First off, I'll start by saying I've installed this and it sounds fantastic no matter where the revs are. However, I am having one slight problem that I haven't been able to resolve and was curious if any other members that have installed the same issues have been able to remedy it.

Anyways, the issue:

If I rev in neutral, it sounds like there is a rattle or leak coming from the h-pipe but only when the RPM's are on their way down. It happens exactly at 2-2.5k on the way down after a rev. While driving there is absolutely no rattle or leak sound, just Borla greatness. (I've even tested this with someone outside the car after a drive-by where I let off the throttle around 3k and coasted by them) I had the car lifted and tried to make sure it wasn't contacting the frame and rattling there, but it wasn't. I've even adjusted and re-tightened clams to the manufacturer specs, but the noise is still present in neutral while revving.

I have found this thread:
https://my350z.com/forum/showthread....rattle+OR+leak but I don't think quite relates to my issue since my problem only occurs while standing still. Again, while the car is moving there is no issues with it.

 

My stock system does the same thing, it may be resonance within the pipe and at a certain point the contacts may rattle.

I wouldn't worry about it, but you may try welding the contact points.

 

from your description it sounds like you are experience the Borla Hiss. Some describe it as a rattle snake affect, but i noticed it once i added my HFCs. I see your running Berks HFCs which allow a great deal of oxygen flow over stock causing a hiss. Dont feel bad, if you had test pipes that is when and where your rasp would produce. It damn near sounds like an exhaust leak in fact i've checked my gaskets a few times because of the hiss at the beginning.

-if this is not what you are hearing, and it is more of a Metal to Metal rattle then PM me and i can shoot you in a couple different directions i had to take when eliminating rattle.

If you ever have problems with your H-Pipe on the Borla set up, please take advantage of the 1,000,000 mile warranty, they WILL send you a new H-Pipe if you prove to them yours cracked and you purchased it new. They don't even ask for the old pipe, they just send it out. Excellent choice of exhausts btw, ENJOY!

 

Yeah, it's kinda like the rattlesnake sound. The gaskets were also the first thing I checked when I noticed the problem. :P (I did notice a small amount of condensation forming on the bottom of the gaskets on the HFC -> Exhaust, but I never could find an air leak from them. The bolts are torqued to 40 ft. lbs. and I'm afraid to make them any more tight)

I guess I won't worry about it then, as it works perfectly fine while driving. I usually drive with the radio off and windows down now. It sounds great!

Anyways, I appreciate the input guys, thanks.