Exhaust Leak or just a sound I have to live with?
 

I just installed a set of Berk non resonated test pipes along with my F.I. CBE that Ive had. Under Load Im getting a raspy noise from what sounds like under the car. On deaccelration, it makes a sucking sound...almost like an open wastegate. It doesnt sound like a typical exhaust leak sound so thats why im asking...is this common with tp's? Or do i have a leak?

almost like a hiss??

yes, but not from the rear.

You can check everything over again and make sure there aren't any leaks. Otherwise it's resonance from lack of restriction. A lot of exhausts do that, especially when you had test pipes or high flow cats to the mix.

Normal.

i currently have stillen hfc and FI exhasut and i get the hiss on decel and a hiss on high load accel. i am going to swtich my HFC to FI resonated HFC to try fix it a bit. becaus eon accel the hiss is extremely annoying. and i got my mechanic to look it over and there are no leaks

It's not going to fix it. I had resonated cat pipes and resonated test pipes. You're better off using exhaust wrap, that will minimize it.

Damn that sucks! I mainly work on Z32's and they dont have that problem :/
The sound really is annoying too, do FI's LTH's create that sound also?

Wrap just the test pipes?

Test pipes will definitely rasp a lot like you mentioned. Header wrap around the TP is a good inexpensive solution. Next best thing is look for something resonated if you are still unhappy with it. Regarding headers, they do have a much cleaner sound. My PPE's rasp but with a HFC, it's very minimal now. I haven't really heard any with the F.I. LTH's. Either way, it's an expensive upgrade from TP's to gain maybe 5whp.

What causes the hiss on decel? I only hear it if I'm sitting still and revving it and let off quick-not on the open road. So it really doesn't bother me - just curious. I've got FI resonated CBE and 18" resonated HFCs.

I don't get hissing on decel with my LTH's. Not sure about the F.I. headers. I only get a small hint of rasp, but its masked by scavenging. It might originate from the factory header design, idk, I'm only guessing from my limited experience.

does it sound like this?

^ Yes it does, just reving, on accelaration and decel

Very normal, unfortunately. You could exhaust wrap the test pipes and x-pipe to break some of the resonance. It does work, I've done it on two different exhaust set-ups.