GrimmSpeed Chase Overtake Turbo Upgrade Kits for 2018 Subaru WRX STI

CARB Compliance / Exemption Warning: If you live in California and your application for this product is not CARB Compliant / Exempt, then you cannot purchase it for public highway or street use (in that case it could only be used for formally sanctioned race use on a racing vehicle that may never be used on a public highway or street). If your application is not CARB Compliant / Exempt and you're shipping to California, our system will let you know on the final checkout page.

This manufacturer has a policy which prevents shipment to California for applications of this product that are not CARB Compliant / Exempt. Therefore, if you live in California, you will not be able to receive your part if it does not have a CARB EO #, even if it is for a dedicated race vehicle.

These turbos are designed to fit directly on the stock turbo flange. A tune and fuel upgrades are required to properly utilize the increased power levels these turbos offer.

As you slowly build your engine for more power, you find that the stock turbo begins to struggle to keep up. The stock turbo can only handle so much pressure and airflow before it can no longer deliver what is necessary. GrimmSpeed spent 3 years developing these "Chase" JB400 and "Overtake" BB500 turbo upgrades to solve this problem, and the results are amazing.

• The Chase JB400 is the smaller option, but delivers incredible punch. Let's just say it's not your average journal bearing turbo. The compressor wheel size (Inducer / Exducer) is: 51.2mm / 73.8mm Extended tip, 48 Trim, and the turbine wheel size (Inducer / Exducer) is: 53.8mm / 47mm, 76 Trim. Compressor A/R is 0.65 and Turbine A/R is 0.88. The compressor wheel is made of billet 2618 aluminum, and the compressor housing is made of A356 aluminum. The Chase JB400 turbo also uses severe-duty 360 degree thrust and twin hydrodynamic bearings for extreme reliability for it's size. It's got quick response and excellent spool too. The wastegate is also adjustable and preset to 15 PSI.
• The Overtake BB500 is the larger one of the two turbos and brings it's best to the table. In short, it's a world-class ball bearing turbo that still has great response and spool characteristics. The compressor wheel size (Inducer / Exducer) is: 55.1mm / 74.6mm, 54 Trim, and the turbine wheel size (Inducer / Exducer) is: 60mm / 55.1mm, 84 Trim. Compressor A/R is 0.65 and Turbine A/R is 0.88. Made from the same materials as the JB400 but much larger in size. This option also uses upgraded ceramic ball bearing featuring silver plated 4340 steel bearing cages for exceptional strength and durability at very high speeds and heat. The wastegate is also adjustable and preset to 15 PSI.

Key Features:

• Capable of 440+ whp on the Chase JB400 Turbo and 488+ whp on the Overtake BB500 Turbo while still maintaining great throttle response and mid-range power / torque. These results can be achieved with just basic bolt-ons, fuel mods, and a tune. More hardcore upgrades like cams and an intake manifold will yield even more power.
• Made from top-tier materials for extreme durability and performance.
• Fits on the stock turbo flange.
• Incredible flow and operation.
• Adjustable wastegate.
• 3 years of development time to achieve perfection!