Cats Delete result in loss of power? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

catalan · 05-26-2012, 04:14 PM

I have a 2011 L99 with Stainless Works Retro Chambered Catback ... Recently I decided to replace the original cats with fabricated pipes in order to increase the true sound of the car ... I have made minor tunes and switched off AFM, and the engine light sensor ..

Having done that, I feel the car became lighter, but I feel that the power push when accelerating in a straight line is less than when I have my original cats on... I feel the car lost power without the original cats on ..

Any idea why is this happening? Have I lost pressure when I installed fabricated pipes? Do I need to buy a CAI to solve that? Or do I need a basic tune?

P.s.: The tuner wanted to increase the ignition timing and delete the factory's torque management but I was too concerned to do that as the car is still new and still didn't run over 10,000km. The car is not a daily use and I thought that such increase in ignition timing and deleting torque management would harm the engine in the long run.

Camper · 05-26-2012, 04:17 PM

i'd say the issue is in your tune.

catalan · 05-26-2012, 04:30 PM

Quote:

Originally Posted by Camper

i'd say the issue is in your tune.

It's not the tune .. I felt that before I did the minor tunes .. The car had a lot of power with the original cats on .. Now with the fabricated pipes installed instead, the car acceleration is less powerful when accelerating in a straight line ...

Ieatfordsforlunch · 05-26-2012, 05:01 PM

I'd say tune too.

SGOS252382 · 05-26-2012, 05:10 PM

You should have definitely increased HP by deleting the cats (15hp or so). I've seen dyno sheets from several cars making 15-18 hp from removing the factory cats.

Also, because you have an L99 A6, I would suggest reducing some torque managment. A good tune on an L99 A6 shows a real nice jump in Torque.

Kiowa88 · 05-26-2012, 05:11 PM

It's that whole loss of back pressure theory that no one seems to believe. I got the same feeling when i ran straight pipes. Just seemed to move the power band up higher in the RPMs. Its been proven with a dyno that you don't lose power. If you search "back pressure" you'll find the thread. It focuses more on loss of back pressure due to straight pipes, but it's the same concept. Hope that helps.

Ieatfordsforlunch · 05-26-2012, 05:33 PM

Quote:

Originally Posted by Kiowa88

It's that whole loss of back pressure theory that no one seems to believe. I got the same feeling when i ran straight pipes. Just seemed to move the power band up higher in the RPMs. Its been proven with a dyno that you don't lose power. If you search "back pressure" you'll find the thread. It focuses more on loss of back pressure due to straight pipes, but it's the same concept. Hope that helps.

Could be true too. I feel more on the side of the power band, but even so you still have the power there.

BubbaSS · 05-26-2012, 05:51 PM

It's definitely tune related...you lost some torque on the lower side of the band by removing the cats...A good dyno tune will fix that and even add a few more hp. Ultimately you have increased performance, just need to do it the right way

mikeSS · 05-27-2012, 12:39 PM

the car has a power band, people tend just to look at what you gain up top.people ALL the time report loss of low end power with straight pipe anything. specially without a tune.

idk why you dont tune, you already messed with the computer enough to the point where you are running a aftermarket tune.

SGOS252382 · 05-27-2012, 12:45 PM

Add an X pipe and you'll be good.

axis · 05-27-2012, 01:25 PM

Quote:

Originally Posted by SGOS252382

Add an X pipe and you'll be good.

Doesn't the Stainless works catback come with one?

Dtrimpi87 · 05-27-2012, 01:33 PM

Quote:

Originally Posted by axis

Doesn't the Stainless works catback come with one?

Yes it does

Sent from the rocket in my pocket, my all powerful DROID BIONIC.

SGOS252382 · 05-27-2012, 01:40 PM

Quote:

Originally Posted by Dtrimpi87

Yes it does

Sent from the rocket in my pocket, my all powerful DROID BIONIC.

