Vibration when revving

GreatWhiteKAC

Enthusiast
Joined
May 26, 2024
Posts
5
Reaction score
0
Location
MN
Took the Gen 5 for a car was today after a night of somewhat spirited driving. I did a launch or 2, and a couple 20mph pulls. Nothing too crazy.

7k mile 2015 GTS

I should preface this by saying I have Capristo Valved exhaust. So, I can close the cutouts and make it very quiet.

However, when I rev the car with the cutouts open (so full loud), as the revs come down to 2k rpm and below I get a vibration that sounds a phone vibrating kind of? Like loose thin metal vibrating. Maybe a heat shield?

The strange thing is it only does it when the exhaust is loud. When I close the cutouts/valves it doesn’t make the noise when I rev the car! So that would make me think it’s not anything mechanical like driveshaft. As it doesn’t do it when the car is driving. Only when the clutch is in or I’m stopped in neutral and I rev the car… and only on “decel”… so, even if I rev the car to 5k rpm, it won’t make the noise at 5k, only as the revs come back down to 2k rpm or so and then it’s a quick BZzZzZZZzt

Any ideas?
 
Top