I've been waiting to start collecting data on intake air temps with an "open" air cleaner setup of some kind, and a "cold air induction" (stock for later trucks) setup. Rule of thumb is that every +10* of inlet air temp is 1% loss of power. All of the TPI setups (and TBI car) use a manifold air temp sensor. Pretty easy to gather the data with that. So far, with engine coolant temp in the 195-210* range, (varying due to fan on/offs) manifold air temp with "cold air induction" and approx. 85* ambient air temp, manifold air temps were consistently 80* cooler than coolant temp. Next test will be to remove the cold air setup, and try to move the air inlet closer to the engine. Kinda tough on mine with the MAF sensor, but I'll try my best. Anyone with MAP TPI and a filter on the throttle body and a scanner that wants to try this, will be closer to the engine than what I'm likely to achieve. One other thing I just thought of, cooling fan is going to make a difference. Electric fan setups don't measure underhood temps, so engine bay cooling never changes until coolant temp gets high enough to activate the fans, while a clutch, flex or electric fan on a switch will likely decrease underhood temps. Guess I'll have to test that too. I'm sure this is pretty pointless to most, but I figure I'll share what I find in case it's of interest to anyone else. Everyone knows cooler air makes more power, just a question of how much cooler we are talking about.