High-Flow Cats Discussion - HFC

osbornsm · 04-11-2012, 04:55 PM

Hello all,

I am wondering why people buy HFC or Test pipes. When dealing with the smell of unburnt fuel, CEL, and emission testing... It seems about $600 for 5hp... correct me if i'm wrong, but it seems like $$ could be better spent.

...or is it just a matter of getting every last drop of HP from the car. I thought a Cat-Back exhaust pretty much got all the gains that could be had via exhaust.

VOTE IF YOU READ THIS

Thanks all,

LakeShow · 04-11-2012, 04:56 PM

The cats are most restrictive part of the whole exhaust system.

osbornsm · 04-11-2012, 04:58 PM

Quote:

Originally Posted by LakeShow

The cats are most restrictive part of the whole exhaust system.

But dollar-to-dyno... doesn't seem worth it??

SPOHN · 04-11-2012, 05:36 PM

I like TP's for many reason. I'm more of the hard core enthusiast first of all. But TP's for me are cheaper, lighter, more flowing, great sound (IMO), love the smell of raw fumes, and I don't have emissions.

ZCarMan · 04-11-2012, 05:38 PM

In addition to the benefit of opening up the air flow, the sound is also more aggressive sounding and for me that was what I wanted. I have no issues with the smell of fumes. Never had a problem passing emissions, since no CELs are on it. Here they won't sniff test it unless you show having thrown a CEL(s).

Crux · 04-13-2012, 01:08 PM

Quote:

Originally Posted by ZCarMan

In addition to the benefit of opening up the air flow, the sound is also more aggressive sounding and for me that was what I wanted. I have no issues with the smell of fumes. Never had a problem passing emissions, since no CELs are on it. Here they won't sniff test it unless you show having thrown a CEL(s).

Jon, do you have test pipes? Your exhaust sounds awesome.

370ZilverZ · 04-11-2012, 06:42 PM

Berk HFC's and ARK CBE's. No raw fuel smell and sounds good too.

370Z JT · 04-12-2012, 02:17 AM

I felt the most gains when I installed the ART pipes. Well worth it IMO.

MaDMaXX · 04-12-2012, 02:12 PM

Quote:

Originally Posted by 370Z JT

I felt the most gains when I installed the ART pipes. Well worth it IMO.

osbornsm · 04-13-2012, 11:09 AM

Oh come ON... 200 views and only 24 votes

Baer383 · 04-13-2012, 05:56 PM

Quote:

Originally Posted by osbornsm

Oh come ON... 200 views and only 24 votes

It also plays a big role if you are FI or NA

SPOHN · 04-13-2012, 07:12 PM

Quote:

Originally Posted by Baer383

It also plays a big role if you are FI or NA

Oh really. Hehe

jwick · 05-15-2014, 09:51 AM

I did all the standard bolt-on (intake, CBE, HFCs) mods prior to going FI. The HFCs were by far the best (most gains) of the bolt-on mods.

Nick M · 05-15-2014, 10:29 AM

When people post "but its only 5hp", you're missing the point.

Modifications are synergistic. They all work together. Sure JUST HFC's might yield 5whp (just guessing) but when you add other components, they all work together to make the most power.

Any one particular part might not be a great bang for the buck, but when you start adding them together, thats where you get the benefits.

I can guarantee that adding HFC's to an already existing free flowing 3" cat-back exhaust system is going to yield noticeably more power than doing "just HFCs".

Roddy1 · 05-15-2014, 11:24 AM

I'm pretty sure high flow cats have dyno'd much higher than just just 5whp whether it is 8whp or 15whp or somewhere in between, opening up the biggest restriction in the exhaust is going to produce nice gains under the powerband and improve driveability.

View Poll Results: The exhaust I am currently running...
OEM Cats + OEM Cat-Back	10	9.09%
OEM Cats + Other Cat-Back	24	21.82%
HFC + Other Cat-Back	57	51.82%
Test Pipes + Cat-Back	19	17.27%
Voters: 110. You may not vote on this poll

04-11-2012, 04:55 PM	#1 (permalink)
osbornsm A True Z Fanatic Join Date: Jun 2011 Location: WHAT Posts: 2,551 Drives: 2018 Camaro SS 1LE Rep Power: 424	High-Flow Cats Discussion - HFC Hello all, I am wondering why people buy HFC or Test pipes. When dealing with the smell of unburnt fuel, CEL, and emission testing... It seems about $600 for 5hp... correct me if i'm wrong, but it seems like $$ could be better spent. ...or is it just a matter of getting every last drop of HP from the car. I thought a Cat-Back exhaust pretty much got all the gains that could be had via exhaust. VOTE IF YOU READ THIS Thanks all, __________________ 2018 Camaro SS 1LE (455hp) - 2011 Nissan 370z (333hp) - 2004 VW R32 (240hp) - 2000 Civic Si (160hp) Last edited by osbornsm; 04-17-2012 at 10:13 AM.

