1987 Buick GN Turbo V-6 - 10-Second TR

Once the housing is cleaned, Brian is ready to start the turbo assembly. Shown are the ported exhaust housing and the compressor/center section, and the hold-down plate and its bolts.

Cotton drops the center section onto the housing, then secures it with six bolts. To align the turbo correctly, Brian sets an angle finder on the center section and clocks it to 19 degrees before snugging the bolts. These bolts can't be too tight, as the turbo's extreme heat will make them impossible to remove. The inlet housing is clocked to 37 degrees with the compressor housing ring bolts half a turn loose; with the correct angle verified, Brian re-snugs them.

Assembled and ready for action. Cotton's uses Turbonetics turbos due to their excellent reliability, VSR balancing (balanced as a complete rotating assembly), and 1-year warranty. This T-70 compressor will flow up to 84 pounds a minute, with a maximum efficiency of 75 percent. Other options on this hairdryer include a single ball bearing design and a filtered brass fitting for the oil inlet. This turbo will handle close to 700 flywheel horses--more than enough grunt to go 10s. Cotton's offers this CPT70-PBB for $1395.

The turbo is mounted with an SCE gasket and some high-temp silicone. Three nuts are installed over washers, then tightened down. These bolts require re-tightening as well.

Brian tackles several loose ends, including installing the mechanical oil pressure and water temp senders, air/fuel ratio gauge wiring, crank sensor, the heater bypass line, and the turbo feed and return line. In the last installment, the 83-pound injectors had been installed in a factory fuel rail; Jack Cotton had since gotten his hands on one of the first sets of Champion's new high-volume fuel rails and installed them with an Accufab regulator.