Some user submitted videos of a midpipe only swap on a 135i. The 1M is different but similar enough to draw some useful comparisons on how it will sound on the two cars.
"I had a BMW 135i 2010.
I wanted exhaust note louder than stock, but not too much.
So I looked for BMW PE, but it's too pricey..... about 1500$ and only 3 hp more.
I decided to bought Berk Midpipe. 600$ and 10-15 hp more to the wheels. (http://www.jlevistreetwerks.com/1-Se...duct_info.html)
And, I think downpipe are too lood for me...
So , I lift my car with Jacks and install the midpipes.
It was not easy and not hard, but took to me about 2-3 hours with one beer break... I don't have a lot of sapace to work and nuts are difficult to unscrew.
Berk Midpipes fit perfectly and all you need come in the box. They seems to be very solid and well made. They are also more lightweight than stock midpipe.
Installation was succesful and I record one video with sound before and two more after.
This is the perfect thing to give a looder sound than stock, but not too much. I keep my stock downpipe and my stock exhaust.
Sound is very close to stock when at idle. But, when you start accelerating, the exhaust note is beautiful, but not too much. It's not like a fucking Honda Civic exhaust pipe. It's a V6 sound. Just enought and not intoxicating. You can heard it in the cabin. It's like my friend's G37 exhaust, but louder in hard accelerating.
Shipping was fast and service very good....
If you want more sound but not too louder, go with this upgrade."