04-11-2012, 04:56 PM	#2 (permalink)
LakeShow A True Z Fanatic Join Date: Dec 2010 Location: L.I., NY Posts: 5,307 Drives: Everything Rep Power: 26	The cats are most restrictive part of the whole exhaust system. batman_4, NoirG and Roddy1 like this. __________________ \|2013 Audi S4\|Ibis White/Black\|S-Tronic P+\| \|2013 370z\|PearlWhite/Persimmon\|Touring/Sport/Nav\|F.I. CBE 18" CF\| \|Sold\|2011 370z\|Gun Metallic\|Touring/Sport/Nav\|

04-11-2012, 05:36 PM	#4 (permalink)
SPOHN A True Z Fanatic Join Date: Feb 2010 Location: Covington, GA Age: 46 Posts: 14,844 Drives: Waiting on next Z Rep Power: 222	I like TP's for many reason. I'm more of the hard core enthusiast first of all. But TP's for me are cheaper, lighter, more flowing, great sound (IMO), love the smell of raw fumes, and I don't have emissions. gbrettin likes this. __________________

04-11-2012, 05:38 PM	#5 (permalink)
ZCarMan A True Z Fanatic Join Date: Jun 2009 Location: MD Posts: 4,488 Drives: 09 Z34, 13 F-150 Rep Power: 26	In addition to the benefit of opening up the air flow, the sound is also more aggressive sounding and for me that was what I wanted. I have no issues with the smell of fumes. Never had a problem passing emissions, since no CELs are on it. Here they won't sniff test it unless you show having thrown a CEL(s). __________________ Jon Swift \| SPC \| Stillen \| Motordyne \| AAM \| Cobb \| Hawk \| Volk Racing \| Bridgestone Green Demon Eyes

04-11-2012, 06:42 PM	#7 (permalink)
370ZilverZ A True Z Fanatic Join Date: Dec 2011 Location: DFW, TX Age: 67 Posts: 2,321 Drives: '11 BMW Z4 Rep Power: 19	Berk HFC's and ARK CBE's. No raw fuel smell and sounds good too. __________________ 370ZilverZ Journal BMW Z4

04-12-2012, 02:17 AM	#8 (permalink)
370Z JT A True Z Fanatic Join Date: Jan 2010 Location: United States Posts: 2,905 Drives: 370Z PW 7AT Rep Power: 379	I felt the most gains when I installed the ART pipes. Well worth it IMO. __________________ Click for My Journal Top Secret \| EVO-R \| Fujimura Auto \| Shine Auto \| Seibon \| MRWorks \| Swift \| SPC \| SSR \| UpRev \| Project Kics \| NST \| Titek \| Eibach \| Nismo \| Whiteline \| Quaife \| Invidia \| Fly1 \| CF Element \| Carbon Signal

04-13-2012, 11:09 AM	#10 (permalink)
osbornsm A True Z Fanatic Join Date: Jun 2011 Location: WHAT Posts: 2,551 Drives: 2018 Camaro SS 1LE Rep Power: 424	Oh come ON... 200 views and only 24 votes __________________ 2018 Camaro SS 1LE (455hp) - 2011 Nissan 370z (333hp) - 2004 VW R32 (240hp) - 2000 Civic Si (160hp)

05-15-2014, 09:51 AM	#13 (permalink)
jwick A True Z Fanatic Join Date: Dec 2010 Location: Houston Posts: 14,532 Drives: '10 G37 6MT Rep Power: 2465057	I did all the standard bolt-on (intake, CBE, HFCs) mods prior to going FI. The HFCs were by far the best (most gains) of the bolt-on mods. __________________ '10 G37T 6MT Graphite/Graphite - BP - G37T Build

05-15-2014, 10:29 AM	#14 (permalink)
Nick M Enthusiast Member Join Date: Nov 2013 Location: Poughkeepsie, NY Posts: 281 Drives: 2009 370z Rep Power: 12	When people post "but its only 5hp", you're missing the point. Modifications are synergistic. They all work together. Sure JUST HFC's might yield 5whp (just guessing) but when you add other components, they all work together to make the most power. Any one particular part might not be a great bang for the buck, but when you start adding them together, thats where you get the benefits. I can guarantee that adding HFC's to an already existing free flowing 3" cat-back exhaust system is going to yield noticeably more power than doing "just HFCs". __________________ \| 2015 Nismo headlights\| 275/305 \| Z1 spacers \| Eibach Pro-kit \|k&n typhoons \| AAM S-Line catback + FI test pipes \| Stillen splitter \|

05-15-2014, 11:24 AM	#15 (permalink)
Roddy1 Enthusiast Member Join Date: Jan 2014 Location: Canada/Cayman Islands Posts: 274 Drives: SRT Viper Rep Power: 12	I'm pretty sure high flow cats have dyno'd much higher than just just 5whp whether it is 8whp or 15whp or somewhere in between, opening up the biggest restriction in the exhaust is going to produce nice gains under the powerband and improve driveability. batman_4 and Chuck33079 like this. __________________ 2011 370Z, 6-Speed Manual, Sport Package. - K&N Drop ins \| Top Speed Axleback \| H&R Spacers SOLD 2009 G8 GT, 6.0L LSX V8, Rotofab Intake, ARH Long tubes, SOLO exhaust, VMS Tune - SOLD

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