ssdungeon

iTrader: (24)

I have a borla on the Z with 3" piping up to the borla. I have a regular cutout right before the borla. If I get a cutout FOR the borla its only a 2.5"
If I use the cutout before the borla I can use a 3". So my question is with say on gas a 700hp motor would that 2.5 be enough? I know it will actually have the 2.5 PLUS whatever else can blow through the muffler after the y for the borla. There is no cats or anything on the car.

I am about to redo the piping under the car and wanted to cut that cutout off. It drags often since the car is lowered in the front. However I would much rather have enough flow.

There was a thread here with exhaust size vs. power but I cant find it. I remember a straight 2.5 was good for a lot of HP back in 2002 when I read it.

CamaroSS27

iTrader: (6)

Its easiest to do the cutout before the axle so you have 3" cutout.

ssdungeon

iTrader: (24)

Yes the cutout is already there and I know I can add one there but man its so low already and on previous LS1 cars I have always had issues knocking the motors off the cutouts. I know you can install one right between where the borla connects I just wanted to know if that would be enough flow since its 2.5" plus whatever can go through the actual muffler.

Blk98Vert

iTrader: (2)

The borla is straightthrough, you essentially have a cutout on a straight pipe, there is no point. The cutout made for the borla is there to either divert flow into the muffler so its quiet or bypass it so that It's loud. If I were you though I'd ditch the Borla and buy some True duals asap, you are easily giving up 20 rw by running a single 3 inch system