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Old 03-28-2010, 11:24 PM   #16 (permalink)
ZForce
A True Z Fanatic
 
Join Date: Jul 2009
Location: Roseville, CA
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Drives: 09 370Z Tour + Sport
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Quote:
Originally Posted by Nitex View Post
My thoughts in the end are somewhat of a mixed bag. I do love the sound, yet at times the loud hiss/rattle on decel truely annoys me. On the performance side of things my but dyno wants to tell me im that much faster. However i realize i need a tune and some dyno results to get an accurate result. I plan on getting tuned next weekend, and i will post up the charts soon. Here is my video with start up and a drive around town.
Quote:
Originally Posted by ZForce View Post
Nice write up and video, the Z now sounds angry! The hiss I have come to believe is the Berk HFC. Yeh it's annoying. Good bracket mod on the tube bracket. Keep an eye on the A/C hose as someone already mentioned that it cuased issues from rubbing.

In for dyno results.

I stand to correct myself, after some searching Tony from Fast Intentions sums up the hiss sound the best.

The link to the thread: Question about the hiss/rattle after installing HFC's

Quote:
Originally Posted by F.I. Inc. View Post
This is a common sound that has been associated dating back to the 2003 VQDE 350Z!

I have heard it more so than not. In my personal opinion it has nothing to do with the flex joints. None of our systems have ever had flex joints. There have been many speculative conclusions and my personal assessment is that it is the exhaust pulsating through the thinner wall aftermarket cats and exhaust systems. The more back pressure you relieve the louder it gets. Ex. we notice it to be more prominent with resonated test pipes than high flow cats. We hear it very little with stock cats and our cat back.

To chalk it up, it has more to do with the way the engines in these specific cars are constructed and the less to do with the type of exhaust system you put on it. Yes, thicker wall tubing will help it dissipate because less of the harmonics will make its way through so naturally you will hear less.

Lastly, out of all the production exhaust systems we manufacture this engine- VQDE, VQHR are the only cars we have ever heard it in!

I hope that this may help somewhat,

Tony
The entire thread is here: Question about the hiss/rattle after installing HFC's
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