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

After drilling the hole, tap the hole using a 11/48-inch NPT tap

Clean out the shavings with isopropyl alcohol or brake cleaner. Wrap the fitting on the 45-degree adapter with Teflon tape and screw it into the block-off plate using a 11/42-inch wrench.

Upon reinstallation, ensure the block-off plate-mounting surface is clean and the factory O-ring gasket is in place. Mount the plate upside down, making certain that the 45-degree oil feed line fitting is pointed to the rear of the vehicle. Tighten the two 10mm bolts and then tighten the -4-AN line with a 91/416-inch wrench and route it along the left-hand side of the transmission tunnel to the rear of the car. Mount the stainless braided line to the oil inlet on the turbo-charger's bearing housing or centersection. A check valve ensures oil doesn't enter the housing unless it is pressurized.

The STS-supplied, 12-volt electrical oil pump takes the oil that is pressure-fed to the turbo by the -4 AN line and returns it to the passenger-side valve cover. Before installation, the electric oil pump must be hooked up to a power source and run-in for a minimum of five minutes. Attach jumper wires to the positive and negative connections on the top of the pump body and route them to the car's battery. Don't be alarmed that the pump is noisy during break-in, or that it is broken in dry. Once the electric motor windings break in, the pump will quiet down.

The right-side hose is the feed line from the turbo, while the left-side fitting returns the oil to the engine. Note that there is a pressure switch (protective cover not installed) whose function is to trigger a piezo electric buzzer in the event that oil pressure increases and is not being returned to the engine. Power is provided to the oil pump through the rear wiring harness. The rear harness is supplied power after being connected to the front wiring harness (the installation of which will be covered later). From the rear wiring harness, a yellow wire connects to the negative terminal on the pump, while a black wire carries the power to the positive side. Double check that you have the yellow wire to the negative side, as a pump that runs in reverse will fill the turbine housing with oil and create a smoke show!

After verifying the two wires are installed correctly, slip the protective rubber caps over the switch and top of the pump and mount the assembly to the underbody, directly below the fuel pump harness, using four No. 10 x 1-inch self-tapping screws. Ground the rear wiring harness to the body with a No. 10 self-tapping screw and star washer.