Hey guys. Just had the exhaust done on my 08 g35xs. I now have top speed pro-1 resonated test pipes into 2.25 in. tubing. Replaced the y-pipe with custom x-pipe crossover leading back to magnaflow street series quad tipped mufflers. It sounds great when idling but when you step on it it's extremely loud and raspy. I hate the rasp more than anything. Sounds really ricy. Any suggestions on how I can eliminate the problem???? Thanks for any imput.

 

try going back to stock cats or at least HFC. that should alleviate the problem a bit.

 

as jersey said take out the test pipes and replace with high flow or stock cats. the high flow cats will have some rasp but it wont be as bad. when i had high flow cats it was raspy at 3K RPM till about 3.5K RPM. otherwise sounds fine.

 

Thanks guys. I already sold the stock cats so i might try the hfcs. Also thought a magnaflow resonated x-pipe might help too instead of the straight x. Anyone have one installed? How does it sound?

 

Motordyne makes a resonated Y pipe.
Most of your rasp comes from your test pipes. Even though they are resonated.

I'm dealing with same issue. My setup is Fast intentions HIFLOW cats 2.5 to 3 inch Y pipe and Exotic speed exhaust.
I'm considering installing magnaflow 4 inch resonator (3inch inside) in the Y pipe to reduce the rasp.
Motordyne is doing it on their Y pipes, I'm willing to bet it will fix the rasp.