The Alpha Jag performance lower crank supercharger pulley is designed for Jaguar, Land Rover and Range Rover vehicles equipped with the AJ126 3.0L Supercharged V6 and AJ133 5.0L Supercharged V8 engines.
Manufactured in the USA from high-strength CNC-machined aluminum, this pulley is designed as a lightweight performance upgrade for the factory supercharger drive system. Increasing the effective lower crank pulley diameter drives the supercharger faster, increasing boost potential and improving acceleration when combined with the proper ECU calibration.
Anti-Slip Performance Design
Higher supercharger speed places additional load on the belt drive. The Alpha Jag lower pulley uses an anti-slip belt surface designed to improve belt grip and reduce supercharger belt slip during high-RPM and high-load operation.
The kit includes:
- Alpha Jag lower crank supercharger pulley
- New supercharger belt
- Upgraded metal idler pulley
AJ126 3.0L and AJ133 5.0L Compatibility
Compatible with many supercharged Jaguar, Land Rover and Range Rover applications using the AJ126 3.0L V6 or AJ133 5.0L V8, including compatible:
Jaguar F-Type, XE, XF, XFR, XJ, XJR, XK, XKR, F-Pace, Range Rover and Range Rover Sport / SVR applications.
Because Jaguar used multiple factory crank pulley versions across the AJ126 and AJ133 platforms, we will confirm the correct pulley configuration before shipment. Please provide your factory crank pulley color, along with your year, model and engine. The pulley price does not change based on the factory version. The Alpha Jag pulley is supplied in the red finish shown in the product photos.
ECU Tuning Recommended
A lower supercharger pulley changes supercharger speed, airflow and boost characteristics, so proper ECU tuning is strongly recommended.
When combined with Alpha Jag custom ECU tuning and the appropriate supporting modifications, the lower crank pulley can be used as part of a performance package targeting substantially higher output than stock.
On compatible 5.0L AJ133 applications, properly configured pulley and tuning combinations can support approximately 650–670 hp and higher with other modifications depending on vehicle, fuel, pulley ratio, cooling system and supporting modifications. We currently have the fastest Jaguar F-Type on record doing 10.6 in 1/4th mi and still using stock exhaust.
Results vary by vehicle and setup, so Alpha Jag tuning is tuned using vehicle-specific datalogging rather than relying on a generic calibration.
Works With Additional Alpha Jag Performance Upgrades
This lower crank pulley can be combined with:
- Alpha Jag custom ECU tuning
- Upper supercharger pulley
- Performance intake
- TCU tuning
- Supercharger porting
- Cooling upgrades
Contact Alpha Jag if you are unsure which pulley combination is appropriate for your Jaguar or Range Rover.
