How much HP 2.5 exhaust? - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

black79ta · 08-20-2013, 03:13 PM

I have 1 7/8 kooks, 3×3 cats. Cut off the 2.5 " end of flowmaster AT welded on 3 inch end. 3 inches all the way back. Love it.

thahemp · 08-20-2013, 06:58 PM

Quote:

Originally Posted by black79ta

I have 1 7/8 kooks, 3×3 cats. Cut off the 2.5 " end of flowmaster AT welded on 3 inch end. 3 inches all the way back. Love it.

That's what I'm gonna do one of these days. I bought the neck-down version of the JBA 3" long before I got the headers. Simple problem with a simple remedy!

litle88 · 08-20-2013, 08:04 PM

I slapped a Flowmaster 3" catback and center mount exhaust with the kooks and I live it!

Craig B · 10-29-2013, 08:47 PM

Needed to update this. Now making 741 RWHP and still using 1-7/8 kooks headers, kooks off road pipes and stock 2.5 pipes. Thinking it would help some to move to a full 3 inch exhaust?

10-29-2013, 08:55 PM

Quote:

Originally Posted by Criag B

Needed to update this. Now making 741 RWHP and still using 1-7/8 kooks headers, kooks off road pipes and stock 2.5 pipes. Thinking it would help some to move to a full 3 inch exhaust?

Nothing drastic. $/hp you will be disappointed.

JCunningham · 10-30-2013, 01:23 AM

ARH makes a full 3" kit

axis · 10-30-2013, 02:05 AM

Quote:

Originally Posted by Criag B

Needed to update this. Now making 741 RWHP and still using 1-7/8 kooks headers, kooks off road pipes and stock 2.5 pipes. Thinking it would help some to move to a full 3 inch exhaust?

At 700+whp, a full 3in exhaust would have already been on my car.

3rdgen3 · 10-30-2013, 07:17 AM

Waste of money for true dual 3" on these cars.

thahemp · 10-30-2013, 08:52 AM

Quote:

Originally Posted by 3rdgen3

Waste of money for true dual 3" on these cars.

Says the guy without a 3" exhaust.

Craig B · 10-30-2013, 03:09 PM

Quote:

Originally Posted by 3rdgen3

Waste of money for true dual 3" on these cars.

Funny u say that because a guy that dyno's 100's of Camaro's told me he never sees any gains from cars that switched to 3inch exhaust. He has told me when your over 800 +rwhp then it's worth it. Has anyone done any back to back testing switching the 2.5 to 3 on the dyno??

thahemp · 10-30-2013, 03:36 PM

Quote:

Originally Posted by Criag B

Funny u say that because a guy that dyno's 100's of Camaro's told me he never sees any gains from cars that switched to 3inch exhaust. He has told me when your over 800 +rwhp then it's worth it. Has anyone done any back to back testing switching the 2.5 to 3 on the dyno??

Everything I have ever seen says you won't gain much of anything going to a 3". I choose to look at it differently. You don't really lose anything by going with a 3" exhaust either. I think the 3" catbacks sound a LOT better than any of the 2.5" I have heard.

axis · 10-30-2013, 08:12 PM

Quote:

Originally Posted by Criag B

Funny u say that because a guy that dyno's 100's of Camaro's told me he never sees any gains from cars that switched to 3inch exhaust. He has told me when your over 800 +rwhp then it's worth it. Has anyone done any back to back testing switching the 2.5 to 3 on the dyno??

While the 2.5in pipes can handle 700+whp, at that power level, a 3in exhaust will surely help. Think of it another way, Your engine is making around 900 crank hp. Tell me that doesn't deserve a 3in exhaust.

Craig B · 10-30-2013, 08:23 PM

Quote:

Originally Posted by axis

While the 2.5in pipes can handle 700+whp, at that power level, a 3in exhaust will surely help. Think of it another way, Your engine is making around 900 crank hp. Tell me that doesn't deserve a 3in exhaust.

I would agree, hell back in the day a SBC with anything over 500 hp always got 3 inch pipe on it.

axis · 10-30-2013, 08:31 PM

Quote:

Originally Posted by Criag B

I would agree, hell back in the day a SBC with anything over 500 hp always got 3 inch pipe on it.

I agree but I wouldn't hesitate to leave the stock 2.5in piping on a 500+whp car. Once you're boosted and pushing well over 600whp, you NEED a bigger exhaust.

08-20-2013, 03:13 PM	#15
black79ta Drives: 79 transam with 582cid dart motor Join Date: Jun 2010 Location: missouri Posts: 529 View My Garage	I have 1 7/8 kooks, 3×3 cats. Cut off the 2.5 " end of flowmaster AT welded on 3 inch end. 3 inches all the way back. Love it. __________________ 2010 Camaro (inferno orange, 2SS, RS and such) cat backs, catch can, CAI on the way 79 Transam, 582 cid dart motor 779hp 315's out back 40spline gdaxles tko tranny

08-20-2013, 08:04 PM	#17
litle88 V8 Lounge member #2 Drives: 2001 Ws6 Join Date: Sep 2009 Location: Burbank,IL Posts: 6,373	I slapped a Flowmaster 3" catback and center mount exhaust with the kooks and I live it! __________________ 2001 ws6, 40k miles, Ls3 416 stroker, short block built by PER the rest by me. LPE Ls3 heads milled to 12-1 comp, FAST 102, NW 102, kooks 2", dual DMH cutouts, Magnaflow C/B, BTR cam + springs. Full UMI suspension.

10-30-2013, 01:23 AM	#20
JCunningham Drives: 2017 2SS M6 Join Date: Jun 2013 Location: WNY Posts: 7,070	ARH makes a full 3" kit __________________ real ZL1 wheels and brakes, 285/305 Michelin Pilot Super Sports, Pray ported Intake manifold, Soler Throttle Body, Rotofab intake, EFI Tuning Flex fuel kit, full American Racing Headers Exhaust, 1 7/8" w/ cats H pipe and mufflers. Full 1LE suspension, with BMR adjustable sway bars and links, GM aluminum cradle bushings, Hurst shifter with lighter reverse spring, TWM shifter knob, Tick level 1 transmission. I should have bought a ZL1

10-30-2013, 07:17 AM	#22
3rdgen3 10-bolt Destroyer Drives: 2012 Camaro 2SS/RS - AGM, LS3/6M Join Date: Jun 2012 Location: Canukistan Posts: 860	Waste of money for true dual 3" on these cars. __________________ 2012 Camaro 2SS/RS - LS3/TR6060: Cam, Headers, Exhaust, Intake, Gears, Twin Disk, Suspension, Tuned - 475rwhp, 443rwtq

10-29-2013, 08:47 PM	#18
Craig B Drives: 2013 1LE Join Date: May 2013 Location: NJ Posts: 685	Needed to update this. Now making 741 RWHP and still using 1-7/8 kooks headers, kooks off road pipes and stock 2.5 pipes. Thinking it would help some to move to a full 3 inch exhaust?