Stillen S/C Si trim noise
 

Hey guys, hoping for some feedback on this noise my newly installed s/c is making. It's perfectly rhythmic, and speed increases with RPM to about 2k, above which it either disappears or is drowned out by other noises. It's coming directly from the V3 Si trim unit, and seems to get louder and quieter randomly. I've heard of gear lash, but the videos I found showing this didn't sound quite the same.

Here's two videos trying to capture audio from inside the car and from under the hood.

https://streamable.com/s/3x6zc/misnqz

https://streamable.com/s/u112n/ppcslr


Any thoughts: Just gear lash? Bad bearing? Loose Pulley? Thanks in advance!

Mine made the same noise before I had it rebuilt with the high performance bearings and the higher performance impeller. Now it's much quieter.

Are you seeing the expected boost?

+1 Case by case could be different. Do you have a boost leak and are you seeing the correct amount of boost psi.? I had this same issue with noise from my V3 si trim and it turned out my bearings were shoot and I had to send my V3 si trim unit to Vortech to have new bearings installed just three years later after installation you have to pay to play.

Haven't gone WOT yet; I just got the kit on and I'm having it remote tuned by SebZ. I was hoping someone knew what this was and make sure I'm not about to WOT my s/c into pieces.

I can understand that. The noise depends. Let's know the boost under WOT first. BTW, are you overspinning it?

It looks like he has the stock Stillen kit.

Stock pulleys, just intake piping delete and Si trim upgrade. I'm making my first WOT pulls this weekend, will definitely let you guys know.

Got my first WOT pull in, and boost is in expected range (peak ~10.5psi @5000DA). I also noticed the sound is a lot louder when it's cold, and seems to go away when the injectors turn off in decel.