Originally Posted by HP Autowerks
In our experience upgrading just the IC will likely not get you any HP gain on the 1M and often you will end up with a bit less. However, when combined with a tune then it's a different story.
ETS has been proven to support around 400 whp without high IAT's. Wagner will be tested next. 7" IC's will obviously support more hp at the expanse cutting up the core support for the install.
I agree. My car is mapped and before the N55 mids and Forge it made 402bhp. With the mids and Forge without any chances to my map, it made 425bhp. Tweaking the map to take into consideration the changes, it made 431bhp. All of these figures are at the hub.