Berk HFCs on Factory Nismo Exhaust *RASP*

christian370z

Did you go to SpecialtyZ by chance? The last time I heard a Berk HFC/Nismo CBE combo, it sounded great and was still the traditional deep Nismo sound. I have to admit Berk HFCs and a stock cat-back exhaust is a bit raspy at times but it all depends on your preference.

There always could be a small leak somewhere,but other than that I am not sure what could cause that much rasp.

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-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob

QVu

Yea I went to specialtyZ, I just dont know how it could be so raspy!

QVu

Not knockin on Specialtyz by any means of course. They are awesome.

christian370z

Yeah, Seb mentioned you weren't a fan of the additional rasp when I was in there on Wednesday. Apart from the rasp, does it sound good under load?

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-320whp / 259wftlbs-
SP Rays -- RE-11s -- SpecialtyZ Tune -- Swift Springs -- Stillen 25R Oil Cooler -- Stillen G3 Intakes -- Berk HFCs -- F.I. 12" CBE -- Stillen Sway Bars -- Es14 Spring -- INGS+1 lip -- CF Spoiler -- GTR Start Button -- VLED Parking Lights -- PWJDM V2 shift knob

QVu

Hehe what a coincidence.

Yea i love the sound at all rpms, but i tune into the annoying rasp too much. just kills it for me.

chops

i agree...even though its 50 degrees outside (COLD for us californian's) i roll down the windows pretty often and listen to the exhaust rumble. it sounds so great except for that range between 3k-ish where the rasp is. its pretty nasty sounding when you're doing a high RPM downshift too

QVu

Yea I do love it once the engine is warm. I went to Seb at SpecialtyZ again yesterday and he said this is normal, and the rasp really varies between cars even though their setups may seem the same. I truly hope it does get quieter over time. The time from now until I scrape enough money to go FI. hehe.

tjlazer

That is not bad at all and hardly should be of a concern. Sounds great IMHO. Make sure the O2 sensor bungs are tight, could be a small rattle.

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2009 370Z Monterey Blue,Nismo Conversion,RE-11's, K&N Typhoon intakes,Blue Kickplates,Homelink,FI 18" CBE,ERZ HFCs,Hotchkis sways, Swift Spec-R, EVO-R Highwing, UPREV

QVu

Yea im sure ill get used to it. I love how its deeper now. i'll check the 02 sensor tonight. thanks for the comment!

BalanBro

Does is make that noise on decel too? I have an aftermarket exhaust and I get it too, but more noticeably when i let off the gas and coast.

I'm starting to think it may be eminating from the flex pipe (the walls might be really thin to allow it to bend). Does the OEM Nismo exhaust have flex joints up front too?

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2012 Mercedes C63 AMG P31 Sedan, ROW, aFe, Eurocharged Dyno Tune. 438WHP/415WTQ
2010 SOLD: 40th Anniversary 370z

chops

yes there are flex joints right basically right after the stock exhaust connects to the cat's. i have been under the car while it was on and there WAS a rattling noise coming from the flex joint area, but i fixed that (theres some heatshields a few inches down from the flex joints and i found some small pebbles in between the shields and the pipes).

im hoping to get under the car again today to see if i can bend any heatshields (as well as fix a CEL issue with some steel wool) which may be causing that rasp, but we shall see...going under the car while warm is pretty damn scary haha

Mont

I have been searching the forum for posts on this issue for a while. Addressing your issue first, the first video isn't that bad, but the second one would make me not want to drive the car at all. I am experiencing a rattle, not so much a raspy noise, and I've noticed it more on deaccel'. I believe I heard it a little on your first video.

Now on to my issue. I had the Berk HFC's, and the Injen cai's installed in Aug. I didn't notice the rattle immediately after the install, but it grew after I put a few miles on the parts. I figured it needed some break in time, and decided to take the car on a trip through a few states. Although I thouroughly enjoyed bonding with my new toy the noise had only grown worse by the end of the trip. If I was disgusted by the noise from the inside I can only imagine how it sounded to the group of onlookers who'd gather around my car outside of a hotel as I drove off. I'm sure it wasn't the symphonic orchestra. Anyways I have decided to remove the parts when I return, and go FI. If I have to deal with aggravating noises I'd rather have more power.

Hopefully you're able to solve your issues, and pass the word along to the others dealing with similar problems. Good luck.

QVu

Yea in speaking to Sebs from SpecialtyZ again, who did my install, he had said that the rattle/rasp was normal and its basically something ill have to live with. Its not that bad when the engine is warm, but it can be disgusting when cold as you heard in my second video. I am going to play around with the heat shields this weekend and see if there is rattling coming from there too. But, it looks like ill be living with this sound until i save enough for FI as well.

About the injen CAIs, did you experience any noticable gains with that part alone?

Mont

To be honest I was strapped for time, and a bit hasty. I had both parts installed on the same day, and didn't even bother getting a baseline. I arrived at the shop over an hour late for my appointment thanks to a late mail truck, and a two hour drive in traffic. After throwing in adequate cool down time I was lucky to get the job done at all. Good thing the mPM you the infoechanic was a big fan of the Nismo.

While perusing through the forum before purchasing my parts I think I noticed a post with the dyno numbers for my setup. I don't recall if they recorded numbers for each individual part, but if I come across it again I'll .

F1loco

Just don't waste your time deleting the rear can with test pipes or HFCs...your ears will bleed...I'm talking louder than most tracks will allow...took mine off and ended up with just stock CATs and rear muffler delete...which I had some more flow in the CATs for more burbles and pops on the overrun, but at least there is no rasp...