N55 midpipe input needed

[parky1215]

I currently have iCarbon catted downpipe and Berk resonated midpipe sitting in my garage waiting to be installed.

I am going to install them as soon as I decide on which axleback to go with (maybe quad exhaust).

My car is N55 2011 135i so stock midpipe doesn’t have cats like N54 (only has resonator at the end).

I am wondering if I should replace stock midpipe with Berk midpipe.
Berk midpipe is mandrel bent and probably has better flowing resonators than stock.
But I am not sure how much HP I am going to gain by changing stock midpipe to Berk with my setup.

Should I sell Berk midpipe and spend that money on something else?
Or should I put Berk midpipe along with other components (downpipe, axleback)?

[Turbolader]

If you decide to replace your midpipes, please PM me, I might be interested.

I'm sure the Berk ones are better, but by how much, I don't know. I think the mandrel bends will help, but more than likely the bigger reason would be the resonator. I read the stock resonator is fairly restrictive.

[Aries932]

I have just done the Berk Midpipes and there is really no difference besides a a bit better tone coming out of the exhaust. That might change with adding on downpipes because you will be allowing much more air flow to go through the pipes. Either way it is not going to make much of a difference...maybe 2-3hp on the midpipes. The downpipes are going to make a huge difference.

[shockin330i]

Change the downpipe first. You might like the sound and not want to change the exhaust.