black79transam

This summer I am going to be installing my 1.75 headers into a ORY. However due to my wifes daily driver needing some repairs the stock catback is going to stay. The original owner replaced the stock muffler with a magnaflow but the piping size is still the stock size (2.5).

How much HP is that likely to cost me vs having a 3" magnaflow catback on the back? Is it something I would even feel? My mods would be the headers, ory, ls6 intake, Ported tb, tb coolant bypass, air/egr deleted, frost tune

JRENIGAR

iTrader: (37)

The stock size is 2.75" and I don't think at your power level you will realize it. The muffler is the most restrictive part of the stock system.

poltergeist 02

iTrader: (65)

I doubt you would be able to tell a difference. You will gain most of your power from the headers/ory and the tune.

black79transam

Thanks guys. That's what I thought but I wanted to make sure.

HCI2000SS

iTrader: (2)

But it will sound way better than it does now

z28SSilvest

Since it's a magna flow it can't be too bad

demonspeed

iTrader: (7)

Just get a cutout if you're concerned

JRENIGAR

iTrader: (37)

Look at the muffler inside the 3" inlet. It necks down to roughly 2.5" right before it makes the first 90deg bend inside the muffler case. Mine does anyways.

MikeWS6

A stock catback with a cut out will make up the difference.

poltergeist 02

iTrader: (65)

He is running a magnaflow muffler with stock piping for the cat back. I dont think this will hurt him in any way at his power level.