Kraftwerks C38-91 and 85mm Pulley

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10-30-2015 | 12:36 PM

#71

Habitforming

Joined: Apr 2003

Posts: 3,243

Likes: 2

From: Northern KY

Quote:

Originally Posted by s2000442

Tts uses 81, 91 and 92 they all bolt to the plate. I have not heard of any tts kits with blower failures in U.S. Maybe some in UK?

Oh, good to know. I had thought they exclusively used the-92. I guess it's just that is the one all of you US TTS guys have.

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10-30-2015 | 01:53 PM

#72

agent

Registered User

Joined: Apr 2007

Posts: 485

Likes: 2

From: Tallinn, Estonia

TTS states that they use 81, 91 and 94 chargers

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12-22-2019 | 09:36 PM

#73

zanahale

Registered User

Joined: Jun 2019

Posts: 53

Likes: 14

Quote:

Originally Posted by The Machine

Leo, my issue was resolved in a nutshell by having KW install a new hub bolt. So far the car has been back on the road about 1.5 months and I haven't had any issues since. It runs great and pulls hard. I don't regret my decision going with this kit and I think the 85mm pairs nicely with the 91 blower. You are correct that rpm should be set at 8k with the 85mm pulley so just make sure it's not set any higher. Also pay close attention while shifting and getting close to redline as the Rotrex units do not like the rev limiter or over spinning the blower.

There hasn't been any conclusive evidence from KW yet about what actually has caused these bolts to break in the first place, but I'm hopeful that their R&D department is working on it. I'm very curious as to what the underlying issue may be, but at this time, my advice above is the best I can give to help prevent you from running into the same issue I did.

When you got your blower back with new hub bolt, did you put the car back on dyno? If so, how many pulls on dyno? I had same issue on mine (bolt broke on 5th pull on new kit) and just upgraded to C38-92 blower with 85mm pulley (working with Kraftwerks now on warranty).
I am about to have new blower installed in next few days. I am just curious if you put it through same paces on dyno? Mine is already 80% tuned after first one had bolt break, so I am kind of dreading putting new one on dyno and hitting rev limiter again only to see the pulley break off again....

Definitely going to verify belt tension myself as it was originally done by installer. Since I am upgrading pulley also from 90mm to 85mm, I am also going to make sure my rev limiter is set to 8k....probably start cutting fuel at 7900...not sure yet.

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