180ls1

iTrader: (4)

I just measured today where my magnaflow 3" cat back clamps over the factory y and the outlet from the factory y pipe where it merges is 2 5/8" so my thinking is to cut off that part where it necks down to 2 5/8" and cut it back till where it is 3" and then weld a replacement 3" pipe straight to the 3" magnaflow cat back. Should i see a worth while gain? i know it wont cost much or take much time. Or does anyone have any pictures of someone else doing this? Thanks

bww3588

iTrader: (49)

no. it wont be worth your money, even if its free.

Cumbias

Do you have plans on replacing the y-pipe to a 3-inch. Id say do it but only if you get a new Y.

orangeapeel

iTrader: (18)

I would stick with what you got. You may end up being pissed at yourself for messing up your current setup.

Deeavi

iTrader: (16)

Just Do it! I have done it to several systems. Any improvement in flow is an improvement in flow.

tylerdj

iTrader: (31)

PewterScreaminMach

iTrader: (7)

x3 on this one.

180ls1

iTrader: (4)

I just saw this. So i knew i am losing power i just dont know how much, so i would imagine 2 5/8 is good for no more then 275 or so without loss

quoting JRP:

A 2.75” (stock) single system is good for a 310hp engine with zero loss…
A 3” Single system is good for a 370hp engine with zero loss…
A 3.5” Single system is good for a 503hp engine with zero loss…
A 4” Single system is good for a 657hp engine with zero loss…
A 2.25” dual system is good for a 457hp engine with zero loss…
A 2.5” dual system is good for a 513hp engine with zero loss…
A 3” dual system is good for a 812hp engine with zero loss…

LS1crazy01

iTrader: (14)

I'd say just do it! I had it like that from day one when I put my flowmaster together. My cousin gave me his old Y pipe I think it was SLP or somthing and then bought a flowmaster muffler and made my own cat back. It sounded great! Heres a pic of the Y pipe.

DarkJuggalo

iTrader: (6)

a single 3" is only good to 370 ouch...

bww3588

iTrader: (49)

not worth it still, the round 2 5/8 pipe flows better than the drivers side flat pipe..... if you want to do anything to the stock pipe, replace the flat part. otherwise just wait it out untill you get headers and get a full 3 inch Y-pipe. id say your losing all of about .5 HP with the smaller pipe in the I, but your losing .75 in the flat part of the drivers pipe.

i mean, if you want to do it still, more power to you. but your pissing into the wind. i garuntee, you will notice nothing, and even if you dyno it, you will see nothing because the variances in conditions and dyno's will outweigh the results.

180ls1

iTrader: (4)

hell ya that is what i was looking for. Thanks, and after seeing that chart i think it would definately be in my best interest to do that mod.

5301113

iTrader: (18)

Do it . Do it

JEB99TA

iTrader: (32)

Why not just pay $40 bucks for a Flowmaster Y merge to replace the stocker with?

180ls1

iTrader: (4)

would i see worth while/money gains from that vs a $5 piece of pipe? I was thinking about it but i will look into it more.

bww3588

iTrader: (49)

your not going to see jack **** from any of it, so why bother?

5_02ls1

iTrader: (20)

better idea...

pacesetter longtubes
custom 3"ory into a flowmaster merge
and a cutout

xBROKEx

iTrader: (7)

not worth the effort

180ls1

iTrader: (4)

california

and i have a cutout installed

bww3588

iTrader: (49)

ok....were trying to keep you from hacking up your stock Y thinking your going to gain something.

1. shorties or if your on a budget, get 00+ manifolds
2. 2 high flow cats and put them in the same place as your stock cats
3. SLP Y-pipe, that doesnt have the flat peice on the drivers side
4. if your really worried, get a flowmaster merge and do the mod on the new pipe. but the stock merge is more than sufficient for stock manifolds and a cat back.