Chops, I just listened to this clip and my nismo USED to make the same noise after I installed res tp from GTM. At first I thought it was coming from the tps but wasn't. When it was up on the lift we heard the noise coming from the h pipe. Like something was inside there. (Like a babies rattle) Just right around 3gish hold the gas pedal. The noise is steady even on deceleration around the same rpm. We all couldnt figure out why.Maybe because it has no back pressure and NISMO h pipe is only 2" - 2 1/8" But I came up with a cure. We removed the h pipe configuration and my guy build a 2.5 X pipe CB. The noise went away completely. Freed up power and sounds throaty. Im thinking you guys both have the factory Nismo cb with your tps and that's where your noise is coming from. Hope this info helps.

interesting...any pics of said X-pipe? i wish there was a nismo compatible X-pipe. id rather not get rid of the entire nismo exhaust

You dont have to. Heres 2 1/2 piping w X pipe. Replacing Oem 2'' H pipe. Stiil keeping the Nismo muffler and resonators. Sorry for the delay. I mainly got this done because of the lack sound,restriction and budget. Also because of the rattling noise @ 3 grand Rpm. That was really annoying. Paid less then half of a full CB and satisfyed for now.:tup:
http://i55.photobucket.com/albums/g1...s/IMG_1742.jpg
http://i55.photobucket.com/albums/g1...s/IMG_1744.jpg
http://i55.photobucket.com/albums/g1...s/IMG_1740.jpg


Factory Nismo H pipe
http://i55.photobucket.com/albums/g1...s/IMG_1745.jpg

Nismo H pipe flange 2"
http://i55.photobucket.com/albums/g1...s/IMG_1748.jpg

Nismo Flex pipe flange 2 1/8 "
http://i55.photobucket.com/albums/g1...s/IMG_1749.jpg

Can you please post sound clips of your setup with said X-pipe?

Thanks for the info, I'm planning on doing this as well... I wish someone would manufacture the X-Pipe other than Amuse (which costs $1600), I'll ask a shop to fab it for me.

antfd3s
 

Might the fellow who constructed your Nismo's X-pipe offer these for sale to interested Nismo owners?

I've sent an email to Fast Intentions inquiring about having them fab up an x-pipe for me to hopefully resolve that damn rasp/rattle. I wanna keep the Nismo exhaust but don't wanna pay $1700 for the Amuse pipe. We'll see what they say...

Look into the exhaust section. I posted a thread in regards to this and some of us are waiting to see if FI can do this for us for a reasonable cost.

http://www.the370z.com/intake-exhaus...ent-nismo.html

i talked to Tony and he'd be happy to custom build one for me. it'd be about a quarter of the cost of the amuse pipe, but you have to go to him. which isnt tough considering you're already in ventura county. i was planning to make a trip down sometime in the coming months and he was on board with it (but its a 700 mile round trip for me, gas is a bit**). give him a call...they're in northridge, which is an hour from you!

Yea I'll definitely give him a call. I'm actually like 15 mins from him so that would be perfect. I'll definitely keep you guys in the loop.

lucky you. i was hoping to be the first, but you can definitely go ahead!:tiphat:

I spoke to Tony and he said he would do it, but was pushing his TDX instead for like 500 more than it would cost to fab a custon x-pipe. I really am on the fence with doing just the x-pipe or changing the exhaust out completely. He said he couldn't guarantee the rasp would go away after the x-pipe was in because he hasn't done it to the nismos yet... What do you guys think?

thats totally upto you. for me i would definitely pony up the cash. hell i think i was quoted 500 for it to be done, and fuel costs would have been 150 for me to get there and back. i forgot to say..reason i would do it is because where i live, you are harassed for everything on your car. especially with the huge wing on the back of our hatch. i want to keep my exhaust looking as stock as possible! im also lowered, so those TDX cans would scrape everywhere i go!

keep in mind, the H-pipe is about a 2" pipe, then after the H-pipe is a 2.25" pipe to the resonators, and after the resonators it widens to 2.5" to the muffler. from having my car on the lift by a fellow Z enthusiast yesterday, he said this would create some nice backpressure, i'm likely going to have sonic motorsports fab me up an X-pipe from mandrel bends now. plan is as follows:

2.5" pipe from cat-back to X-pipe opening, then other end of X-pipe will be a 2.25" pipe to the flange of the resonator. this keeps all the stock widths, yet widens the area where there is the most restriction in our H-pipe. i'll post videos/pics whenever i have this done :tiphat:

:tup:
Thats a great plan you have!
I think i may wait a bit until I see more videos about people that have done this, to ensure that the rasp will go away entirely with the x-pipe alone. I really wanna keep the nismo to keep with the nismo theme on the car, but the rasp drives me crazy sometimes! Time to save a bit more cash money! Good luck with that fab work! I definitely wanna hear about it once its done! :tiphat:

Heres my story..
Guys, I don't think there's no way around the raspy sound. Even when I intalled a custom xpipe the rattle was gone. But the exhaust note wasn't the same. I expected it to be louder and have more of a grawl to it .. Now the problem was with exhaust note. The muffler gave me a raspy note. Like the muffler was getting to much air flow. It couldn't handle the power. Causing the sound to be a lil ricey. My exhaust guy that made the x pipe suggested removing the resonator section then going with 2 1/2 flaged resonators (either 12 or 14 ") and still use the Nismo muffler. SINCE I to didn't want to take the look away from my car. This is when my back was against the wall and choose to get a Catback from FI.
Now just a little info on this situation. THE RASP GOT LOUDER! lol the muffer tips don't stick out enough passed our bumper either. Also the xpipe section is 3 pieces! Why not make it 1? (So it can all fit in 1 box to ship was my guess)
The only thing I like is the sound while accelerating. Not happy w spending mad money and waiting 3 months to get it either. Back to the baby rattle/rasp. Its so loud I wanna take everything off and go back to stock and regroup my thoughts.