karpetcm

iTrader: (2)

I have a 2 1/2 inch ypipe right now and stock piping with just a hooker muffler. Is it worth changing everything out to a 3 inch, ypipe and catback exhaust. I was thinking of doing that and putting on a underdrive pulley to pick up a few more ponies but not sure if its worth it doing that. What do you guys think.

99SSJarhead

iTrader: (2)

It shouldn't be to expensive to do and it'll help a bit. I'm not good with dyno numbers, but better flow out of the engine is a good thing and as you improve the engine your numbers will increase because of the exhaust flow.

Darkman

iTrader: (2)

A 3 inch pipe flows 60% more than a 2.5 inch pipe of the same shape and length. A drawback of an underdrive pulley is its effect on the driven accessories, but since you have 4.10 gears you probably can use an underdrive pulley without issue.

karpetcm

iTrader: (2)

damn i didnt know it was 60% better flow, thats pretty decent flow for going to 3inch piping.

Tyler Z28

iTrader: (1)

i think you hold off on both and do an ls6 intake and a dyno tune, the HP per dollar will be alot better.

omarrakeen

iTrader: (2)

on headers or stock manifolds? input more details. from your mods in sig. it says bbk LTs, i know for a fact they are 2.5". going to all 3" requires cuting your collectors(i think) or its still going to be a restriction. you can also consider a 3 inch merge?...but over all with headers and 3" all the way id say yes its worth it, other than that id spend the money somewhere else.

gocartone

iTrader: (4)

If you're sticking to a Y-pipe there is no reason to go to a dual 3" Y into a single 3", I would put a 2.5-3" merge on it and a full catback. Two 2.5" pipes flow slightly better than one 3.5" does, so if you are going to stick a 3" catback behind them there is no reason to go with 2 3" into 1 3".

karpetcm

iTrader: (2)

I thought most 3inch ypipe's will fit most LT's. I know the ypipe that came with the BBK LT's are 2.5's but the connection wether its 2.5 or 3inch should fit right up to the headers i think but im not sure maybe someone can chime in that knows it for sure. On the other comment above i have an 01 Camaro doesnt that have the LS6 meaning 01-02's.

gocartone

iTrader: (4)

Yup you have the LS6 intake already, and it wouldn't make sense to go with a 3" y-pipe into a 3" catback, you will gain nothing over the 2.5". The only way a 3" Y will help is if you go to a 4" catback. I'd just get a 2.5"-3" flowmaster merge with a 3" catback and call it good.

senicalj4579

iTrader: (41)

You should just start buying your **** for 4" ory all the way through or duals. If your puting out 350 to the wheels then your engine is already at that point where it will benifit from going bigger than 3"

gocartone

iTrader: (4)

That's what sucks about these cars, I wish they would have came with duals from the factory. $1600 for the Kooks duals is too much, and dumped duals is way too loud in the car.

99Bluz28

iTrader: (35)

The 3" outlet on the merger is your restriction, not the 2.5" pipes.
I'd just change the Y-pipe merger to one with 2.5" inlets and 3.5" outlet.
That what I'm getting ready to do, once I have all the exhaust parts I ordered.

z99ls1

iTrader: (12)

Get a cutout for $25 from summit lol

Darkman

iTrader: (2)

I agree. 3" pipe flows only 80% of what a pair of 2.5" pipes will flow, but a 3.5" pipe will flow 19% more than a pair of 2.5" pipes.

gocartone

iTrader: (4)

Are you sure? Where did you come up with that? A pair of 2.5" pipes have an area of 9.82" vs 9.62" for a 3.5", I would think that they would flow better then? Unless I'm missing something about how exhaust flows, but I would think more area=better flow on something like exhaust.

Darkman

iTrader: (2)

https://ls1tech.com/forums/14998142-post23.html

https://ls1tech.com/forums/generatio...e-worried.html

usafws6

iTrader: (10)

i make 450rwhp and only have a 3in ory and matching magnaflow catback. i wish i had the cash to upgrade to 1 7/8 and duals or big custom y and cb. the ops money could be better spent on a cam.