Hewland’s semi-automatic ‘paddle shift’ system has been developed to complement our existing gearbox range. In recent years, this technology has been used by clients across the world, and has proven to offer a reliable and effective solution at the highest levels of motorsport competition.

Semi-Auto Systems

The system is pneumatically powered, and is supplied with an electrical compressor (12V supply required), while a mechanically driven compressor is available for some applications. A valve block is included, providing a switchable channel of air from the receiver to the gear shift actuators which can be either integrated within the gearbox casing or fitted as a separate ‘bolt-on’ unit. This ensures the benefits of pneumatic shifting can be achieved with most Hewland transmissions. A separate pneumatic throttle actuator (‘blipper’) is used in order to operate the throttle – this is not required when a Fly-By-Wire throttle body is used.

The Gearbox Control Unit (GCU) is the electronic brain behind the whole shift system. It receives shift controls from the two sturdy steering wheel mounted paddles, and together with the pneumatic valves, controls engine cut during a shift and is capable of electronically blipping the throttle (where fly-by-wire throttle is installed). The GCU contains customised software infused with decades of Hewlands shifting knowledge, together with high speed data logging to provide detailed feedback.

High speed CAN communication for data transfer between GCU, Engine ECU and other control/logging hardware is utilised. For low-tech applications it is possible to hard-wire these signals direct to the GCU, where the ECU/CAN isn’t used.

In addition to the paddle switches, the system allows for additional driver operated switches. These additional switches may enable the driver to operate neutral/reverse gear selection, GCU mode selection, and GCU map selection (where applicable).  The GCU also monitors the pressure and temperature of the pneumatic system via integrated sensors within the Valve Block and Accumulator.

Our Semi-Auto system also includes all necessary pneumatic hoses and an in-line filter to ensure perfect fitment and reliability.

To find out more about our Semi-Auto system, please see below:


    1. Improved performance with consistent shifts
    2. Better component life as a result of more accurate shifting
    3. Space saving utilising integrated components
    4. Steering wheel mounted controls ensure better focus on driving
    5. Adaptable, modular design allows Semi-Auto System to be fitted to the majority of Hewland transmission – as both integrated and external solutions
    6. Customised user software is available where teams require access to setup variables such as ratio entry. This will require an additional comms lead.

    Items Included In Kit:
    • Gearbox Control Unit (GCU)
    • Electrically driven compressor
    • Accumulator tank (with AV mounts)
    • Valve block assembly (Standard or High-flow depending on gearbox)
    • Throttle actuator ‘blipper’ (optional)
    • Shift actuator (or pair of actuators integrated into Gearbox)
    • Steering Wheel Paddles (pair)
    • High spec PTFE braided pneumatic hoses with anodised Aluminium or Stainless Steel JIC fittings
    • In-line filter
    • Gear Position, air pressure and air temperature sensors
    • Comprehensive documentation of shift system including parts catalogue and installation, setup, and operation instructions, and table of diagnostic codes
    • Component terminals are available with flying lead or AS connector options
    Additional Items Required:
    • Driver operated switches for shift system control (neutral / detent, map & mode)
    • Electrical wiring between shift system components and engine and data system (i.e. car loom to valves, GPS, pressure & temperature sensors, switches and GCU)
    • Connectors to the GCU (i.e. loom side)
    • Fixtures and linkage to facilitate throttle control
    • 12v relay for compressor switching
    • Comms lead (only required for use with customised user software)
    Clients Include:
    • German DTM
    • Japanese Super GT500
    • Ferrari 458 GT2/3/E
    • Chevron GT3
    • USF2000 Grid
    • BR01 LMP2
    • GTA GT300 Mother Chassis
    • SCG 003
    • Multiple Formula E Teams
    • Components used in Nismo / Mercedes GT3 vehicles

    1. Accessories


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