Darren’s RD400 drag racer

Believe it or not this bike started life as an RD400 Yamaha. The crankcases are original, and the cylinder heads were too until owner Darren machined the fins off (drag racers don’t run for long enough to need cooling).

Darren is a very seasoned drag competitor and he had just rebuilt the bike to be as good as he can make it. It had already done a 9.96 second quarter mile at a terminal 129mph. The world record is around 9.5, so he hopes a custom Zeeltronic ignition will get him a bit closer. It’s got programmable limits for tyre burnout, start line rpm and launch rpm. It can also switch between two ignition maps on the line, with up to ten maps available when connected to a laptop. A big shift light reminds him to change up (it’s a three-speed gearbox), and gear changes happen via an air shifter button on the left bar, again with tunable ignition cut.

With lots of sensors, light and switches Darren wanted a neat loom that could withstand the rigours of racing. So it’s fairly easy to remove and re-fit, and difficult to plug the wrong things together. Darren was very pleased with how tidy it looked.