Overtake BB500 Turbo Kit

The Grimmspeed Overtake BB500 Turbo Kit is a stock-location, bolt-on turbo upgrade for 2004+ Subaru STi and 2002-2014 WRX models. Engineered with a focus on drivability, it utilizes slick aero wheel designs and a dual ceramic ball bearing center housing rotating assembly to achieve superior spool characteristics. In testing, this turbo was able to hit 20 PSI before 4100 RPM, out-spooling the Chase turbo by 150 RPM. This turbo features a 55lb compressor wheel and a 60mm turbine wheel, allowing the engine to breathe effectively at high RPMs. The design philosophy ensures the turbo stays within its powerband after shifts and maintains substantially more power than the stock turbo through to redline. It is constructed with a billet 2618 compressor wheel and features a ceramic ball bearing design with silver-plated 4340 bearing cages. The CHRA also incorporates dual piston rings and an advanced oil flinger design to combat oil leakage and pressurization. When installed on the GrimmSpeed 2020 STi Shop Car, the Overtake BB500 produced 488 WHP and 515 WTQ. The turbocharger demonstrates impressive performance by holding over 400 WTQ from 4000 RPM and over 400 WHP from 4250 RPM to redline. The kit includes the turbo, gaskets, oil lines, water lines, and necessary hardware. Note that additional modifications are required for WRX models. Key specifications include a compressor wheel size of 55.1mm / 74.6mm (54 Trim), turbine wheel size of 60mm / 55.1mm (84 Trim), and a compressor flow rate of 55 lb/min. The compressor inlet diameter is 2.4 inches, with a compressor A/R of 0.65 and a turbine A/R of 0.88. The wastegate is pre-set at 15 PSI base pressure.