What's been your experience with HFCs?
 

I only have two more power mods I'm considering for my G35. That would be HFCs and the TS ECU flash. I figured if I'm going to do HFCs, I'll need them before the flash in case TS does something to the tune to improve power with the HFCs. My car's current power mods (some questionable) are:

Revup airbox
OEM G-tube with resonator cut off
MD 5/16" spacer
HR y-pipe
05/06 sedan midpipe

Owners of HFCs, can post up the following:

1) HFC brand
2) Length of ownership
3) Reliability
4) Fitment, leaks, etc.
5) Volume change and funny noises (ie hissing, rattles)
6) Driveability (ie. does the car feel more powerful all around, is throttle response weakened in the lower rpms, etc.)
7) Seat of the pants gains, dyno gains

Thanks for the info.

Well...ive only had them in for a couple weeks so ill tell ya what i know so far...

1. Berk Technology hfc's
2. 2/3 weeks
3. heh so far reliable
4. perfect fitment...rust was a pain in the *** but other than that perfect
5. definately louder, sounds much better...more exotic i guess you could say...enhances the stock note well..they are brand new so there is some hissing when i let off the gas...a small amount of rasp but yet again they still have to break in...nowhere near as bad as TP's would be...
6. Definately feels like it pulls more all around...the thing i liked the most was just how much better the car ran...sound and power wise...just felt like it was breathing way better and just much smoother in general even at idle
7. no dyno info...but definately a noticable difference...before i bought them i had heard that putting them in got rid of alot of restriction and you definately get some whp out of em...im happy

1) HFC brand - Kinetix
2) Length of ownership - 2yrs+
3) Reliability - No issues, even passed CA SMOG
4) Fitment, leaks, etc. - OEM like, though no brackets used, just header to exhaust mounting
5) Volume change and funny noises (ie hissing, rattles) - metallic sound added to exhaust note, somewhat sport-bike like
6) Driveability (ie. does the car feel more powerful all around, is throttle response weakened in the lower rpms, etc.) - harder pulls, not sure if slight throttle response loss was lessened or amplified by prior header install
7) Seat of the pants gains, dyno gains - noticeable mid-range/high-end butt-dyno gains. only dynoed car for before/after TS reflash, no specific before/after HFC install dyno.

I also have the 350zHR-y & 05-06middy on my Wife's sedan and definitely want to do HFCs+Tune on her car too, it helps that Technosquare is in SoCal.

Just wondering, have you taken your car to the track? and are you using non-foulers for your o2 sensors?

no real track time, no anit-fowlers needed.

Thanks for the info. What did the TS ECU flash net you?

^super smooth power band, mid-range across the board and like 18 peak.

I have kinetix too. Love Love Love them. Oh btw did i say Love them yet. For real though they add both sound and power. I had my injen exhaust on which was louder then stock. Put these on and not only did it give my butt dyno a twitch it also gave my wee wee a hardon with how deep the sound became. No homo. Worth the money. Oh ive had mine over a year now.

As far as sound goes, I thought I wouldn't like the sound having listened to exhaust clips online, but after installing berk hfc I actually love the sound. Lower / deeper at idle, louder all around at half throttle but not overly loud, and at WOT above 4000 you get this exotic sounding metallic scream in harmony with the standard vq note.

Mods -> ztube, mrev2 and spacer, berk hfc, hr 350z ypipe, uprev tune

dyno after the tune was 255whp, I didn't get a stock dyno but it was the same dyno/shop used from this thread:

https://g35driver.com/forums/intake-...-bolt-ons.html

So given the stock run in that thread and perhaps a ~10-15 hp gain from the tune itself the cats probably make around 10whp.

I can't speak about HFC, but test pipes were definitely the best bang-for-buck along with a reflash.

~5 years after CrawfordZ HFC, these ART pipes are the best power mod I did to my car.
Trust me on this one, if you can, skip HFC and try ART pipes.

See above

I might consider this route next. I'm contemplating some exhaust options for when I have my Greddy TT kit installed. I'll report back here with some updates at that time

My stock and semi met berks all burned up. I went res test pipes. Dont know why they both failed. I run pretty rich most of the time.

~Dv8

I have the Berks at the moment, and they made a HUGE difference from Stock HFC. However, come spring I will definitely get the ART pipes a shot, they seem to be worth it and show some good power gains. Do the ART pipes throw a CEL?

Owners of HFCs, can post up the following:
1) HFC brand....BERK'S
2) Length of ownership....2 Months.
3) Reliability....Perfect!
4) Fitment, leaks, etc....Same as OE
5) Volume change and funny noises (ie hissing, rattles)....Zero noises/rattles, the sound of my HKS exhaust with the BERK'S is way deeper.
6) Driveability (ie. does the car feel more powerful all around, is throttle response weakened in the lower rpms, etc.)....Feel extra HP through out RPM range.
7) Seat of the pants gains, dyno gains....As advertised 8 to 10 HP gain.
* I suggest to anyone installing HFCs that you buy new OE gaskets to keep from having noises, not a fan of the gaskets that come with the HFCs.

Gary