2.75" vs. 3" exhaust

joeyz71 · Post by **joeyz71** » Tue Jul 17, 2007 11:29 pm

OK, here's the deal. I had my last truck, an '01 5.3 supercharged Silverado and put a 3" Flowmaster exhaust kit on it. I now have an '03 and it's gonna get identical mods ( K&N filter, supercharged,Gibson 1 5/8 primaries, Diablo and 3" exh maybe). Now, the stock exhaust is 2.75" and I can just get a Flowmaster muffler for it and save about $200.00. So, is the 1/4" increase from the cat flange back worth $200.00?

The pipe b4 the flange is 2.75" anyways so the main advantage I guess is the expanding/scavenging properties that the step up in size offers too (kind of like a dirtbike).
I don't want to be cheap or anything, but don't have $ 2 burn either.

LightningMike03 · Post by **LightningMike03** » Wed Jul 18, 2007 1:46 am

If you have a mandrel bend system and are only at 6lbs boost, you are going to be fine at 2.75".

madmanwithmouse · Post by **madmanwithmouse** » Wed Aug 01, 2007 10:56 pm

a note tho... if you double the dimater, you quadruple the flow.

joeyz71 · Post by **joeyz71** » Thu Aug 02, 2007 10:22 pm

Yeah, but it just sucks that it's a cross over pipe after the cats, to the to the single flange that feeds the single inlet to whichever system I go with and either single or double out. I mean I can easily spend hundreds of $ and the crossover is still going to be my biggest restriction. But, I just may decide to go with the dual out near the rear bumper. If I'm gonna do it, it may as well look good to me when I'm walking up to my truck. To hell with what anyone else thinks.