Posted 18 July, 2025. 200 mph is a magic number in land speed racing. Most vehicles can’t go that fast, and most drivers will never experience 200 mph. Most – if not all – land speed events have special base ball caps that are awarded only to drivers exceeding 200 mph. Loring Timing Association is no exception. Even if I already have 200 mph caps from both Bonneville and Australia, I am very much looking forward to add yet another one to my collection. The next step is 300 mph… 
Although the Green Envy is built for the ultimate goal of 400 mph, 200 mph is an important milestone that we have been chasing for years. The goal of this week was to sort out the throttle issues, the communication problems with the battery management system (BMS), and go 200 mph. We have accomplished all of that now.
The Green Envy has no gearbox; it has a chain drive with a single gear. With the current gearing that is installed, the bike can only do about 205 mph. In simple terms, the permanent magnet AC motor has a maximum RPM that is directly dependent on the battery voltage, and we chose this specific gear ratio to get a top speed of just over 200 mph for this specific event.
With a short track like Loring, gearing becomes very important. Too low and you will reach the max speed before you reach the finishing line. Too tall your acceleration will be too slow and will run out of track before you have reached the top speed. Just as it would happen if you were pedaling a bicycle with only one gear. You will reach the fastest speed with the exact right gearing.
There are indeed tricks you can do with the inverter parameters (“field weakening”) that allow the motor to spin faster than it otherwise would. However, when it spins faster, the horsepower falls off, and the efficiency suffers a bit. So at Bonneville, where you essentially have forever to accelerate, it is best to gear optimally rather than using these tricks.
The next event is planned for September 2025, and for that we will change the gearing and aim for even higher speed. 🙂
P.S. You may have noticed that this website hasn’t been very well updated. There is information that is rather old here, but don’t worry, the Green Envy is still an active project. A major reason for the lack up updates were the major delayed caused by COVID. In addition to that, the website theme I chose appears to have stopped working properly and doesn’t display photos as it should, and I have been uber-busy with my business KiwiFil. All that said, I will try my best to give it an overhaul ASAP.
