Mitsubishi Galant 4G63 - Power Tuning Part 4

Of more importance, however, is the horsepower curve from 5500 to 7500 rpm, where about 35 hp was realized compared with the stock cams. Even more impressive is the torque level, where the 4G63 was pumping out more than an additional 50 lb-ft when the engine was shut down at 7500 rpm.

Having an engine which makes power down low is usually not analogous with one that makes power up top; there's usually a compromise working. In this case, the 4G63 makes power across the range, which is vitally important for a street car. The cams should continue to pay dividends with the larger turbo, intake manifold, etc. Because of the cams, these components will generate more power. This is a good illustration of parts performing together in the real world.

Next up was the ignition. Having a few choices with Mitsubishi engines, we decided to use a Crane HI6-DI2 set-up. Trying to push this much fuel and air through a turbo engine puts enough demands on the stock ignition. Even with Magnecor 8.5mm plug wires and fresh NGK BPR7ES spark plugs, there comes a time when cylinder pressures demand more.

The Crane system is very modern, complete with weatherpack connections, and an electronic trigger tach adapter. It utilizes a multi-spark system, which sparks up to 12 times per cylinder firing, which cleans up the cylinders slightly by burning all of the fuel present at lower engine speeds. It also delivers a powerful spark in the upper ranges where the engine is under load and at full boost.

Added bonuses include two different rev limiters that adjust with switches and timing retard that's adjustable from 0-20 degrees.

Power increased slightly to a peak of 3 hp and torque 3 lbs-ft of torque, but the smoothness of the engine would lead you to believe otherwise. Installation wasn't difficult and the engine starts faster with the Hi-DI2. Fuel efficiency should increase as well. This is another mod that will pay bigger and bigger benefits as the build-up rolls along.

The 16g turbo was pretty maxed out at the end of the last article. However, it has performed admirably. The 4G63 is ready for more airflow and our Garrett set-up is primed. But they'll have to wait. The turbo will be joined by a sheetmetal intake, upgraded fuel rail and fuel pressure regulator. Also on the coming-soon list are a Nitrous Express single-nozzle nitrous system. The drivetrain will no doubt be calling for attention and we plan to quell it with a Centerforce clutch, Fidenza flywheel and possibly a stronger rear axle assembly from a '91-'94 AWD DSM. Stay tuned to the "Cell."