A couple of months ago I saw some guys on the Eurobricks forums trying to build a Lego RC car that can go faster than 40 km/h. Although I don’t have a properly working old Technic RC unit with the remote (somehow I have only faulty ones), I have the necessary amount of buggy motors and 2 BuWizz units, so I had to give this a try 🙂 The whole process turned out to be much-much longer than I expected, but at the end it was a success 🙂
I spent several weeks creating, improving and testing the car. The basic idea was to use 2 BuWizz units, 4 buggy motors and 4 Technic motorcycle wheels and to add only the minimal amount of components to create the lightest and fastest BuWizz powered Lego Technic car. It had to be solid enough to survive all the crashes during the tests and record breaking attempts.
I had several tests at various locations until I found a proper track and the final configuration of the car was created. During this time a lot of parts had to be replaced as the axles were bent after a couple of runs.
The car does not have a conventional steering to reduce weight. For the speed runs only small adjustments are needed, so the direction of the car is controlled by the speed difference of the wheels – there are two control sliders on the phone for each side of the vehicle.
The speed was measured with the on-board GPS unit. The car was controlled mostly with my phone, but for the fastest run I was using an iPad (longer range). Even like this at full power the car ran out of range very quickly.
I think it would be possible to go even faster with this car, but that would require a completely flat surface and a chase vehicle to ensure the controller stays in range. Maybe another time 😉