Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

cut out vs catback gains.

Thread Tools
 
Search this Thread
 
Old Sep 12, 2009 | 01:44 AM
  #1  
mastercoryd's Avatar
Thread Starter
Launching!
iTrader: (3)
 
Joined: Sep 2008
Posts: 272
Likes: 0
From: Johnston
Default cut out vs catback gains.

hey guys i have a question, right now i have true duals custom made and wanted to switch to a y pipe / lm2 catback, and doing so i wanted to install a single cut out in the y pipe 3". My question is how much horsepower will a cutout gain you over a slp lm2 or lm1 catback with just long tube headers and a lid. no head and cam. I dont care if its not much cause i do like how i can have the car fairly loud and then have it raise hell when i open it, so my question waas just how much hp would the cutout gain me just out of curiosity, thanks alot
Reply
Old Sep 12, 2009 | 01:45 AM
  #2  
lemons12's Avatar
TECH Senior Member
iTrader: (71)
 
Joined: Jul 2007
Posts: 11,088
Likes: 2
From: Winchester, TN
Default

10rwhp I would guess max..

Why would you go from TDs to a Ypipe?
Reply
Old Sep 12, 2009 | 02:32 AM
  #3  
camz28arro's Avatar
TECH Enthusiast
iTrader: (12)
 
Joined: Nov 2008
Posts: 590
Likes: 0
From: Long Island, NY
Default

I really would like to know the answer to this as well since the LM2 I just put on my car only has a 2-3/8 inner diameter. Also I was reading posts from 2002-2003 where the big thing was to get 4 inch piping but I don't think the 3 inch exhaust is choking the engine of anymore than 5hp at up to 400whp.

I'd say 5-10hp gain with a cutout over the LM2 and 0-5hp gain for LM1 but would really like to see the actual results.
Reply
Old Sep 12, 2009 | 03:36 AM
  #4  
mastercoryd's Avatar
Thread Starter
Launching!
iTrader: (3)
 
Joined: Sep 2008
Posts: 272
Likes: 0
From: Johnston
Default

Originally Posted by lemons12
10rwhp I would guess max..

Why would you go from TDs to a Ypipe?

the true duals hang to low and im about to lower my car and need it to tuck up, plus no one around me does mandrel bends so i figured i'd be better off with a single cut out for my hp purposes and for a clean daily driving setup have the lm2 catback
Reply
Old Sep 12, 2009 | 07:27 AM
  #5  
2002SS#1811's Avatar
Launching!
 
Joined: Mar 2004
Posts: 266
Likes: 0
From: SUGAR GROVE TOWNSHIP ILLINOIS
Default

Only lost about 5hp going from true duals to my current set-up. Listed in Sig. Get the cat back of your choice and a cut out and be done with it. Best of both worlds in my opinion.
Reply
Old Sep 12, 2009 | 07:36 AM
  #6  
ta-stanger's Avatar
TECH Regular
iTrader: (6)
 
Joined: Jul 2009
Posts: 495
Likes: 1
From: Lake Of the Ozarks, MO.
Default

I totally agree with the about statement. My magna flows are nice and quiet when I want to be. Then I just tap the switch and the beast awakes:>)!
Reply
Old Sep 12, 2009 | 10:15 AM
  #7  
mastercoryd's Avatar
Thread Starter
Launching!
iTrader: (3)
 
Joined: Sep 2008
Posts: 272
Likes: 0
From: Johnston
Default

Originally Posted by 2002SS#1811
Only lost about 5hp going from true duals to my current set-up. Listed in Sig. Get the cat back of your choice and a cut out and be done with it. Best of both worlds in my opinion.
only lost 5 hp with ur cutout open or closed compared to the TD setup, and did u have 3" true duals or no
Reply
Old Sep 12, 2009 | 12:17 PM
  #8  
2002SS#1811's Avatar
Launching!
 
