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Rotrex failure

Old Apr 17, 2023 | 11:20 AM
  #21  
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Yes, thanks for posting the outcome! I'm running a C30-84 unit.
Cheers, Joshua
Old Aug 23, 2023 | 07:34 PM
  #22  
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Originally Posted by Soy
late follow up but i think this story needs a conclusion,

Sent the Rotrex back to TDR to send to Rotrex for a warranty claim. They got back to me about 5 weeks later and it turns out it was a manufacturing defect. Something about the main bearing that holds the pulley failing and that it was a known issue with that batch of superchargers. may of been kick started by the bad supercharger bracket but thats speculation. Rotrex claims that current c30-94's dont have the same weak bearing design. frustratingly though Rotrex denied the warranty claim since I was 2 months out of warranty. TDR felt for my case and sold me a new unit with the fixed bearing design at cost. overall i think this was all a string of bad luck. I dont suspect this new charger to give me any issues. Ive had it installed for the past month and ive put around 300 miles on it. its substantially quieter and hasnt popped a belt. Really on me for not recognizing the belts popping off and louder then usual noise as unusual.

car is fast again and i am happy again


Do you happen to have the origional information and serial number of your charger? I purchased a c30-94 in December of 22 and just got it all installed a couple weeks ago. I am waiting for a dyno day and the MS3/FF sensor so I am not driving it too much but I would be curious to know what the diffrence in our serial numbers are.
When did you purchase your kit?

I am local to TDR (45 Minutes) and Dan has been a great guy to deal with, I have a cold belt squeal that will go away shortly but I also found some lateral play on the tensioner pulley (plastic/phenolic) and I may look to source a metal pulley. There is an incredible amount of heat generated under there and I want to know some $10 pulley is not going to grenade at 7k and destroy things.

Thanks bud!
Old Aug 24, 2023 | 09:26 AM
  #23  
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Originally Posted by 54lariat
...but I also found some lateral play on the tensioner pulley (plastic/phenolic) and I may look to source a metal pulley.
I used a timing belt pulley from a 2009 Elantra. See this thread https://www.miataturbo.net/superchar...igh-rpm-97147/

Old Aug 26, 2023 | 04:04 AM
  #24  
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Timing pulley bearings are typically not rated for the RPM they will see in a SC application.
Old Aug 27, 2023 | 10:03 AM
  #25  
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Harry,

I'm having a hard time visualizing that. I'm not agreeing or disagreeing, just saying I'm better at visualizing ****.




That's the pulley in question. I never once thought of an rpm difference in application. The way I figured it, timing belt pulleys are over-engineered since it's a real chore to replace one. It's got way over 100 track days on it and it seems fine. But if it did go bad, it's readily available nearby and easily replaced. Also, if someone wanted one slightly bigger or smaller, a few minutes on napaonline would come up with alternatives.
Old Aug 29, 2023 | 12:25 PM
  #26  
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These are all fair points; my comment was due to the fact that I have seen a few puking lubricant through their seals sooner than "expected" when used as SC tensioners, which is due to exceeding the RPM "limit" of the bearing. Easy to visualise as well; both the timing belt and the SC belt are being directly driven by the crank, but the SC pulley has a much larger diameter compared to the timing belt crank pulley. Max tensioner bearing RPM would be crank RPM x (crank pulley OD / tensioner OD).
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