HP Gains From Getting Rid of Cats on N/A Motor? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

47AJV8 · 06-21-2013, 06:09 PM

Been awhile since I posted on here last, but title pretty much says it all. I live somewhere where there are effectively no emissions laws and was wondering what HP gains can reasonably be expected with removing my cats on a car that already has intake and exhaust. (ECU tuning is out of the question for now) Thanks!

62nalide · 06-21-2013, 06:23 PM

If you won't be tuning the car do not remove them.

fourmz · 06-21-2013, 06:33 PM

if you pull them I dont think you will see any gains, also, if you pull them and dont tune the ecu to delete the rear o2 sensors your check engine light will light up.

Birm · 06-21-2013, 06:34 PM

Swap them for Hi-Flows 10-20whp'ish... and if you decide to go with nocats at all, yea youll gain a little, it will be bit more raspy and you will probably smell fuel out the backside...You will need a tune to get rid of the CEL though.

dekan513 · 06-21-2013, 07:11 PM

as brim said. there is a gain from stock cats to no cats or hfc. and a good gain at that

VADER SS L99 · 06-21-2013, 08:54 PM

If tuning is out of the question then you will need the Solo high flow cats. Those do give a good gain and don't throw a CEL or require a tune. I think I read that there is a way to use the JBA high flow cats to where you don't have to tune and wont get a CEL but someone else will have to chime in on that one as I don't know for sure.

47AJV8 · 06-22-2013, 12:08 AM

So would about 20 hp be expected as a reasonable gain? With a few little things to deal with of course, thanks for the tips guys.

Mr_Draco · 06-22-2013, 09:26 AM

Quote:

Originally Posted by nbrigdan

So would about 20 hp be expected as a reasonable gain? With a few little things to deal with of course, thanks for the tips guys.

20 is way high. At most you'll get 10 hp. The factory cats are restrictive but not that restrictive. As already stated, unless you get a tune, don't bother doing it.

47AJV8 · 06-22-2013, 11:30 AM

Oh alright, probably won't bother unless I go for tune, thanks.

Birm · 06-22-2013, 03:31 PM

Quote:

Originally Posted by Mr_Draco

20 is way high. At most you'll get 10 hp. The factory cats are restrictive but not that restrictive. As already stated, unless you get a tune, don't bother doing it.

I respectfully disagree. 20 is attainable, 10-15 is avg.

VADER SS L99 · 06-22-2013, 05:18 PM

Quote:

Originally Posted by Birm

I respectfully disagree. 20 is attainable, 10-15 is avg.

I agree as well and if you do the Solo high flow cats you wont need a tune. No cats would be out of the question with out a tune.

dekan513 · 06-22-2013, 05:38 PM

Quote:

Originally Posted by Birm

I respectfully disagree. 20 is attainable, 10-15 is avg.

1000% 10 is very low. those cats from factory suck for hp.

Mr_Draco · 06-22-2013, 05:49 PM

Well then lets just agree to disagree but I've seen a car dynoed, get hi-flos and a cat back installed, then redynoed and gain just a little over 10 hp with no tune.

Birm · 06-22-2013, 05:59 PM

Quote:

Originally Posted by Mr_Draco

Well then lets just agree to disagree but I've seen a car dynoed, get hi-flos and a cat back installed, then redynoed and gain just a little over 10 hp with no tune.

First, anytime there is a change you should allow for a re-learn period......Second, every dyno is different as is every car and the conditions in which they are dyno'd. And third, I have seen 3 cars personally in my club (TBC) who have put on HFC's who have made over 15whp. 10 is on the lowside. But as you said...agree to disagree.

