Throttle controllers are used heavily in the 4x4 industry, but what do they do? In a nutshell, throttle controllers are used to modify the signal from the accelerator pedal to the engine.
By modifying the signal using an algorithm, the throttle controller is able to change the shape of the signal and control the car's speed more precisely. This ability makes the machine much more user friendly in both on and off-road driving. The algorithm changes the signal based on multiple factors including the speed the pedal is depressed, and the angle of depression. This allows for the control of the speed of the vehicle with more accuracy than the native accelerator pedal, allowing the driver to control speed in a more natural manner and preventing unwanted high speed or sudden jerky movements.
How does it work?
The ECU receives input from the accelerator pedal via a cable and a mechanical switch. The signal from the pedal is then converted into an electrical signal by the ECU before being sent to the ignition system. The controller then takes this signal and changes it based on the settings you provide the throttle controller. For example, if you have set the controller to 'fast', it will read 50% pedal and it will tell the ECU that it is 100% pedal. This means that you only have to push the pedal in half way to gain full acceleration. On the other hand, if you are reversing a trailer, or navigating an obstacle offroad, the throttle controller can be set to 'slow' which will have the opposite effect - it will tell the ECU that 50% pedal is only 20% (for example) and will give you much more control over the engine and stop jerky pedal movements.
Does a throttle controller increase engine power? No. Throttle controllers do not have any affect on the power or torque of your vehicle.
Does it work with both manual and automatic gearboxes?
Yes. Except with manual vehicles, 'clutch feathering' is used to replicate what a throttle controller does. This means that it may not be as useful in a manual vehicle. Also if your manual vehicle has rev-matching, throttle controllers have been known to confuse the vehicle and stop the rev matching from working properly. What brands are available? Below are some top brands offering throttle controllers for a wide range of vehicles.
What throttle controller should I get?
Most throttle controllers on the market perform in exactly the same way, so as long as it is a reputable brand there is really no bad choice. Below are some popular and well known brands: