Ben, My last dyno runs were done on DD. For testing and self satisfaction purposes i had the operator put the air intake sensor both out side the car in ambient, and next to the air filter. The air filter position made 2 more whp, and the inlet temperature rose 6 degrees celcius. Although in my sitation 2hp is nothing, but i think it reflects the engine more accurately - as you need to account for what temp air the engine is really sucking in.