the quickest/best/most logical solution would be to add twin turbos. the turbochargers will quiet up the exhaust quite a bit and get you a real nice appealing sound out of the exhaust that you will love.

 

yes much cheaper than a motordyne ypipe

 

The round things on y-pipes are the flex sections. They allow the pipes to flex.

And I don't think there is any y-pipe out there that has resonators in them, except for MD's y-pipe.

From the looks of the GTM test pipes, they seem to be 2.5". I may be wrong, but that's judging from the pics..

If that's the case, then you have:

2.5" test pipe >> 2.25" oem y-pipe

That probably why it is rasping so bad..

 

gone to an exhaust shop and they say they can install some resonators on the exhaust for me and that should help the rasp (hopefully)

 

HFC's also have RASP just not as bad.

 

hmmmm on the inside of my car the rasp is crazy loud, but on the outside it doesn't seem too bad. but you can def. hear a little rasp.

 

Have you checked for exhaust leaks?

 

that's really good point ha ha ha ha

 

On our test car, the rasp was only "bad" when it was cold, once warmed up it sounds pretty nice actually - but what sounds nice to me could be annoying to others.

Are you sure you don't have an exhaust leak? As Tony stated that could be the cause.

Test pipes are always a little raspy, but shouldn't be as bad as you are describing.

Hope this helps, let me know if you need anything.

-George
GT Motorsports

 

Think I read in this forum, that rasp will stop after going FI.
Is that right?
coz I have it on my topspeed n1 3" and wanna go FI-hr. I hate rasp

Alex

 

Turbos cut down rasp in a very big way. And they do sound really good.
Its a totally different sound from NA.

 

I agree with you there but have you drove around in the z up to 3k rpm from 1-2 gears? That's where I hear the rasp can't hear my exhaust.

 

I know the exhaust wrap thing sounds strange, but I read on the G-37 forum where a couple guys had the same issue with that rasping sound and they said they wrapped it up and it went away. Could be a cheap fix.

 

What do I wrap?

 

+1

and: another noob question: does my exhaust lose some loudness after going F/I??

Thanks Alex

 

Sorry, but I'm not sure exactly. No one was too specific about that. I would assume just the HFC or test pipe section and maybe cover the flanges? I honestly can't promise this will work but like I said, it could be a cheap fix and others say it does work.

 

You would have the wrap the test pipe. That will only act as a sound deading on the tp. The rasp that carries through the exhaust will still cause rasp sound.

 

no worries, i removed my test pipes trashed them, and ordered a HKS high power exhaust

 

you should sell them to me