Maybe he drove better in the race. Maybe he has more mods than he told you. Could be alot of things, but like the other guys said, that IM and TB isn't helping you out in making your car faster. An aftermarket intake and TB on an engine with stock cams and a stock valvetrain is slowing down your intake airflow speed, your not reaching peak volumetric efficiency until much higher in the rpm range, if your even hitting it at all. Your increasing the volume of air but slowing the down speed of the air. The stock cams can only feed a finite amount of air to the cylinders, the valves are only being lifted so high and kept open for so long. You need higher lift cams that hold the valves open longer and lift them higher to feed all this air into the cylinders that your IM and TB are giving it.
What IM are you using, and what size TB? Is the diameter of the TB and the diameter of the IM's intake port the same?