1998-2002 Pontiac Firebird - STS Subterranean Turbo System Installation - Part 2

Route the harness along the driver side, parallel to the fuel lines, before crossing over the transmission and feeding it into the passenger side of the engine compartment, by the PCM. Route the oil hose alongside the rear wiring harness and into the engine compartment. Use zip ties along the route of the hose and harness, and be careful to make sure they don't interfere with any linkages or are routed too close to sharp or hot objects.

After mounting the pump and wiring harness, get out the STS oil fill cap and take a closer look. The STS cap screws onto the valve cover just like the stock oil fill cap, but has a 90-degree elbow and quick-connect coupler and nipple at one junction and a barbed slip-fit connection for the oil return hose on the other end.

Trim the oil return line to fit properly, and slip the hose onto the barbed end of the slip fit connector. Once complete, connect the hose to the STS oil fill cap.

It's now time to mount the turbo assembly, but first it is helpful to put the air charge pipe (pipe No. 2) over the axle and connect the 211/44x3-inch silicone hose to the pipe that leads to the turbo compressor (pipe No. 1). The 2x3-inch silicone hose that connects pipe No. 1 to the compressor is slipped on but not clamped at this point.

Remove the exhaust tailpipe from the turbo assembly before installing the turbo. Here, Billy May of Texas Rear Turbos lifts up the turbo assembly, putting the turbine inlet pipe over the exhaust pipe and then slips the fresh-air inlet pipe into the factory rubber hanger. He visually gauges how far to move the assembly to the left or right based on how the over-the-axle pipe lines up with the turbo housing. Once satisfied with the preliminary placement, scribe a line at the point where the turbo and exhaust pipe will be joined and...

connect the tailpipe with a V-band clamp and 11/42-inch box-end wrench. Don't completely tighten the exhaust pipe, as the object of positioning it is to be able to clock (rotate upward) the turbo housing as far up into the underside of the car as the tailpipe position allows. Once satisfied with the location of the turbo housing (the housing needs to line up with pipe No. 1 that comes over the axle) and tailpipe orientation, tighten the six each compressor and turbine housing bolts with a 11/42-inch wrench.