2000 WS6 Trans Am LS1 Power Plan Part 1- Pontiac Tech

Removal of the LS1 manifold is relatively easy. The band clamp that connects the LS1 Motorsports lid to the BBK throttle body is loosened and the snaps holding the lid to the airbox are unsnapped. After removing the lid, various sensors, including the intake air temperature (IAT), mass airflow (MAF), idle air control (IAC) and throttle position (TPS), are disconnected from the throttle body. The PCV valve is disconnected by pulling it free of the throttle body, and the intake manifold ground strap is removed with a 10mm socket.

Throttle and cruise control cables from the throttle body assembly are unhooked by rotating the throttle back by hand. The wiring loom is pulled out of the retainers on both sides of the manifold, as is the fuel system EVAP hose that runs from the driver-side fuel injection rail to the intake manifold. All eight of the fuel injection connectors are unplugged. EGR tube removal is simple, as a single 10mm bolt secures it to the manifold. There are ten 8mm intake manifold bolts total that have to be loosened (shown), but only the front six-bolts can be removed due to interference with the cowl on the rear bolts. All wires and connections to the outside of the manifold are disconnected, as is the hose at the power brake booster.

After the EGR tube is moved out of the way, with a helper, the manifold is lifted upwards and forward approximately 6 inches. Behind the manifold, the electrical connection for the manifold absolute pressure (MAP) sensor and the vacuum line beside the sensor are disconnected. Then the intake manifold is lifted out of the engine bay.

After the fuel rails, injectors, throttle body, and throttle cable bracket are transferred to the new SLP LS6 manifold, with the four back bolts in the holes, it's carefully lifted into the engine compartment and pushed far enough back so that the MAP sensor, brake booster hose and vacuum lines can be attached. The manifold is then pushed into position and the remaining intake bolts are inserted and hand-started. The 8mm intake bolts are snugged down with a 1/4-inch air ratchet before being torqued to 44 in-lb on the first pass, followed by a final torque to 89 in-lb. The bolts are torqued using a specific tightening sequence that starts on the center bolt of the passenger side, then goes in an alternating bank pattern from left to right and from front to back.

The LS1-style front and rear bypass tubes can't be reused, as insufficient space exists for the tubes to connect under the LS6 manifold. After removing the tube assembly with a 10mm socket, the wire loom that houses the wiring for the front and rear engine knock sensors (black rubber plugs in valley pan) is separated, then a razor blade, grease, and wax remover are used to thoroughly clean the head surface. Included in the SLP kit are GM's new front bypass tube, rear block-off plates, and a new hose. The new replacement hardware is installed (shown) and the front hose is connected.

SLP does a nice job of mounting the EGR into the LS6 manifold. All that is required to adapt the LS1 EGR tube is to cut off the bottom just above the rolled edge of the stock tube. A cutoff wheel was used to modify the tube, and after deburring the edges, the tube is inserted into the brass fitting on the LS6 manifold. The fitting is held snug with a wrench and threaded down until it's finger-tight. Once the nut is snug, it only requires 11/4 turns with a wrench to be properly sealed.

The remaining hardware, including the throttle cable, fuel injector harness connector, air lid, and strut tower bracket, is installed and a final check is made before the battery is connected. The T/A is started, and once it is verified that there are no leaks, the car is shut down and the rear O2 sensors are disabled using HP Tuners' VCM suite. The completed package is very attractive and the car is ready to be strapped onto the chassis dyno to document the power gains.