Elbron37

Hello, 2 days ago I installed an after marker y-pipe (1320 y-pipe) on my 2011 g37x sedan. And it sounds like *** from underneath....
sounds like a leak or rasp but it’s only coming from underneath and not so much from the exhaust tips. Has anybody experienced anything like this?
Im guessing it’s because the outlet diameter of the y pipe which is 3inch and the inlet of the resonators piping is around 2inches, but I could be wrong. What should I do to get rid of the raspy sound?
btw my exhaust set up so far is: 1320 resonated test pipes, 1320 y pipe, and a hks axle back.

Thank you!

ryanwhite74115

Is the mid-pipe OEM or aftermarket? If aftermarket, resonated or non-resonated?

Elbron37

OEM mid pipe

Dzionassi

yes, it will rasp with aftermarket y pipe. Two Vibrant 1792 in place of flex pipes should fix it.

Good luck

Elbron37

So the problem is with the flex pipe and not the size of the pipe?

Dzionassi

i just gave a place were resonator could be installed on your setup. Yes pipe size and test pipes is a factor in your case.

RMB5190

iTrader: (2)

It's the OEM mid pipe. The drastic change in pipe diameter is what's causing it. Either have a shop fab you up a similarly sized mid pipe or you can go the resonator route. I ran into the same issue after installing test pipes. Even with the Top Speed Y- back, the 3'' outlet to the 2.35 inlet of the Y-pipe sounded horrific.As I had already 'upgraded' the mid pipe I went the resonator route.

Elbron37

What’s the resonator route? What should I tell the muffler shop?

afrayedknot

iTrader: (3)

Where along the exhaust did you choose to install the resonators?

RMB5190

iTrader: (2)

Install your choice of Vibrant resonator. You want to have the shop install them as close to the motor as possible. They should be installed on the Y-pipe either at the flex section after the cats or you can squeeze them right after the flex section if they are short enough. I went with the Ultra Quiet set-up. Might not be for you if you like your car loud.

My car is pretty mellowed out since installing them but I can post a video and pics of where mine are located if you'd like.

afrayedknot

iTrader: (3)

Elbron37 - So there was no rasp when you had the test pipes paired with the stock y?

RMB5190

iTrader: (2)

There will be....It won't be as bad as an aftermarket Y-Pipe but it's going to be there.

Elbron37

Not at all, I got 1320 resonated test pipes

RMB5190

iTrader: (2)

Good choice going with resonated test pipes. Circuit Works (the ones I have) have an "anti-reversion" set-up which is not the same as resonated.