1999 Pontiac Trans Am - 5 Performance Modifications - Take The Money &Run

On the airdam, more flow will be seen by removing an area as wide as the slot down to the ridge. Use your choice of weapons-a jigsaw blade or a sharp utility knife will do the job, but a die grinder with a cutoff wheel works best-to cut a rectangular chunk out of the plastic as seen here.

For the radiator support, leave the filter tray installed as a loose guide and mark around the insides of each square. Pull the tray out and grind away the two squares in the center area of the support.

Your finished support should look something like this-and will flow a ton more air.

With the MAF off the car, now is a good time to remove the screen for maximum flow. There are no snap rings holding the screen in place, so you can gently push it out the back of the mass airflow sensor. Be sure to avoid the three elements in the center of the MAF; any damage done can cause serious problems. Be sure there is no extraneous debris in the sensor before replacing it. Once that is done, the MAF can be placed back into the intake tract resonator and the hose clamp can be tightened down.

A home-ground throttle body is an easy way to get more air into the Gen III engine. To perform this procedure, unhook the throttle position sensor (TPS) and idle air control sensor (IAC) connectors from the throttle body. The throttle cable and coolant hoses are removed also, then the three 10mm bolts holding the throttle body were removed.

The TB was taken to a workbench and mounted in a vise; a carbide bit and some 80- and 120-grit paper rolls were waiting for it. Porting the Gen III's throttle body is done to remove a restrictive ridge in front of the throttle blade and to generally make the contours smooth. You want to take out the turbulence and increase velocity, but don't go hog-wild because the carbide bit can burn through pretty quickly. Use the 80-grit to smooth out the carbide burr cuts, and the 120-grit to polish the throttle body smooth.

Any sharp edge on the throttle body should be buffed down. "Make it smooth and curvy, like a fine woman," suggested SLP Chief Engineer Brian Reese. Mmm, curvy. Anyway, don't do heavy porting in the idle air bypass area-that will force air into this spot that doesn't need any more.

Mild port work is performed on the back side as well, and the throttle blade screws are ground down. Once the TB is cleaned up, it is ready for reinstallation.