GrimmSpeed CHASE JB400 Turbocharger Kit - Subaru Models (inc. 2002-2014 WRX / 2004-2021 STI)
GrimmSpeed CHASE JB400 Turbocharger Kit - Subaru Models (inc. 2002-2014 WRX / 2004-2021 STI)
GrimmSpeed
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PRODUCT DETAILS
GrimmSpeed CHASE JB400 Turbocharger: Precision Engineering
Explore the GrimmSpeed CHASE JB400 Turbocharger, meticulously designed by Chase Trogan, a senior engineer at GrimmSpeed, after over three years of rigorous testing and development. This turbocharger represents GrimmSpeed's commitment to providing a mid-sized turbocharger that delivers significant power benefits at an attractive price point. Featuring proprietary and state-of-the-art designs for the compressor, turbine, CHRA, and wheel, GrimmSpeed has optimized the physical constraints of the EJ engine bay through extensive flow analysis, failure testing, and thorough road and dyno testing.
Optimal Performance for Stage 3 Cars:
The JB400 is the ideal enhancement for any Stage 3 car, with flow characteristics specifically designed to complement the stock fuel system. The turbocharger's durable severe-duty journal bearing ensures longevity, and even with minor upgrades, it brings a substantial transformation to the power characteristics and delivery of the EJ engine. Quick in response yet delivering a potent punch from mid to top-level RPM range, the JB400 keeps the power consistent between shifts while maintaining a flat power curve.
HIGHLIGHTS:
- Compressor Wheel Size (Inducer / Exducer): 51.2mm / 73.8mm extended tip with a 48 trim
- Turbine Wheel Size (Inducer / Exducer): 53.8mm / 47mm, 76 trim
- Compressor Flow: 49 lb/min
- Compressor Wheel Construction: Billet 2618 alloy
- Compressor Housing Construction: A356 alloy
- Turbine Housing Construction: D5S alloy
- Bearing Type: Journal - Severe duty 360-degree thrust bearing and twin hydrodynamic bearings
- Compressor A/R: 0.65
- Turbine A/R: 0.68
- Very robust and reliable at high boost levels and in race applications
- Dual-piston rings and advanced oil flinger design to combat oil leakage and CHRA pressurization
- Wastegate actuator will come pre-set to 15 psi
- This turbocharger was able to produce 440 WHP and 460 WTQ on GrimmSpeed's Stage 3 2020 STI with tuning and fuel upgrades
- Ideal for daily drivers that demand more power
- Durable enough for track-dedicated race cars
- Will include new gaskets, fluid lines, and hardware for the installation
RallySport Direct proudly carries a great selection of quality performance upgrades by our friends over at GrimmSpeed.
WHY WE CARRY THIS
We only list parts we’d run ourselves or recommend to a friend building a real car. If it feels vague, unverified, or inconsistent, it doesn’t make the cut.
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WHAT TO EXPECT
This is the clean path: correct fitment, clean install, and results that match the intent.
- Install-ready experience with correct mounting where provided
- Finish that holds up to real driving, not just photos
- Selections on this page drive the exact fitment shipped
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Real support
If you have a question, you’ll get a human answer that helps you finish the build — not a copy-paste shrug.
GrimmSpeed CHASE JB400 Turbocharger: Precision Engineering
Explore the GrimmSpeed CHASE JB400 Turbocharger, meticulously designed by Chase Trogan, a senior engineer at GrimmSpeed, after over three years of rigorous testing and development. This turbocharger represents GrimmSpeed's commitment to providing a mid-sized turbocharger that delivers significant power benefits at an attractive price point. Featuring proprietary and state-of-the-art designs for the compressor, turbine, CHRA, and wheel, GrimmSpeed has optimized the physical constraints of the EJ engine bay through extensive flow analysis, failure testing, and thorough road and dyno testing.
Optimal Performance for Stage 3 Cars:
The JB400 is the ideal enhancement for any Stage 3 car, with flow characteristics specifically designed to complement the stock fuel system. The turbocharger's durable severe-duty journal bearing ensures longevity, and even with minor upgrades, it brings a substantial transformation to the power characteristics and delivery of the EJ engine. Quick in response yet delivering a potent punch from mid to top-level RPM range, the JB400 keeps the power consistent between shifts while maintaining a flat power curve.
HIGHLIGHTS:
- Compressor Wheel Size (Inducer / Exducer): 51.2mm / 73.8mm extended tip with a 48 trim
- Turbine Wheel Size (Inducer / Exducer): 53.8mm / 47mm, 76 trim
- Compressor Flow: 49 lb/min
- Compressor Wheel Construction: Billet 2618 alloy
- Compressor Housing Construction: A356 alloy
- Turbine Housing Construction: D5S alloy
- Bearing Type: Journal - Severe duty 360-degree thrust bearing and twin hydrodynamic bearings
- Compressor A/R: 0.65
- Turbine A/R: 0.68
- Very robust and reliable at high boost levels and in race applications
- Dual-piston rings and advanced oil flinger design to combat oil leakage and CHRA pressurization
- Wastegate actuator will come pre-set to 15 psi
- This turbocharger was able to produce 440 WHP and 460 WTQ on GrimmSpeed's Stage 3 2020 STI with tuning and fuel upgrades
- Ideal for daily drivers that demand more power
- Durable enough for track-dedicated race cars
- Will include new gaskets, fluid lines, and hardware for the installation
RallySport Direct proudly carries a great selection of quality performance upgrades by our friends over at GrimmSpeed.
