No way? The rasp got louder with the FI exhaust?! He told me it would eliminate the rasp completely! He even said that he would give a money back guarantee if the rasp was still there! Now i really don't know what to do...I read for some the rasp went completely away with the FI exhaust though.

Do you have a video by chance?

The rattle on decel is what I mean. Around 2 grand. From 1 to 10. Its an 8. Sorry I get those 2 mixed up
Its so loud after the install its hard getting used to. So I read and asked questions why? They all say its from my res.Tps. No back pressure and its just air making that noise the motor creates. So my other question was, "is there anyone making a Tp that stops this Really anoying rattling hissing noise that wasn't there to began with? My 300,350,FC and Fd never did it. They all had catbacks w tps. Wth? Sorry im all heated up im just tired of throwing my money into this car and creating new situations that weren't there from the start. I feel embarrassed driving it sometimes. I guess hfc or stock cats will eliminate some rattle. Dam this motor. Lol

I haven't mastered posting vids on here yet. Maybe I can send it to you and you can post it for me.

The only other suggestion was one that I was planning to do. I was going to take my OEM H-pipe to a fab shop and ask them to follow the rough path and bends but with 2.5" pipes all the way and install (2) Vibrant resonators somewhere in there as well. Our VQ engines are not the only ones having this issue when freeing up the exhaust. I have read that the newer BMW M3 and other high compression engines have this rasp as well.

I am pretty sure that I would agree that it is the TP's that causes a lot of the raspiness. The choice is either resonated TP with stock muffler or aftermarket exhaust with stock cats...these combination's seem to be the common theme in people not getting that rasp sound in engined deceleration.

The resonators will only dampen the sound a bit though....I am sure that it will still be there...just a bit "softer".

Currently I am running GTM resonated TP's, joined to Sunline H-pipe, ending at the Amuse Nismo Extra Silent exhaust. It does have that rasp....quite a bit. Eventually I am planning to make some adjustments to the Sunline pipe and see how that goes. The flanges were crooked anyhow...so I have to cut it anyway.

Does anybody have any opinions on whether the nismo exhaust with the FI resonated HFC's still has the rasp sound? Or does anybody have this setup and and a sound clip? I have 2011 nismo with K&N typhoon, and I'm undecided whether to purchase the FI resonated HFC's. Need some advice guys

Birdmanx1 had HFC's with the stock Nismo exhaust I believe. Scroll through his journal, I think he has a sound clip in there.

http://www.the370z.com/members-370z-...o-journal.html

Thanks alot man, for the info

Now, I'm really interested in the Fast Intentions HFC's, but Im not sure which one should I get, the normal HFC's or the resonated HFC's? Need some help guys.

Regarding the raspy sound: the Nismo is Japanese...

True I agree, but now would you guys think the Fast Intentions Resonated HFC's would reduce the rasp? If so, how much would you guys think it will be reduced? Also, should I just go ahead and purchase the Fast Intentions Resonated HFC's or just the Normal Fast Intentions HFC's. Need some advice before I purchase them this week

I think you meant hfcs vs rtp?
Its really up to you. Your still gonna have rasp w both regardless. The hfc will eliminate mostly all but will restrict flow and power.Rtp will give you a bit more rasp(not much noticeable )and free up more power and flow. I personally like more power and flow. This car after awhile ALWAYS needs more power. You wont notice rasp until the higher revs anyway. Not everyone puts this dd to the pins every light to even notice. Thank god it doesnt sound like rice a roni.

Check this out

HFC's

Fast Intentions

Resonated HFC's

Fast Intentions

Any thoughts on which ones should i get????

I know this is a dead post, but I just installed my Berk's HFC's testerday.....To say the least, I am dissapointed. Seems like I gained a little bit of low end power......but the rasp is embarrassing. I have Stillen G3 intakes (dont think they would effect this), and the Stillen CBE. It sounded great before the new cats, but like all of us I wanted more power.......When the RAsp is not there, it sounds much more agressive, in a good way. When the RASP is there, all i hear is a coffee can civic, but unfortunately, its my Z.

If you can get larger resonators on your exhaust it will help a lot. I have the z1 hfc setup with a Fast Intentions exhaust. I started wi a 12" resonators. It was loud and sloppy (but actually sounded good -very mean). It was too much though and I went to an 18" resonator. Night and day difference. It is not as loud and has smoothed out quite a bit.

I have Berk HFC and stock Nismo exhaust. Rasp is gone but I have a rattle, not a rasp, at 2 k rpm on decel. But it's not loud and when I'm driving I can't hear it. If I'm in the garage with windows down I can hear it. It comes from the back of the h pipe. It's some weird resonance with the heat shield. Next oil change I'll have the tech poke around and see if they can bend it. Oh if you have an intake and HFC you really need a tune.

I have the FI resonated HFCs on stock nismo and no rasp at all.

One thought (sorry if it's been covered) but is it possible you have a leak? Most likely at the manifold/hfc joint.

I would HIGHLY recommend the Z1 gaskets. REALLY quality metal gasket that all but eliminates any chance of leak, and cheap.