I have the metallic rasp induced by HFCs installed on my stock catback exhaust on my 08 G35 sedan. This is the rattling noise that occurs on high rpm acceleration. Will swapping the Y-pipe (for example, to the Ichiba G37 Y-pipe ) eliminate this noise?

 

Try it and find out.

 

^^^^not a helpful answer.

 

no sir in my experience it increases rasp tremendously. My setup is HFC's and tanabes, i put ichiba y pipe and cringed it was so disgustingly raspy. It may have been due to the actually ichiba y pipe and a different brand may have been less rasp. i just know im waiting for the tanabe y pipe and mid pipe to be released so i can have my full catback.

i just read a you have a g35 sedan so it may be different

 

I agree with Chris. Adding a Y pipe or even a full cat back tends to make it more noticeable not less. I've read that wrapping the HFC with header wrap may help but haven't tried it.

 

OP.. what kinda HFC do you have?

 

Would an X pipe setup eliminating the flex pipes, get rid of the rasp? The FI exhaust is setup this way. Also I have Berk HFC.

 

Rasp FTL. One of the reasons why I just can't seem to pull the trigger on HFCs.

 

Is this rasp all the time? I got really nervous after installing my catback exhaust...put it on and was very happy with it. From the drivers seat it sounded great. Decided to do an "after" video yesterday and when I heard the video I was SCARED! Sent my wife off in it down the street and there was a horrible 92 honda sound coming from the car. Thought about it (was really pissed) and thought that maybe if you drive for a few minutes it just needed to warm up. Well, sent the wife off again but she went around the corner for a few and drove for about 2 miles. She took off again and the rasp was gone and nothing but the sweet low tone coming out. So, make sure it's warm before you judge...No, this is not for HFC's but you may get the same result. ???

 

There is less rasp when the exhaust is hot but there is still rasp nonetheless.

 

No, changing your Y-pipe will not eliminate rasp. The only chance you have on eliminating rasp is adding a resonated pipe or exhaust system.