I've been in the market for a downpipe back exhaust and was leaning toward the AWE because of the sound. However, the 2.5" diameter tubing seems too small.
I noticed many aftermarket exhausts for 2.0L engines have 3" mandrel bent tubing. I was wondering why most manufacturers of F56 aftermarket exhausts are using 2.75" rather than 3". And AWE is using 2.5".
I understand most of the gains are due to the removal of the secondary cat. I think the larger diameter piping would also result in additional power.
To my understanding. Smaller tubing increases the velocity of the gasses and keeping turbo response. Removing cats are the important part. 3inch is over kill.
Even on my Stage 3 R56 with a 45mm turbo, I had a 2.5in exhaust.
I ran a 3.5 on my high hp evo x there really wasn't much difference besides sound and better increase in top end at high rpm but I never put it on the synopsis after upgrading. I agree with the above its overkill and will probably even make it feel sluggish in certain areas of the power band unless it's a pretty high hp mini. This was the 3.5..