Tuners are often praised for being unique, custom-fabricating and building one-off vehicles. While being different can be a good thing, sometimes sticking with what works is simply a better idea. Being a car guy doesn't always necessitate custom-fabbing every single part. Take JSC Speed's project STI for example. Their Sube utilizes a calculated collection of off-the-shelf parts and a stock ECU reflash to make a ton of usable power while still retaining drivability. With the prices on older STIs dropping off as time goes by, they can be picked up for a bargain, even as the MSRP on the new models keeps rising.
JSC purchased this '04 STI at a local dealership for a good price but it was also modified, including parts like a Hydra stand-alone ECU, Power Enterprise 850cc injectors, an 18G turbo and external wastegate setup featuring a TiAL 38mm unit, exhaust, 3" downpipe, Volk rims, and Defi gauges - not bad for a used buy. Unfortunately, it also had its fair share of problems including various exhaust leaks, a blown turbo and a cracked ring land leading to 40psi in cylinder #4. Surprisingly, even with these issues, it drove fine as a daily driver (as long as you don't mind the smoke). Since they knew plans would eventually lead to replacing the engine internals, JSC saddled up the horse most people would have shot behind the barn and got to work.
A plan was devised to do a budget rebuild on the engine, repair the turbocharger, re-weld all of the exhaust piping, and retune the Hydra ECU. The engine was removed, disassembled and sent to R/T Tuning in Landsdale, PA for machining, balancing and a rebuild. JSC chose OEM bearings, CP Pistons and Eagle rods for a solid yet affordable bottom-end. The heads were sent to Slowboy Racing in Indiana, PA for a 5-angle porting and polish, and re-assembly using the stock cams and valvetrain. A few weeks later, the heads and block were reunited, and bolted back together with ARP head studs and Cometic gaskets. With a built motor ready to be reinstalled, they decided to change direction and install a bigger GT35R turbo from Perrin Performance. In stock form, the STI has limited space for a large turbo because the inlet is routed under the intake manifold. The Perrin rotated kit remedies this by turning the turbo 45 degrees and going around the manifold; this allows for large 3" inlet turbos like the GT35R to fit in the STI's engine bay in Garret's native 3" housing for optimal flow. Combined with Perrin's front-mount intercooler and blow-through boost tube, the turbo kit replaces all of the intake piping and the bulk of the exhaust piping, transforming the STI into a monster for just under $5K.
A modified car is nothing more than a collection of parts without a good tune. Knowing this, JSC traveled 150 miles north to New York to visit Automaster in Westchester. Automaster's Rob Bonamici has built and tuned many big-powered Subarus, including a record-setting 630whp stock-ECU STI. After tuning, the STI peaked at an impressive 450 wheel horsepower on Automaster's dyno. But the Hydra, an early unit that came with the car, started acting up shortly after, however, and was eventually replaced with a stock ECU, which Bonamici tuned to an impressive 500 whp; incredible numbers when you consider that a stock STIs pushes about 210whp on the same dyno.