Yeah. I think what you're hearing is just the sound swirling around and/or trying to escape the resonators? That was my guess.. I think I kind of hear what you're talking about but I don't really notice it.

Armonster what Exhuast do you have. What you have I believe is just rasp. Not the hiss people are familiar with on decel around 3-4k

I just installed my ART pipes yesterday after work. My exhaust sounds great. It's not much louder from what it was previously, but it's definitely deeper. Thanks Tony!!!

I've got the OEM nismo exhaust. I don't know whether the hissing is rasp or not, but I'd like to find a way to get rid of it ASAP.

I have the HISSING sound on mine too. It's quite annoying. I'm also curiously about how to reduce or get rid of it.

One thing for sure, it very much depends on the exhaust it is connected to. Different exhaust parts react differently when connected to other parts.

Which exhaust do you have?

Just had them installed at Performance Motorsport. It literally took 20 minutes to get OEM cats out from the moment they popped the hood. The demon bolt aint sh!t for PM. I'm going to make a detailed thread when i get home, but in the meantime my quick impression is its louder than before but not much. The ART Pipes still need to break in so we'll see how they sound in a week.

Power, the top end has tremendously improved it simply hauls. The low end is brighter but i dont notice the torque increase as much as i did in my 350Z probably because it was auto. Regardless ive only driven it about 20 miles and all of it was highway. Detailed thread to come later.

Err...I've developed some crazy *** tin-can rattle from what sounds like the driver side. I know we cut the bolt, I saw them do it. It sounds very metallic, embarrassing, and loud.

Any ideas what this could be? It's a constant metal noise. I've recorded it. Uploading the video now.

Here's the link. WTF is this?

Video - TinyPic - Free Image Hosting, Photo Sharing & Video Hosting

I literally drove the car 25 miles to my girlfriend's, no noise. From there drove another 10 miles home, when I rolled down the windows as I was getting off the highway I heard the noise (it was DEFINITELY) not there before.

Can you get under the car to see what side it is on or what it may be?

I have the Boombop Shop CBE. It's a 2 piece slip in exhaust, no flanges. The exhaust sounds great with the ART Pipes. The hissing is noticeable below 4000 RPM. After 4K RPM its a beautiful sound.

I can try. But with the drop, it makes it much more difficult now.

Although it does sound more like driver's side.

Here is what mine sounds like. Anyone else getting this?

well its def not the ART pipes that make the hiss on their own. was talking with kevin today, he just replaced his Gemini with the CNT racing exhaust and said he noticed the hiss and his gemini never had it. Hes had HFC for a while now.

So the ART pipes/test pipes probably make it noticeable due to the increased flow but its something that needs to be fixed in the exhaust. Hopefully the motordyne exhaust will do that.