Hisss
 

I think we should all embrace the HIss! It's unique to the Z and sounds badass!!

Personaly I hate the hiss.. I'm 99% sure it comes from the xpipe. I've sat under the car while someone revved it and most of the rasp/hiss comes directly from the xpipe you can clearly hear it.. I'd like to switch exhausts and test thigs out but that becomes expensive and I have no guarantees that it will be any different.

I haven't noticed any 'hiss'

Do you have HFCs or test pipes? Or are you running stock cats.

Stock cats, maybe thats why. Sorry been up all night

You are 99% sure and 100% correct. :tup:

The hiss DOES come from the X-pipe. Even my FI 18" CBE with STOCK cats has a little hiss. HFCs or test pipes only amplify the effect because they allow for higher airflow into the X pipe. The only exhausts that DON'T hiss are ones without a crossover pipe.

Toohip and ZCarMan both run the AAM Competition CBE (version 1) with HFCs and there is ZERO hiss.

What about exhausts with an H pipe like the HKS

Ok guys under much research and testing it is from the test pipes and possibly HFC. I bought 2 sets of test pipes, the FI resonated ones and Berk test pipes. They both created the hissing sound. The FI resonated ones a little less but it was still evident. I went back to stock cats and the beautiful exhaust sound was worth the sacrifice in power. With that being said I'm selling 2 sets of test pipes, any interest? lol :D

The problem is the X pipe..

No it is not...if anyone on this forum has experience with this, it is I.

I have many posts regarding this and all the different setups I went thru to somewhat resolve it.

The resonance (sound) definitly pops right before/at the X-H-Y pipes, but it is 100% started and caused because of frequency that begins with the addition of the test/HFC.

The closest thing to removing this sound is either adding resonators right before that joint (a la Invidia CBE, which still doesnt kill it completely, but greatly reduces it) or going back to stock cats.

I am going back to stock cats, the loss in power is worth having a cleaner sound + the upkeep in stains building up against the rear bumper. But then again, I'll be happy I'm putting them back on because that means my supercharger has arrived ;)

Daishi, it's not the X-pipe. Before I got my Ark exhaust I had the Berk TPs alone with a stock exhuast and STILL had the hissing sound. Like DannyGT said, its the resonance.

according to m4a1 if you have an exhaust without a crossover you dont get the hissing.. Its hard to pinpoint the sound exactly. On my car it sounds like it comes directly from the xpipe.

Yes the sound does come from the X-pipe but the CAUSE of the sound is the testpipes and HFCs.

Ok but if you can get an exhaust system that either has an xpipe design that doesnt cause any issues or something without an x pipe you can be happy while producing more gains.

the louder the hiss the more power your making!!! HISS FTW!!! :)