Posted by Racer X on 14th Aug 2023
GR Corolla Intercooler Testing
Racer X Intercooler Design Overview
We set out to offer plug-and-play intercooler option that requires no tuning, no cutting, and no permanent modifications to your vehicle when designing the Racer X intercooler for the GR Corolla.
With this goal in mind, we opted for a Garrett core that is larger than OEM, but still fits within the OEM location. The Garrett core that we selected is 0.6" taller and 0.34" thicker than the OEM core. With this increase in heat transfer area, we have seen a drastic drop in charge air temperature using the Racer X intercooler over the OEM intercooler (as shown below in our testing results).
We hate reading useless information and opinions, and we're sure you do too, so we will let our testing data speak for itself (with as little commentary as possible). We've laid out our testing procedure and results below.
Testing Setup
OEM intercooler baseline
(ambient temp 81-82°F)
- Began first dyno pull when oil and coolant temps reached 185°F
- Vehicle turned off and allowed to heat soak for 5 minutes
- Second dyno pull
- Vehicle turned off and allowed to heat soak for 5 minutes
- Third dyno pull
Racer X Intercooler
(ambient temp 84-85°F)
- Allow vehicle to cool down and change over to Racer X intercooler
- Began first dyno pull when oil and coolant temps reached 185°F
- Vehicle turned off and allowed to heat soak for 5 minutes
- Second dyno pull
- Vehicle turned off and allowed to heat soak for 5 minutes
- Third dyno pull
Ambient Temps
OEM Intercooler
Dashed Lines
Run 1 (Red) - 82°F
Run 2 (Green) - 82.5°F
Run 3 (Orange) - 83°F
Racer X Intercooler
Solid Lines
Run 1 (Red) - 84°F
Run 2 (Green) - 85°F
Run 3 (Orange) - 85°F
Click graph to enlarge.
Charge Air Temps
We logged the OEM charge air tempertaure sensor using the Torque Pro software. This is the sensor that is utilized by your ECU to determine air / fuel trims. The charge air temperatures below represent the start and end of each dyno pull for the respective intercooler. The first dyno pull was not performed until the engine reached operating temperature for oil and coolant, as stated above.
OEM Intercooler
Dashed Lines
Run 1 (Red) - Start: 104°F / End: 123.8°F
Run 2 (Green) - Start: 116.8°F / End: 129.2°F
Run 3 (Orange) - Start: 120.2°F / End: 131°F
Racer X Intercooler
Solid Lines
Run 1 (Red) - Start: 93.2°F / End: 104°F
Run 2 (Green) - Start: 109.4°F / End: 111.2°F
Run 3 (Orange) - Start: 113°F / End: 113°F
Click graph to enlarge.
OEM Intercooler - All OEM Runs Overlayed
OEM Intercooler
Dashed Lines
Run 1 (Red)
Max Power: 278.22 HP @ 5600 RPM
Max TQ: 267.09 lb-ft @ 4200 RPM
Run 2 (Green)
Max Power: 273.55 HP @ 5600 RPM
Max TQ: 265.77 lb-ft @ 4200 RPM
Run 3 (Orange)
Max Power: 269.33 HP @ 5600 RPM
Max TQ: 267.16 lb-ft @ 3900 RPM
Click graph to enlarge.
Racer X Intercooler - All Racer X Runs Overlayed
Racer X Intercooler
Solid Lines
Run 1 (Red)
Max Power: 283.19 HP @ 5700 RPM
Max TQ: 275.84 lb-ft @ 3700 RPM
Run 2 (Green)
Max Power: 282.24 HP @ 5400 RPM
Max TQ: 273.81 lb-ft @ 4200 RPM
Run 3 (Orange)
Max Power: 280.16 HP @ 5400 RPM
Max TQ: 276.86 lb-ft @ 4100 RPM
Click graph to enlarge.
All OEM vs Racer X Runs Overlayed
OEM Intercooler
Solid Lines
Max Power: 278.22 HP @ 5600 RPM Run 1 (Red)
Max TQ: 267.16 lb-ft @ 3900 RPM Run 3 (Orange)
Racer X Intercooler
Solid Lines
Max Power: 283.19 HP @ 5700 RPM Run 1 (Red)
Max TQ: 276.86 lb-ft @ 4100 RPM Run 3 (Orange)
Click graph to enlarge.
Run 1 - OEM vs Racer X Intercooler
OEM Intercooler
Dashed Line
Max Power: 278.22 HP @ 5600 RPM
Max TQ: 267.09 lb-ft @ 4200 RPM
Charge air temp start: 104°F
Charge air temp end: 123.8°F
Racer X Intercooler
Solid Line
Max Power: 283.19 HP @ 5700 RPM
Max HP delta over OEM: 13 HP
Max TQ: 275.84 lb-ft @ 3700 RPM
Max TQ delta over OEM: 13 lb-ft
Charge air temp start: 93.2°F
Charge air temp end: 104°F
Click graph to enlarge.
Run 2 - OEM vs Racer X Intercooler
OEM Intercooler
Dashed Line
Max Power: 273.55 HP @ 5600 RPM
Max TQ: 265.77 lb-ft @ 4200 RPM
Charge air temp start: 116.8°F
Charge air temp end: 129.2°F
Racer X Intercooler
Solid Line
Max Power: 282.24 HP @ 5400 RPM
Max HP delta over OEM: 15 HP
Max TQ: 273.81 lb-ft @ 4200 RPM
Max TQ delta over OEM: 11 lb-ft
Charge air temp start: 109.4°F
Charge air temp end: 111.2°F
Click graph to enlarge.
Run 3 - OEM vs Racer X Intercooler
OEM Intercooler
Dashed Line
Max Power: 269.33 HP @ 5600 RPM
Max TQ: 267.16 lb-ft @ 3900 RPM
Charge air temp start: 120.2°F
Charge air temp end: 131°F
Racer X Intercooler
Solid Line
Max Power: 280.16 HP @ 5400 RPM
Max HP delta over OEM: 16 HP
Max TQ: 276.86 lb-ft @ 4100 RPM
Charge air temp start: 113°F
Max TQ delta over OEM: 12 lb-ft
Charge air temp end: 113°F
Click graph to enlarge.
Conclusion
The OEM intercooler had consisent power loss over the three dyno pulls due to heak soak. This is noticable in the starting charge air temps. The starting OEM charge air temp was 10°F higher than the Racer X intercooler while idling to allow the vehicle to reach operating temperature for dyno testing and was 7°F higher between dyno pulls.
The Racer X intercooler had consistent dyno pulls, with each pull being within 1-2 HP of the previous pull. The Racer X intercooler had performance gains of 10-15 HP and 10-15 lb-ft of torque overall. On average, we saw a 20°F reduction in final charge air temps using the Racer X intercooler.