I recently had a custom catback exhaust made for my g37x coupe, the piping is 2.5 inches, its loud when i get on it but quiet at idle, how do i fix that? I think the stock resontors are still on! Would getting the same size resonator as the piping make a difference in the tone?

 

You could try these

Vibrant Performance .

I have the 2.25" ones on mine. Not sure how much louder they will be at idle.

 

Did it change the exhaust tone a lil bit?

 

I would say my exhaust got about 60% louder. I have a sedan with tanabes.

 

Would this make the exhaust louder if I'm completely stock on my sport sedan? If so what would it sound like??

 

It should get louder. I'm not sure how long the oem coupe resonators are.
I went from 18" to 12" resonators but mine is a sedan. so

 

Does it add rasp or is it deep? It's only $60 if it sounds good I'm in lol

 

No rasp. and no drone. you will get some rasp if you completely remove the resonator.

 

Any ideas how long the OE resonators are?