CAMARO6 - View Single Post - Help, looking to quiet LT headers and cam

cmitchell17 · 10-19-2020, 01:08 PM

Does anyone have a picture of what the stock non NPP muffler looks like? I wonder if its the same dimensions? I would really like to see one cut open.

Also I believe there is a lot of sound reduction when revving at idle from NPP to non NPP because the valves are calibrated to be open when the car is not moving so it will be loud when you rev it and people will be impressed, but then close while driving along normally.

I have tried to change the valve positions around with HP Tuners, but I mostly found that there is no in between, its either open and obnoxiously loud at WOT, or closed 100%. There is something about exhaust that sounds good below about 60% throttle, then once you go above that at WOT, the sound quality just turns awful.

10-19-2020, 01:08 PM	#27
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,213	Does anyone have a picture of what the stock non NPP muffler looks like? I wonder if its the same dimensions? I would really like to see one cut open. Also I believe there is a lot of sound reduction when revving at idle from NPP to non NPP because the valves are calibrated to be open when the car is not moving so it will be loud when you rev it and people will be impressed, but then close while driving along normally. I have tried to change the valve positions around with HP Tuners, but I mostly found that there is no in between, its either open and obnoxiously loud at WOT, or closed 100%. There is something about exhaust that sounds good below about 60% throttle, then once you go above that at WOT, the sound quality just turns awful.