swapping in an lq4 with a tr224 cam and ported heads, i'll probably be running 1 5/8 in mids going to a 3.0in collector. I want to run a cutout and will need a cat and magnaflow muffler. and i'm planning on running a single exhaust. my only question is what size pipe I should make this. originally I was going to do a 5.3 and just run a single 3", but since going to the 6.0 I have been thinking about going 3.5.

my setup will go:headers, Ypipe, cutout, cat, muffler, stock exit(right side after tire)

let me know what you think

 

i think 3" will be enough but im not an expert on this

 

I say 3" will suffice, if its going to be driven on the street. And if your adding cats it probably is.

 

115 cfm per in squared..........@ 2.2 cfm/hp........

(1.5 x 1.5 x 3.14 x 115)/2.2 = 369 Hp with a single 3 "
(1.75 x 1.75 x 3.14 x 115)/2.2 = 502 hp with a single 3.5" .........although 3.5 " mufflers are harder to find..........why not go with 2.5" duals?
((1.25 x 1.25 x 3.14 x 115)/2.2) x 2 = 512 hp......much easier to find tubing, mufflers, cats......and you can always do a twin side exit.....it would sound similar

Nate

 

that was what what I was looking for! i'll take a look at the dual, but if the dual 2.5 would perform the same as a 3.5 single then why bother with trying to stuff everything in, and end up paying more? And I've already found mufflers and cats to choose from, the only thing I cant find is a y pipe that I like.