgeable community. Under hard acceleration above 5000 RPM the compressor belt seems to slip (compressor whine appears). As a result, I have upgraded the belt tensioner and done a supercharger overhaul, but the issue persists.

My theory is that the groves on the belt pulleys (both for crankshaft and compressor) are worn out.

Have any of you guys had this problem?

thanks!

 

I've not had that happen on my car, but it also only has 63k miles on it.

There is a pulley treatment some does that uses little pieces of diamonds or something that get bonded to the pulley surface. 928 Motorsports used to offer this for their supercharger kit pulleys, and have it on my 928 kit from them. They called it a grip coating or grip pulley or something - maybe you can find someone that can do that treatment process for you. If not, might need a new pulley from RUF or might actually be able to sandblast the pulley surface to make it grippier. I don't think the surface is hard anodized or anything like that.

 

Thanks for the quick reply Petza.

Interesting, will have to check that out.

For your information, when I put belt dressing on the compressor belt, the problem goes away for some short period of time before it reappears.

I know that the belt is not supposed to slip under hard acceleration so I think the groves on the belt pulley are uneven resulting in the slip at high pressure.

Do you for some reason have the specifications for the compressor belt pulley?
And what is the specifications of the compressor belt on your car currently?

thanks!

 

With respect of dimension, groove depth, etc, Sorry, I don't.

 

Thanks again

 

hello Steinspi,

Happy you reach this thread so the small community of RUF R KOMPRESSOR owners can help can eachother gathering our experience.

First, would you share some details about your car and maybe a picture? I've seen you are in Norway. I'm trying to consolidate a list of all 997 RUF KOMPRESSOR in the world. So far I have identified 26 of them and I can now add yours. I am in France by the way.

Regarding your issue, you talk about a whining and a slipping belt.

RUF wanted the Kompressor to be as silent as possible, it was part of the specification givent to ASA group in Germany for building the supercharger. I haven't found the information whether the supercharger unit is a special model or it is part of the usual range of the manufacturer. Nevertheless it is not supposed to whine. Mine is very silent. I had a mercedes with supercharger as well and you could hear it. If yours is whining there may be a point.

As regards slipping supercharger belt, it was also the case for me. It is the reason of my thread here actually.
While I was driving quite hard, the belt slipped away from the pulley and got damaged.
The car is now at the garage and I should get it back in the coming day.
We were wondering with the mecanic why the belt slipped and few days back he told me over the phone he thought he had found the reason. He will told me and I'll share the explanation here.
I have several parts changed, I've bought most of the part myself so I can tell you what are the references.
There is a specific tensioner pulley with a kind of small shock absorber and 3 pulleys (a metal one and 2 plastic ones), I ordered this part to RUF in Pfaffenhausen. In my case the shock absorber was leacking and there was play in a pulley.
I'll let you know once I discussed with the mechanic.

 

I didn't know about belt dressing. Is it recommended? Petza, any thoughts about it.

 

Thanks DJ9XX, looking forward to hearing back after you have spoken to your mechanic.

I have previously swapped out the belt tensioner (ordered from RUF).
When you refer to the metallic pulley do you mean the pulley that is attached to the compressor?

Mine is a black 06 carrera s convertible. Manual gearbox with 120k km. Was shipped to RUF from factory to fit the kompressor kit.

 

Any updates from the mechanic DJ9XX on what was causing the belt to slip?

 

Yes I got it back and the car works now perfectly.
Well as per his opinion, the belt tensioner and the upper pulley were not perfectly aligned and it is has weaken the belt. Now they correct this issue I should be safe. Anyway I'll make sure in future the belt remains in good condition.

 

Belt dressing is usually just a short term fix and doesn't last very long. If you need belt dressing you have another issue, like a weak tensioner, pulley alignment issue, or worn belt.

 

Thanks for the update DJ9XX. Great to hear that your car operates perfectly now.
I have the same understanding regarding the belt dressing as Petza, it is only a short term fix.
As I have replaced the tensioner and belt the only thing left is the pulley replacement and alignment.

 

My pulley has a thin metal shim behind it. If you have all the bracketry properly mounted, everything should line up. I've adjusted my idler roller position a hair with a washer to make the belt run directly in the center.