06-21-2013, 06:09 PM	#1
47AJV8 Drives: A White Car Join Date: Dec 2012 Location: Canada Posts: 342	HP Gains From Getting Rid of Cats on N/A Motor? Been awhile since I posted on here last, but title pretty much says it all. I live somewhere where there are effectively no emissions laws and was wondering what HP gains can reasonably be expected with removing my cats on a car that already has intake and exhaust. (ECU tuning is out of the question for now) Thanks! __________________ "From ABS shudder that came on surprisingly early in the lousy brake pedal's travel to a looser rear end than Kim Kardashian"

06-21-2013, 06:23 PM	#2
62nalide Drives: 2013 SS Join Date: May 2013 Location: DFW Posts: 4,102	If you won't be tuning the car do not remove them. __________________ https://frankensteined.net/ Martin@Frankensteined.net

06-21-2013, 06:33 PM	#3
fourmz Fourmz Drives: 2010 2SS/RS 1968 Firebird 1994 Z28 Join Date: Sep 2009 Location: Soldotna,Alaska Posts: 382	if you pull them I dont think you will see any gains, also, if you pull them and dont tune the ecu to delete the rear o2 sensors your check engine light will light up. __________________ Black-in-Black/Blue out 2010 2SS/RS LS-3 -Magnacharger TVS2300,OD cog belt drive, 3.4" pulley, Janetty smooth idle blower cam,ID-850 injectors,ZL1 fuel pump,MSD boost a pump, ADM FPCM Janetty custom tune,Doug Thorley long tube headers, Corsa catback,C.A.I. Intake, Roto-Fab Big Gulp Scoop, Monster LT1/SC Clutch assembly,Eibach pro kit plus, BMR cradle/diff bushings, Barton Shifter,JRE 3.91 Eaton Tru-Trac rear diff,Barton Short Throw SHifter, Boss 339 20" wheels,Painted heritage grille, Sparks Restoration Inverted blue/black SS emblems, Seibon BB carbon fiber hood, ZL1 front bumper conversion.

06-21-2013, 07:11 PM	#5
dekan513 chevy pride Drives: 2ss/rs Join Date: Feb 2012 Location: pikeville ky Posts: 2,141 View My Garage	as brim said. there is a gain from stock cats to no cats or hfc. and a good gain at that __________________ check out ky speeds fb page https://www.facebook.com/kyspeed

06-21-2013, 08:54 PM	#6
VADER SS L99 Drives: 2013 A6 GT 5.0 Join Date: Nov 2009 Location: Edmond, OK Posts: 2,909	If tuning is out of the question then you will need the Solo high flow cats. Those do give a good gain and don't throw a CEL or require a tune. I think I read that there is a way to use the JBA high flow cats to where you don't have to tune and wont get a CEL but someone else will have to chime in on that one as I don't know for sure. __________________ BLK/BLK 1SS/RS Ordered 11-01-2009 Took delivery 12-22-2009. Heads/cam/converter/bolt ons. SOLD Feb 2015 to fund 6th gen LT1 SS with 8L90E.

06-21-2013, 06:34 PM	#4
Birm Drives: Florida Speed & Power Join Date: Jan 2011 Location: Pinellas Park, FL Posts: 3,185	Swap them for Hi-Flows 10-20whp'ish... and if you decide to go with nocats at all, yea youll gain a little, it will be bit more raspy and you will probably smell fuel out the backside...You will need a tune to get rid of the CEL though.

06-22-2013, 12:08 AM	#7
47AJV8 Drives: A White Car Join Date: Dec 2012 Location: Canada Posts: 342	So would about 20 hp be expected as a reasonable gain? With a few little things to deal with of course, thanks for the tips guys. __________________ "From ABS shudder that came on surprisingly early in the lousy brake pedal's travel to a looser rear end than Kim Kardashian"

06-22-2013, 11:30 AM	#9
47AJV8 Drives: A White Car Join Date: Dec 2012 Location: Canada Posts: 342	Oh alright, probably won't bother unless I go for tune, thanks. __________________ "From ABS shudder that came on surprisingly early in the lousy brake pedal's travel to a looser rear end than Kim Kardashian"

06-22-2013, 05:49 PM	#13
Mr_Draco Drives: 2SS/RS Join Date: Sep 2008 Location: Western North Carolina Posts: 7,359	Well then lets just agree to disagree but I've seen a car dynoed, get hi-flos and a cat back installed, then redynoed and gain just a little over 10 hp with no tune.