If he's running a catback with X pipe I can't see him having issues.
Lots of guys are running long tubes, no cats, and catback exhaust making excellent power and torque.
Butt dyno is broken or back to the tune issue.

catalan · 05-27-2012, 02:52 PM

Quote:

Originally Posted by SGOS252382

If he's running a catback with X pipe I can't see him having issues.
Lots of guys are running long tubes, no cats, and catback exhaust making excellent power and torque.
Butt dyno is broken or back to the tune issue.

the SW Retro Chambered Catback comes with X pipe ..

Anyways, i had a basic tune and it seems that increasing ignition timing and disabling/deleting the factory's torque management solved the issue .. The car kicks/accelerates very well in cruising speed! Don't feel a loss of back pressure, a good basic tune solved it i guess ..

I guess switching off AFM and the Engine Light sensor with factory tune was what caused the power loss upon replacing the original cats with straight pipes ..

Synyster · 05-27-2012, 04:41 PM

It was the lack of a tune without cats, not really just cutting AFM

LBV · 05-27-2012, 06:02 PM

In what type of driving are you noticing the loss of power?

I can see you losing low end TQ in day-to-day driving with the car feeling more sluggish. That can happen.

Like someone's mentioned, you likely moved the power curve up higher in the rpm.

It's all about exhaust scavenging to keep the flow out of the engine at it's optimum.

Can a tune fix that? Not sure.

RBL · 05-27-2012, 06:54 PM

Quote:

Originally Posted by Kiowa88

It's that whole loss of back pressure theory that no one seems to believe. I got the same feeling when i ran straight pipes. Just seemed to move the power band up higher in the RPMs. Its been proven with a dyno that you don't lose power. If you search "back pressure" you'll find the thread. It focuses more on loss of back pressure due to straight pipes, but it's the same concept. Hope that helps.

I cant believe that people actually believe this crap. Engines do not like, need, or want back pressure. It's all a matter of the velocity of the gasses in the exhaust.

14pilot · 05-27-2012, 07:15 PM

Quote:

Originally Posted by RBL

I cant believe that people actually believe this crap. Engines do not like, need, or want back pressure. It's all a matter of the velocity of the gasses in the exhaust.

So tired of read the "backpressure" myth. Truely is pure crap...

05-26-2012, 04:14 PM	#1
catalan Drives: - Join Date: Nov 2010 Location: Bahrain Posts: 150	Cats Delete result in loss of power? I have a 2011 L99 with Stainless Works Retro Chambered Catback ... Recently I decided to replace the original cats with fabricated pipes in order to increase the true sound of the car ... I have made minor tunes and switched off AFM, and the engine light sensor .. Having done that, I feel the car became lighter, but I feel that the power push when accelerating in a straight line is less than when I have my original cats on... I feel the car lost power without the original cats on .. Any idea why is this happening? Have I lost pressure when I installed fabricated pipes? Do I need to buy a CAI to solve that? Or do I need a basic tune? P.s.: The tuner wanted to increase the ignition timing and delete the factory's torque management but I was too concerned to do that as the car is still new and still didn't run over 10,000km. The car is not a daily use and I thought that such increase in ignition timing and deleting torque management would harm the engine in the long run.

05-26-2012, 04:17 PM	#2
Camper Drives: 10' 2SS LS3 M6 Join Date: May 2012 Location: Phoenix,AZ Posts: 986	i'd say the issue is in your tune. __________________ 10'SS- 417ci\|ECS Novi 2200\|Alky Control\|10 Rib\|ATI Balancer\|Squash E85\|ID2000\|Fast 102\|FSP custom grind cam\|TSP LT's\|Vmax\|Pfadt\|BMR\|Farks\|Mantic 9000\|DSS Driveshaft & Axles\|JRE Billet Caps\|Eaton Tru-Trac\|LPW\|Rx\|Katech\|Barton\|Corbeau\|Braille\|TSW\|Weld \|NT05R\|-Mine 10'GT500- JLT 123mm\|Cobra Jet 65mm TB\|VMP Elbow\|VMP 2.5 pulley\|Dynatech LT's\|AFCO Heat Exchanger\|Cobra Jet drag springs\|MGW\|Dark Stars\|Mickey Thompson ET-Wifes https://www.youtube.com/user/CamperRacing Matt @FSP is the best vendor money can buy! http://www.floridaspeedandpower.com/2010-camaro-ss/

