Pimp my kart: thyssenkrupp students develop hybrid kart

When students go karting with their tutor, it sounds like a really cool tutor and a lot of fun.

And sometimes the students come back with a really good idea. That’s what happened in a project at the Baden-Württemberg Cooperative State University in Karlsruhe. The creative karters were six of our cooperative education students from thyssenkrupp System Engineering.

Frederik Veith, Maximilian Scholer, Philip Thewes, Marco Klesen, Jakob Wagner and Nils Meyer had had no previous contact with karting. But on their field trips to the kart track, they made a discovery that wouldn’t let go: classic gas karts with IC engines have a big disadvantage against modern electric karts: “Coming out of a bend, gas karts accelerate much more slowly than modern electric karts”, says Maximilian. “Electric motors have a completely different torque curve. Unlike combustion engines, which require a certain engine speed, electric motors give you maximum torque instantly,” says the 24-year-old. Meaning: while gas karts need to tick at higher revs to build torque, electric karts race through the bend at maximum torque even at low revs, making them much faster.

Hybrid upgrade kit for more efficiency – and more karting kicks

And so the idea for their university project was born: to develop a hybrid upgrade kit that could be used to enhance and modernize conventional gas karts. The idea was that hybrid karts could have the best of both worlds: the sound and smell of a conventional engine plus an electric motor to provide support at lower revs. Without further ado the six of them got themselves a used kart and set to work.

“The first question was what type of drive system we should use: hybrid hub motor, axle split, serial hybrid, or parallel hybrid?” says Nils. “But we quickly decided on a parallel structure because it was just the obvious choice for the kart’s continuous drive shaft,” says the 21-year-old. In this setup, both drive units, i.e. the conventional gas engine and the electric motor, can act on the powertrain either alone or in tandem. With this setup, the young engineers were able to achieve an increase in efficiency and, alternatively, a boost function: depending on the program selected, the electric boost can be triggered at the push of a button on the steering wheel or on each acceleration.

Strong support from the university and thyssenkrupp

In altogether more than 1,100 hours of work, Frederik, Maximilian, Philip, Marco, Jakob and Nils did everything themselves: from planning and design to programming and sensor development to building the “AccelErateS+” upgrade kit. The mechanical engineering students sourced the electrical components they needed through the university in Karlsruhe. “Above all finding parts that fit and didn’t bust the budget, that was the biggest challenge,” says Nils. All other components such as machined and sheet metal parts they made themselves – at the production site in Wadern-Lockweller, where vehicle body platforms are manufactured.

“The support we had from thyssenkrupp was huge,” says Maximilian: “They gave us the material and allowed us to use the machines. A lot of apprentices also helped us.” Particularly valuable, he says, was the expert support provided by specialists from thyssenkrupp System Engineering.

40 percent more power

And how much of an improvement in performance was achieved by the young developers? “The gas engine in our used kart makes 4 kW. Our upgrade kit adds another 1.6 kW. That’s a 40 percent increase in power,” says Nils. The acceleration is much better. Driving the kart now is incredible fun!”

The technology is one thing, the economic feasibility of the product another, as Philip stresses: “The project was not only about the design. It was an interconnected project. So for example I was responsible for the marketing and business plan”. Even if the upgrade kit is never intended to go on sale, a proper, albeit fictitious, business plan was developed, based on realistic quantities of kits and assumed production in Germany.

Financially attractive for kart track operators

And lo and behold, in financial terms, too, the hybrid kart would be an attractive proposition for kart track operators. The business plan came up with a notional price of around 2,000 euros for the complete kit including charger. “That’s well below the price of an electric kart, which starts at around 15,000 euros,” says Philip. With a standard gas kart costing 6,000 to 10,000 euros, track operators could pimp their fleets at low cost and offer karting fans a more thrilling ride to boot.

Even more of a pity, then, that the prototype developed as a student project by Frederik, Maximilian, Philip, Marco, Jakob and Nils will never go into production.