Buzzing/rattling after clutch stop install

[1descending]

I just installed the clutch stop from Burger Motorsports, and removed one of the padded discs from it so there's only 2 discs instead of the 3 that came on it. But since installing it, I have noticed a buzzing or high speed rattling noise when rev matching downshifts. With the clutch pedal pressed fully, when I give the throttle a tap to rev match, I can hear a buzzing or rattling type noise.

I've tried to reproduce this in neutral while parked but cannot, it seems to happen when revving the engine with the clutch in while moving.

My first thought was maybe the clutch isn't quite fully disengaged and what I'm hearing is some slight clutch chatter. But wouldn't I be able to hear that when revving the engine in neutral while parked with the clutch in?

Any ideas?

[1descending]

After more investigation, I don't think this has anything to do with the clutch stop install, but I just noticed it because the weather is coincidentally good enough to have the windows down.

The rattle comes from the front of the car when I give the throttle a sudden tap to rev match. But it does not occur if I give the throttle a softer, more gradual push to rev match. Still cannot get it to occur when stopped, in neutral, both with the clutch engaged and disengaged.

[ShocknAwe]

Rattle when rpms fall or build? Please post a video if you can.

[1descending]

Its tough to get a recording of any sort because I can only get it to happen while driving and not while stationary.

But the rattle is when the revs build. It goes away as soon as I let off the throttle.

[ShocknAwe]

Dunno then, was going to say wastegates but if its when on the throttle I'm out of my comfort zone answering that and don't want to cause false alarm with an improper suggestion.

Good luck and really, a video will help, even if you have to get a passenger to shoot it for you.

[1descending]

Yeah I'll try to get some kind of recording this weekend. I was also concerned about it being wastegate rattle but from what I've seen, people with that issue have been able to reproduce it easily just by revving the engine in neutral, and the rattle occurs when the revs fall.

[edisapimp]

Does it sound like metal on metal? Does it sound like it's coming from the engine bay or from underneath the car? Can you figure out which side of the car it's coming from?