EXPERT’S GUIDE TO... ECU ENGINE CONTROL UNIT
You might think it is you in charge of the throttle but it’s clever electronics that are calling the shots
runs Palmer Performance, who build and tune bikes for the track. He is also Crew Chief for racer Danny Buchan, currently second in the Pirelli National Superstock 1000 championship at BSB. www.palmerperformance.co.uk A bike’s brain is called the ECU, or Engine Control Unit. Considering how important it is, it looks very unimpressive – just a box the size of a large phone with wires coming out. ECUS have been around in analogue form since the 1970s and just controlled the basic ignition timing. Later, as technology became digital in the 1980s, ECUS were able to deal with more. Nowadays ECUS use microprocessors that can read all the inputs from a range of sensors – around 20 on the latest bikes – and decide, in milliseconds, how best to control the engine, keeping the air/fuel mixture at a ratio that is safe, while complying with the latest emissions laws and sound restrictions. RPM limit, throttle response and traction control are just a few features it can adjust instantly.
As bikes get more complex, so the ECU has more jobs to deal with. If your bike has different engine modes for wet weather, road riding or track riding, the ECU will have different maps for each mode, changing the engine characteristics, the traction control levels of sensitivity and even leaning ABS. And you thought it was you that was in control…
Once upon a time cornering ABS seemed like witchcraft but it’s all down to a Bosch IMU
Inertial Measurement Unit (IMU) Anti-lock braking system (ABS)