proper exhaust for a 5.3

[71chevystep4x4]

I'm just curious to what all you other 5.3 swappers are running size wise for exhaust? My headers are Hooker block huggers that were a LS1 application with 2" reducers, and I originally figured I'd run 2 1/2 dual pipes with a H pipe, but would like a final opinion on if just 2" would be adequate.

[Kim57]

I'm no expert but everything I've seen says the LS engines like large pipes.
I'm planning on running 3" exhaust on my LS-2.
Kim

[crazy longhorn]

I think I would go 2 1/2" on the system on the 5.3. The headers no doubt, have a 2 1/2 " outlet.....ditch the reducers, & opt for a set of weld rings? Then you just carry the 2 1/2, right off the collectors....(the way I plan to do my swap....dollars still pending) crazyl

[clinebarger]

2 1/4" would be fine on a 5.3, Are you sure the reducers are 2"?

[mcmlxix]

Factory 2010+ Camaro 6.2L LS3 exhaust manifolds have a 2.5" outlet.... I have a set for my 6.0L LQ9 going into my K5 Blazer. I had a set of exhaust flanges cut out of 3/8" steel on a cnc waterjet. The Blazer came to me with 2.25" exhaust with flow masters. Since the mufflers are still good, I will just reduce it at the muffler. I will eventually change them out but not spending the money now....

[Clyde65]

I thought most trucks had single exhaust that was 3inches. I would think stock 6.0 would be fine with dual 2-1/2" easy and give it max breath-ability.

[Wasted Income]

My 5.3 had a 5" exhaust on it for awhile....(coming off the turbo )

When it was N/A I had stainless JBA shorties, dual 2.5" thru magnaflows.
Here's a sound clip

5.3 Burnout

[OKGMC4]

I sized mine using this chart...

http://www.dynomax.com/assets/2008ca...enginesize.pdf

According to that, dual 2.5 exhaust is good to at least 350 hp with turbo mufflers. Most 5.3 engines are somewhere around 300hp.

[71chevystep4x4]

Yeah I was really surprised that they are only 2", they taper right below the flange, I'll probably just cut them there and weld on some 2 1/2 pipe and reweld some O2 senser bungs I guess.

[68GMCCustom]

I just found that the Hooker exhaust manifolds are also 2.25". Seems small.

[mcmlxix]

HOLY BIG PICTURE Kurt .... lol

714x4... Is it just the reducer thats small or is the actaul manifold outlet small? Can you just replace the collector?

[71chevystep4x4]

Its just the reducer, I'll probably just cut it at the taper and weld 2 1/2 on it. The headers are intended for ANY tight fit LS swap application, maybe they just sized them down for that. I just asked because I really didnt want to run 2" pipes.

[68GMCCustom]

Originally Posted by mcmlxix

HOLY BIG PICTURE Kurt .... lol

714x4... Is it just the reducer thats small or is the actaul manifold outlet small? Can you just replace the collector?

You must have post when I was still in the "editing" phase. Didn't have a clue it was going to distort the page like it did....then couldn't find a "reasonable" size pic...just the thumbnail.

odd name for a pic size.................thumbnail.