Quote:
Originally Posted by Beedub
Sadly..... I think damage may be done to the s/c unit..... metal on metal shouldnt be happening, loose pulley or not :-(
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To be clear, I have no objective indication that there is really metal scraping. I'm pretty convinced at this point that the screech is in fact just the belt slipping on cold startup, not the internals of the S/C. Beedub, the video I posted of the screech is a pretty good capture of what it sounds like, and you don't figure that's from the S/C itself do you?
The actual S/C whirs like a finely-tuned jet engine at engine speeds over ~1500RPM. Below that (mainly below 1200RPM) it can be a little rattly as everyone describes to be normal. My suspicion is that the individual power pulses are more distinct and separated at those engine speeds and it causes the gears in the S/C to knock together a bit; a compromise since they are truly designed to run smoothly at extremely high RPM.
Obviously if there is still a screech with the new pulley and proper tensioning, the S/C will be to blame and have to be replaced, but I think that is extremely unlikely to be the cause or to be necessary. Some have implied that these are really fragile pieces of equipment, but it's a freaking vortech supercharger--a mechanical beast that isn't going to be junked by a little bit of belt wobble on less than 5 cold startups I've done. If it really were that delicate, I can't imagine it withstanding a single day at the track, proper belt tension or not.
The car is already in the hands of HG Motorsport who plan to not only replace the pulley and belt, but also at least diagnose the BPV whistle.
Last night I drove across town at night with the windows down...little traffic, pretty quiet out. It's the most rewarding experience I had with the kit yet and gave me some encouragement that the issues will be sorted. Perhaps my favorite thing about the noises the kit adds to the car is when decelerating to a stop--as the engine sweeps down in RPM, especially from 2k to idle, it arguably sounds like a gas turbine is under the hood! :-D It sounds very sophisticated and exotic; I'm sure it will turn heads over time as drivers or pedestrians notice a sound they've never heard of coming from the car that definitely exudes performance, unlike the damn BPV whistle
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