For WRX bolt on turbo applications, Greddy has zeroed in on a T518Z turbo, a fresh unit from Greddy's parent company in Japan. Developted by Mitsubishi the 8cm^2 compressor housing gets maximum thrust from the 18g Wheel. The T518Z features a special flange that matches the odd, triangle-shaped WRX Downpipe.

The unit was bolted on and the WRX was powered up on GT's four-wheel-drive dyno. The Subaru, fitted with a greddy front-mount intercooler kit and evo exhaust system, ran 12 psi of boost. With the stock ECU heading the tuning effort, the WRX laid 238.5 hp and 215.2 lb-ft of torque.

Greddy highly recommends its e-manage tuning computer because the engine can run a tad lean on the topend if boost is pushed past the 12-psi max. Tuning with the e-manage netted 280 plus whp.