The Grimmspeed Overtake BB500 Turbo Kit is a stock location, bolt-on turbo for 2004+ Subaru STi and 2002-2014 WRX. The BB500 is a quick spooling, ball bearing turbo able to hit 40 psi before 4100 rpm. Testing delivered 129 HP over a tuned stock STI turbo – even more expected with additional mods!
Just like with the JB400, drivability was the #1 goal and by combining slick aero wheel designs with a dual ceramic ball bearing center housing rotating assembly, the BB500 delivers superior spool results. In testing, this allowed GrimmSpeed to hit 20PSI BEFORE 4100RPM and out-spool the well-performing Chase turbo by an impressive 150 RPM!
When bolted onto the GrimmSpeed 2020 STi Shop Car, they were able to produce 488WHP and 515WTQ. However, the most impressive part is that the Overtake Turbocharger is able to hold 400WTQ+ from 4000RPM and hold over 400WHP from 4250RPM all the way to Redline! With its 55lb compressor wheel and massive 60mm turbine wheel, it allows the engine to really breathe at high RPM.
The design philosophy was to keep the turbo in its powerband after shifts and to hold substantially more power than the stock turbo to redline. The Overtake produces 129 horsepower and 109 ft/lbs of torque over a tuned stock STI turbo. This is all accomplished on a vehicle with only simple bolts-on, cars with additional engine work such as cams, intake manifolds, etc will be able to produce even higher gains!
The Chase JB400 Journal Bearing Turbo is also available.
Vehicle Fitment:
2004-2021 Subaru STi
2002-2014 Subaru WRX *Additional mods required for WRX models
Purchase Includes:
Turbo, gaskets, oil lines, water lines and necessary hardware.
BB500 Quick Specs:
• Compressor Wheel Size (Inducer/Exducer): 55.1mm / 74.6mm, 54 Trim
• Turbine Wheel Size (Inducer/Exducer): 60mm / 55.1mm, 84 Trim
• Compressor Flow: 55lb-min
• Compressor Inlet Diameter: 2.4″
• Compressor Wheel Type Material/Alloy: Billet 2618
• Compressor Housing Alloy: A356
• Turbine Housing Alloy: D5S
• Bearing Type: Ceramic Ball
• Ceramic ball bearing design, featuring silver-plated 4340 bearing cages
• Dual piston rings and advance oil flinger design to combat oil leakage and CHRA pressurization
• Compressor A/R: 0.65
• Turbine A/R: 0.88
• Adjustable Wastegate: Pre-set at 15Psi base pressure
