Correct me if I am wrong, but the oem intake is a fresh air intake, and not a true cold air. IIUC, a true cold air intake system prevents the engine operating temps from effecting the intake temps until the air reaches the throttle body. The intake filter systems that replace the oem air box while they flow more air, they are also flowing heated engine air. This heated air is often why the performance gains claimed by the manufacturer are rarely seen when the system is enclosed in the car. IME(not w/a Supra), there is a seat of the pants performance difference between the two systems, since the air remains at outside ambient temperatures. The one test I did w/the set-up I have in my truck there was a 40* drop in intake temps before and after the modification.