Throttle and cruise control...
Throttle and cruise control cables are removed from the throttle assembly by rotating the assembly back and pulling the cable connections out of their mounts.
The idle air control (IAC)...
The idle air control (IAC) sensor (top) and throttle position sensor (TPS) are unclipped from the right side of the throttle body. Three 10mm bolts that attach the throttle body to the intake manifold are loosened with a 1/4-inch ratchet and deep 10mm socket. Then the EGR hose that is connected to the throttle body is removed by pulling back on it until it clears the fitting. Finally, the three 10mm throttle body bolts can be removed.
With the throttle body turned...
With the throttle body turned upside down, pliers are used to squeeze the factory hose clamps, thus allowing removal of the coolant lines to each side of the throttle body. Now the throttle body can be removed and stored.
The single 10mm bolt that...
The single 10mm bolt that retains the EGR tube in the LS1 intake manifold is removed next. Note how the LS1 EGR tube disrupts the flow of air in the intake manifold by sitting directly behind the exit of the throttle body.
Follow along as we install an LS6 intake manifold on a '99 Trans Am and then supplement the manifold swap with an aftermarket lid and ported throttle body. Don't worry, as all of the free and low-buck modifications will be performed, with the exception of the airbox mod. Since the airbox mod modifies the airdam and the lower airbox, it is best intended for those drivers whose vehicles will never see the elements, specifically rain.
In Part II, before-and-after dyno pulls will be completed to document the stock car and the impact the LS6 intake, aftermarket lid, and ported throttle body provide to the overall power increases. With a lofty goal of a minimum of 20 rwhp, we have our work cut out for us.
The '99 T/A is owned by Kadin Betts, a graphic designer from Carrollton, Texas, who uses the car as his daily driver. This black, six-speed beauty was picked up used in 2004 for under $9,000 and has racked up only 57,000 miles.
Installation and testing of the modifications were done at Real Performance Motorsports in Lewisville, Texas. Real Performance Motorsports specializes in late-model General Motors performance, and can take care of all of your Firebird, GTO, and Grand Prix needs.
Free Mods (And Low-Buck)
Descreen MAF - Screen is removed from MAF in theory to increase airflow, $0. Real Performance Motorsports and many other shops do not recommend this mod Cut EGR Tube in LS1 Manifold - EGR tube is cut down in intake manifold to increase airflow, $0 Airbox Mod - Factory lower airbox and airdam are modified to pull more air in from underneath the car, $0 Throttle-Body Coolant Bypass - Engine coolant is not routed to the throttle body, thereby allowing for a cooler charge $5-$15 Ported Throttle Body - Throttle body either home ported and polished or sent out to a service provider, $0-$300Cost-Effective Mods
Aftermarket Air Filter, Factory Type - Factory-style paper air filter replaced with a drop-in filter utilizing a cotton gauze or foam element to increase airflow, $25-$50 Aftermarket Airbox Lid - Lid replaces factory upper airbox assembly to increase airflow $75-$150 LS6 Intake Manifold (with or without EGR provisions) - LS6 intake manifold to increase airflow, used or new parts, $300-500Recommended Tools
Metric socket set Metric wrenches Flat-bladed screwdriver Schrader valve tool Fuel-line disconnect toolRecommended Parts And Supplies
SLP LS6 Manifold (with EGR provisions), PN 30041, $499.95 SLP LS6 Manifold (without EGR provisions), PN 30039, $399.95 GM Manifold Gaskets, PN 12533587, $76.30 GM LS6 Intake Manifold, PN 12561269, $851.46 GM Throttle Body Gasket, PN 125525.42, $12.06 Shaner S2 Throttle Body, Exchange, $119.95 satin finish, $139.95 polished Motorsports Technology Inc, Carbon-Fiber-Look Airlid, $129, K&N filter $49Stay tuned for Part II, where we will complete the bolt-on installations and dyno test the T/A.