Well at least now I know that I am not alone with this. I am still looking for a fix, let me know if you find anything. Good luck.

 

Well, i was looking at 'rasp' on google, and there was mention of the E46 m3's well reknown rasp, and apparently, the only was to get 'rid' of it is to change the whole exhaust system to one which was designed to NOT GIVE a rasp. So, i am assuming then that this rasp is actually a complex acoustic wave issue caused by certain scientific factors, not a 'fault' per say. . . great. . . . .out with the calculators then. .

 

My brain hurts

 

The problem is now w/ test pipes, and the stock Y-pipe, there is alittle covering over part of the flex pipes on the Y-pipe. With TPs, you now have ALOT more vibration, and this is causing the covering to rattle against the flex pipe. You only really hear it as the RPMs begin to go down or when you decelerate. New Y-pipe, or get a custom fabricated pipe to go in place of the flex pipe sections on the Y-pipe. Solved.

 

You sure? :d

Most new Y-Pipes have flex pipes with them anyway, granted, they dont have that ghey heatshield the standard Y-Pipes do, but ive heard stories of ppl even with aftermarket Y-Pipes and they STILL make that noise with testpipes. . . .

Think i might start a poll. . . .

 

I have a crawford cats + jic ypipe + nismo exhaust combo and i'm getting hissing when i left off. No exhaust leaks from what i can see.

 

when i had my civic i took out my resonator completely and welded a pipe in to connect. and id get a rasp at idle and when shifting.

thats the reason i got a 350z cuz it has a great STOCK sound and it was MADE like that.

also the stock exhaust is supposed to be able to flow 500hp of pressure. although i might get a new y-pipe. but STOCK FTW!

 

The noise most people have w/ aftermarket is due to the fact that they use the gaskets provided w/ the new exhaust. OEM gaskets are literally 100x better. BUT even w/ the OEM, you sould always apply gasket sealent, i dont recal what it is called, but basically it drys up (looks like cement or clay) and then dries up to seal it very nice. The best part is that it is not like cement, and impossible to remove. If you want to swap for example the testpipes, you just unbolt it like normal, and the sealent you will notice is almost like a piece of thin paper. YOu need to use this stuff along w/ stock gaskets or aftermarket for sure if you got rid of the OEM.

 

So the gaskets provided are that bad? How about the gaskets provided with the NISMO exhaust?

 

The gaskets are fine.

 

If you dont have flex pipes, and you are hearing a hissing noise its a leak, that is most likely coming from the gaskets.

 

I am also getting this noise and it's getting worse. Debating between Borla and just a y-pipe now

 

*UPDATE*

Well, the crap just keeps getting DEEPER! A couple of days ago I ordered Injen SES exhaust in hope of fixing the SCREECHING that is going on at the Y-pipe since I put these damn test pipes on. Well, I am driving home from the driving range yesterday and a buddy was following me. He gives me a call and says I need to pull over because I have a problem. Smoke is coming out of my exhaust now. I figured that it was just the "normal" smoke from the lack of cats, but I am afraid it is something else. This is a little too much smoke for me to be comfortable with. Now I am worried that I have a piston seal gone bad, or worse... a head gasket gone bad!!! WTF?!?!?!?!?!?! I am starting to lose sleep over this! I also, a couple of days ago, reset the ECU by unplugging the battery. That worked just fine and the CEL went off just like it should. Last night as I was leaving my girlfriends house the damn CEL came back on. I am now begging for help from the Z Gods!

BTW I drive a 2004 6 speed with 32000 miles on it.

 

What color is the smoke? Smell? You know code you're throwing?

 

This smoke color is hard to pinpoint. Grey or light blue. Smell is normal exhaust smell. I have no idea what code I am throwing. I believe that this afternoon I am going to try to put my cats back on leave those on for about a week and see if I cant take it in to Nissan. Where can I check what the code is without going to Nissan?

 

You guys can eliminate rasp by adding resonators to the system. The resonated test pipes don't do a lot for the rasp because it is before the y-pipe. If you guys weld two 2.5" resonators on your aftermarket y-pipes, you will be fine, no rasp.

 

sounds like dirt and pebbles, mine too. more with headers? getting headers installed next month. i don't mind the noises my car makes. i chose to go that route. remember what they say, "when adding race parts, street civility is comprimised." no complaints.