05-26-2012, 05:10 PM	#5
SGOS252382 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2008 Location: S.W. Florida Posts: 5,958	You should have definitely increased HP by deleting the cats (15hp or so). I've seen dyno sheets from several cars making 15-18 hp from removing the factory cats. Also, because you have an L99 A6, I would suggest reducing some torque managment. A good tune on an L99 A6 shows a real nice jump in Torque. __________________

05-26-2012, 05:11 PM	#6
Kiowa88 Out Front! Drives: OH-58D (R) Join Date: Jan 2011 Location: Savannah, GA Posts: 139 View My Garage	It's that whole loss of back pressure theory that no one seems to believe. I got the same feeling when i ran straight pipes. Just seemed to move the power band up higher in the RPMs. Its been proven with a dyno that you don't lose power. If you search "back pressure" you'll find the thread. It focuses more on loss of back pressure due to straight pipes, but it's the same concept. Hope that helps. __________________ B Troop, 3-17CAV - Out Front

05-26-2012, 05:51 PM	#8
BubbaSS WHAT RED LIGHT?! Drives: 2011 Black Camaro 2SS/RS M6 Join Date: Apr 2011 Location: Miami, Florida Posts: 300	It's definitely tune related...you lost some torque on the lower side of the band by removing the cats...A good dyno tune will fix that and even add a few more hp. Ultimately you have increased performance, just need to do it the right way __________________ 2011 2SS/RS M6 BLACK - VARARAM NO TUNE INTAKE, DOUG THORLEY LT'S, MAGNAFLOW HIFLOW'S, X-PIPE, 25" STAINLESS WORKS RETRO CHAMBERED MUFFLERS, CUSTOM 2.5" MANDREL BENT EXHAUST, RICHMOND 4.10 GEARS, CUSTOM CAM KIT & DYNO TUNED BY TORQ (WWW.GETTORQ.COM), 20% CERAMIC TINTS, EIBACH PROKIT SPRINGS 1" DROP, HYDROCARBON TAIL LIGHT AND FOG LIGHT BEZELS BY EMBLEMPROS, METRA DASH KIT, JVC KW-AV71BT, PHOENIX GOLD iAMP GM1, PASSPORT QI45 - MUSTANG DYNO RESULTS: 431 RWHP 390 RWTQ

05-26-2012, 05:01 PM	#4
Ieatfordsforlunch Drives: 2012 camaro 2ss Join Date: Apr 2012 Location: From So Cal lives at Fort Knox KY Posts: 312 View My Garage	I'd say tune too.

05-27-2012, 12:39 PM	#9
mikeSS Drives: 2013 E92 M3 Join Date: Nov 2009 Location: MI Posts: 7,294	the car has a power band, people tend just to look at what you gain up top.people ALL the time report loss of low end power with straight pipe anything. specially without a tune. idk why you dont tune, you already messed with the computer enough to the point where you are running a aftermarket tune.

05-27-2012, 12:45 PM	#10
SGOS252382 Drives: 2010 Camaro 2SS/RS Join Date: Mar 2008 Location: S.W. Florida Posts: 5,958	Add an X pipe and you'll be good. __________________

05-27-2012, 04:41 PM	#15
Synyster Drives: 2006 F150 Lariat Join Date: May 2010 Location: Florida Posts: 1,122	It was the lack of a tune without cats, not really just cutting AFM

05-27-2012, 06:02 PM	#16
LBV Drives: G8 GXP manual Join Date: Sep 2010 Location: Canada Posts: 131	In what type of driving are you noticing the loss of power? I can see you losing low end TQ in day-to-day driving with the car feeling more sluggish. That can happen. Like someone's mentioned, you likely moved the power curve up higher in the rpm. It's all about exhaust scavenging to keep the flow out of the engine at it's optimum. Can a tune fix that? Not sure. __________________ 2009 GXP, Manual with Sunroof Zeta platform, LS3,TR6060 tranny ... ya, it's a 4-dr Camaro! Borla cat-back, H&R springs, & Sprintbooster & I love it!