We wanted to offer the same components that are equipped on the 2021 ROUSH Stage 3 to our retail supercharger kit customers. The Max Cooling Kit fits your 2018+ ROUSH Supercharged Mustang (Part # 422270) or 2018-2019 ROUSH Stage 3 Mustang. The Max Cooling Kit increases:
- +28% Engine Cooling Capacity
- +22% Supercharger Cooling Capacity
- 14% Reduction in Under Hood Temperatures
Starting in the 2020 model year, each ROUSH Stage 3 Mustang was equipped with our Powertrain Cooling Package. Part of that package was a pair of additional auxiliary coolers that increased the cooling capacity of our Stage 3 Mustang. We are now offering that same auxiliary cooling system for your 2018-2021 ROUSH Supercharged Mustang, as the Max Cooling Kit Upgrade. These components are included in the kit:
- Auxiliary Engine Cooler (Driver Side)
- Auxiliary Supercharger Cooler (Passenger Side)
- (2) Fender Heat Extractors
- (2) Gloss Black Front Fascia Corner Pocket

If you take a look at the 2018-2019 ROUSH Stage 3 compared to the 2020+ ROUSH Stage 3, you’ll notice that the corner pockets on the front fascia are a different design. The 2018-2019 fascia pocket design enhances the styling of the Ford Mustangs’ factory fascia without modifying it. For 2020+, the corner pockets we designed require modification of the front fascia to allow air to pass through them.


(2020 ROUSH Stage 3 shown in the image above)
The auxiliary heat exchangers sit right behind these corner pockets to allow as much air to hit their surfaces to cool your engine and supercharger system. CAD-designed steel brackets are used to mount the coolers behind the fascia for an OE appearance and fitment. Formed hoses are used for the best installation experience and fitment with quick connect fittings. (No relocation of windshield washer bottle is required with this kit)

During vehicle operation, the engine compartment is “pressurized” due to the air entering through all of the front fascia openings. With all of this air entering the engine compartment and nowhere to escape, this results in a lower pressure delta across the auxiliary radiators and low-temp radiator, making it more difficult for air to flow across these heat exchangers. The fender vents allow air to escape from underneath the hood thereby reducing the underhood pressure and allow more airflow across the heat exchangers.

In order for the low-temp radiator and auxiliary heat exchangers to function properly, they require airflow across their surfaces to transfer heat from the low-temp radiator to the air. In general, the greater this airflow, the better the heat transfer. The factory fender liners are also modified during installation to allow airflow through the fender wells instead of being trapped behind the fascia.

We recommend updating to the latest ROUSH Calibration after the Max Cooling Kit has been installed. Integrated into the calibration is our Engine Cool Down Feature. This feature allows you to activate a 3-minute cooldown by holding the brake and pressing the “SET+” button on your steering wheel. This will initiate the fans and force hot air out of the engine compartment to keep your motor and supercharger cool between passes at the track.