Joined: Mar 2004
Posts: 266
Likes: 0
From: SUGAR GROVE TOWNSHIP ILLINOIS
Default

Originally Posted by mastercoryd
only lost 5 hp with ur cutout open or closed compared to the TD setup, and did u have 3" true duals or no
Open. Not much more running through the muffler No more raw fuel and overdone exhaust smell. Way to loud for the street also. 3 inch pipe by the way. Seat of the pants you would never know, only on the dyno could it be seen. Good luck
Reply
LS1 Tech Stories

The Best V8 Stories One Small Block at Time

story-0

Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

 Verdad Gallardo
story-1

6 Common C5 Corvette Failures and What's Involved In Repairing Them

 Pouria Savadkouei
story-2

Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

 Verdad Gallardo
story-3

Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

 Pouria Savadkouei
story-4

Top 10 Most Powerful Chevy Trucks Ever Made!

 
story-5

Hennessey's New Supercharged Silverado ZR2 Has 700 HP

 Verdad Gallardo
story-6

Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

 Verdad Gallardo
story-7

Awesome K5 Blazer Restomod Comes With C7 Corvette Power

 Verdad Gallardo
story-8

10 Camaros You Should Never Buy

 
story-9

10 LS Engine Myths That Refuse to Die

 Verdad Gallardo
Old Sep 12, 2009 | 02:12 PM
  #9  
Detoxx03's Avatar
10 Second Club
iTrader: (14)
 
Joined: Jan 2007
Posts: 7,336
Likes: 74
From: Woodward Avenue
Default

I gained 6wrhp/6rwtq from a cutout
Reply
Old Sep 12, 2009 | 03:47 PM
  #10  
camz28arro's Avatar
TECH Enthusiast
iTrader: (12)
 
Joined: Nov 2008
Posts: 590
Likes: 0
From: Long Island, NY
Default

Detoxx, I was watching your videos on youtube. Was the 6hp/6tq gain with the cutout open over the LM2 or the Borla Xr1 and do you know the inner diameter of the XR1 or if it gained hp on the switch. Thanks.
Reply
Old Sep 12, 2009 | 04:07 PM
  #11  
Detoxx03's Avatar
10 Second Club
iTrader: (14)
 
Joined: Jan 2007
Posts: 7,336
Likes: 74
From: Woodward Avenue
Default

Originally Posted by camz28arro
Detoxx, I was watching your videos on youtube. Was the 6hp/6tq gain with the cutout open over the LM2 or the Borla Xr1 and do you know the inner diameter of the XR1 or if it gained hp on the switch. Thanks.
It was open over the xr1. I don't know the inner diameter. I would go measure but I sold it long ago.
Reply
Old Sep 13, 2009 | 11:13 PM
  #12  
kkslds's Avatar
12 Second Club
iTrader: (59)
 
Joined: Mar 2007
Posts: 916
Likes: 1
From: Coffeyville, Ks
Default

i think i gained like 3rwhp with it open over corsa. Not for sure but I know it wasn't significant
Reply
Old Sep 20, 2009 | 11:03 AM
  #13  
camaro_ss_97's Avatar
TECH Apprentice
iTrader: (28)
 
Joined: Feb 2006
Posts: 349
Likes: 0
From: winchester, tn
Default

Originally Posted by mastercoryd
hey guys i have a question, right now i have true duals custom made and wanted to switch to a y pipe / lm2 catback, and doing so i wanted to install a single cut out in the y pipe 3". My question is how much horsepower will a cutout gain you over a slp lm2 or lm1 catback with just long tube headers and a lid. no head and cam. I dont care if its not much cause i do like how i can have the car fairly loud and then have it raise hell when i open it, so my question waas just how much hp would the cutout gain me just out of curiosity, thanks alot
well i have a 3in cutout and i gained more hp with mine closed rather than open just depends on your setup.
Reply
Old Sep 20, 2009 | 06:01 PM
  #14  
RedRocketZ28's Avatar
9 Second Club
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (19)
 
Joined: Jan 2005
Posts: 2,106
Likes: 4
From: Madrid, IA
Default

I don't gain a damn thing with mine open. Just makes a ton of noise. Shows how well the SLP dual/dual flows.
Reply




All times are GMT -5. The time now is 09:34 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE