N55 135I 2013 Gutted Downpipe

Kheadley · 03-07-2019, 11:17 AM

Has anyone Gutted their downpipes? Im not planning on ever selling the car and if I can get the same effects as a bought catless downpipe then ill do that.

tracer bullet · 03-07-2019, 11:33 AM

First, I have not. That said, I do have some things to suggest you consider:

Is the factory cat a restriction, or is it the shape of the pipe at any particular location that is the real restriction

Will you cause any flow issues - sudden expansion (and cooling and higher density) of the exhaust gasses?

Any flow issues due to turbulence?

Gutted might be "better" (i.e. higher power resulting). But don't assume it'll be better.

03-07-2019, 11:17 AM	#1
Kheadley Private 16 Rep 87 Posts Drives: 135i Msport 2013 Join Date: Jan 2018 Location: Canada, Saskatchewan iTrader: (0)	N55 135I 2013 Gutted Downpipe Has anyone Gutted their downpipes? Im not planning on ever selling the car and if I can get the same effects as a bought catless downpipe then ill do that.
	Appreciate 0 Tweet Quote

03-07-2019, 11:33 AM	#2
tracer bullet Brigadier General 2382 Rep 3,525 Posts Drives: '11 135i , '15 X3 35i Join Date: May 2011 Location: Saint Paul, MN iTrader: (1)	First, I have not. That said, I do have some things to suggest you consider: Is the factory cat a restriction, or is it the shape of the pipe at any particular location that is the real restriction Will you cause any flow issues - sudden expansion (and cooling and higher density) of the exhaust gasses? Any flow issues due to turbulence? Gutted might be "better" (i.e. higher power resulting). But don't assume it'll be better.
	Appreciate 0 Quote