We've been kicking around an N55 intake project and decided to strap the car down for a little testing. Our N55 intake design is going to be pretty nifty. 5 minuite install/removal, low cost, awesome sound, and the best flow of any N55 intake out there. We reuse the OEM airbox bottom which does a great job of insulating radiant heat and ducting flow and then remove the restrictive part (the lid) allowing our new exposed filter an ample air supply.
The test car is our 135i DCT with Stage2, BMS DP, BMS chargepipe, WW meth (50/50), BMS prototype intake, and 93 octane.
Intake gains at the stock boost levels were non-existent but at higher boost levels there was a small gain. Oddly we saw a higher delta gained on map 2 than on map 3. Perhaps some other contributing factors there. But net/net I'm confident saying we'll be able to deliver 5-10hp gains. That is simply all an aftermarket intake can add to a higher boost N55 at this point. But power gains aside I think many will find this worthwhile for the sound improvement alone.
At the higher boost levels on map 3 we ran in to more transmission slippage. Sigh. But still managed to take the N55 dyno record. I really need to put an intercooler on the car one of these days and go for 400rw.