2.5 vs 3 inch exhaust - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

SSINSTR · 07-28-2009, 06:15 PM

I have been looking at the MBRP and the Borla catbacks and the main difference to me is the MBRP is a 3 inch and the Borla is a 2.5 inch. They both sound great, and at least for now are about the same price.

My question is this... Do our cars flow enough exhaust to warrant the 3 incher or is 2.5 sufficient? I plan on eventually going H/C with this car but probably no blower. Thanks in advance.

ZZcamaro · 07-28-2009, 06:44 PM

As long as you change the whole catback to some smooth 2.5 inch you should be able to support 500RWHP. with 3 inch you will be better off though, and can support much more.
The headers and stock cats will be your weak point and will somewhat limit what you can do.

CGM2SSRS · 07-28-2009, 07:12 PM

Let me expound on zz, if you plan on modding over 500hp to the ground, do the 3". If not, to keep the back pressure I would go 2.5".

ZZcamaro · 07-28-2009, 08:16 PM

Quote:

Originally Posted by CGM2SSRS

Let me expound on zz, if you plan on modding over 500hp to the ground, do the 3". If not, to keep the back pressure I would go 2.5".

absolutely agree 100%...well said

PatrickfromMD · 07-28-2009, 08:35 PM

Headers, 1 7/8 or 1 3/4?
At what point will the 1 3/4 be limiting you?

CGM2SSRS · 07-28-2009, 08:57 PM

If you have a finely engineered set of 1 3/4" LT's they will dump as well as a most 1 7/8" LT's. It's all about R&D. Go with what has been proven through testing. We have a few quality LT'S listed on this site. Proven. If you want to match an equally designed set of 1 7/8 vs.1 3/4 again I will use 500hp to the ground as a bench mark. The bigger might realize two tenth's in the quarter improvement. Maybe. Double that power and the difference will be substantial.

SSINSTR · 07-29-2009, 01:13 PM

Sounds good, had this debate with the last car and the verdict was 2.5 gave more torque while 3.0 was a little more top end with a slight sacrifice in torque. I think if I do 1 7/8 LT's the 2.5 would be fine for the power levels I am looking for.

ZZcamaro · 07-29-2009, 01:15 PM

Quote:

Originally Posted by SSINSTR

Sounds good, had this debate with the last car and the verdict was 2.5 gave more torque while 3.0 was a little more top end with a slight sacrifice in torque. I think if I do 1 7/8 LT's the 2.5 would be fine for the power levels I am looking for.

I think you got it right on!!! You should be in good shape with the Longs and the 2.5

Have fun!! I fyou need any help let me know.

07-28-2009, 06:15 PM	#1
SSINSTR Michelin Man Assassin Drives: '10 IBM 2SS/RS LS3 Join Date: Feb 2008 Location: The Lone Star State Posts: 217 View My Garage	2.5 vs 3 inch exhaust I have been looking at the MBRP and the Borla catbacks and the main difference to me is the MBRP is a 3 inch and the Borla is a 2.5 inch. They both sound great, and at least for now are about the same price. My question is this... Do our cars flow enough exhaust to warrant the 3 incher or is 2.5 sufficient? I plan on eventually going H/C with this car but probably no blower. Thanks in advance. __________________

07-28-2009, 08:35 PM	#5
PatrickfromMD Drives: Buick Enclave/Corvette/2010 Camaro Join Date: Aug 2008 Location: Maryland Posts: 421	Headers, 1 7/8 or 1 3/4? At what point will the 1 3/4 be limiting you? __________________ *56K miles and still going strong* 2SS/RS IOM ext w/cyber grey stripes, tinted windows, IO int Auto ProTorque prototype Converter, Chuck Mosello of Westchester Corvettes Custom Tune T&T installed SLP Longtubes, Powerflow X Pipe, and Powerflow axle back JL 10W3 in custom side sub box, new door tweeters, Alpine 5ch 600 watt T&T configured ACS front Fascia w/ heritage grill, splitter, dual color halos, , led markers, taillight bezels , all accented in CGM Gary Custom Z vented fenders. Vararam ver 2

07-29-2009, 01:13 PM	#7
SSINSTR Michelin Man Assassin Drives: '10 IBM 2SS/RS LS3 Join Date: Feb 2008 Location: The Lone Star State Posts: 217 View My Garage	Sounds good, had this debate with the last car and the verdict was 2.5 gave more torque while 3.0 was a little more top end with a slight sacrifice in torque. I think if I do 1 7/8 LT's the 2.5 would be fine for the power levels I am looking for. __________________

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07-28-2009, 06:44 PM	#2
ZZcamaro Drives: 2SS w/ ZZ427 Package!! Join Date: Oct 2008 Location: Pittsburgh, PA Posts: 2,700	As long as you change the whole catback to some smooth 2.5 inch you should be able to support 500RWHP. with 3 inch you will be better off though, and can support much more. The headers and stock cats will be your weak point and will somewhat limit what you can do.

07-28-2009, 07:12 PM	#3
CGM2SSRS susp.ban4life! Drives: Raptor Join Date: Jun 2009 Location: Notinsuspensionthread Posts: 943	Let me expound on zz, if you plan on modding over 500hp to the ground, do the 3". If not, to keep the back pressure I would go 2.5".

07-28-2009, 08:57 PM	#6
CGM2SSRS susp.ban4life! Drives: Raptor Join Date: Jun 2009 Location: Notinsuspensionthread Posts: 943	If you have a finely engineered set of 1 3/4" LT's they will dump as well as a most 1 7/8" LT's. It's all about R&D. Go with what has been proven through testing. We have a few quality LT'S listed on this site. Proven. If you want to match an equally designed set of 1 7/8 vs.1 3/4 again I will use 500hp to the ground as a bench mark. The bigger might realize two tenth's in the quarter improvement. Maybe. Double that power and the difference will be substantial.