Electric vehicles are now an important reality and in small steps they are also appearing in the world of offroad competitions. In Germany I met Juergen Fahlbusch who was the first to convert a Unimog 404S to electric and took it to the Europa Truck Trial race.
Photography and story by Paolo Baraldi
The future is knocking on the doors of the world’s offroad racing. I have already witnessed this at the King of the Hammers 2021 where Kyle Seggelin transformed his 1986 Toyota 4Runner into the first electric vehicle to race in the EV class at the Everyman Challenge.
A few weeks ago, I had the opportunity to meet Juergen Fahlbusch in Langenaltheim in Germany during the Europa Truck Trial race, who attended the event with his converted Unimog 404S with electric motor.
What is the electrical retrofit
Electric retrofit refers to the complex of electromechanical modifications made to a traditional vehicle to transform it into an electric vehicle. The purpose of this process is to convert a traditional car with an internal combustion engine into an electric one, ensuring a new and possibly long life.
The kit for converting an old car into an electric one mainly includes: electric motor, battery, wiring and control systems for adapting to the new power supply.
Converting a vehicle into electric is now legal in almost all European countries.
Let's discover the secrets of this first competition truck transformed into electric
Juergen Fahlbusch's truck is a Unimog 404S built in 1965 for the German Bundeswehr with a 130 horsepower 2.8-liter petrol engine, 210 NM torque and a weight of around 2300 kg.
Since 1999 this Unimog has been used for Truck Trial races and since 2010 it is owned by Juergen who since 2011 have used it himself for the Truk Trial.
Juergen Fahlbusch explains how he transformed his Unimog 404S into electric
As I said before, I met Juergen Fahlbusch at the German stage of the Europa Truck Trial, where he very kindly showed me and explained the modifications he made to transform the Unimog 404S into electric.
“After the 2019 season I started the project to convert the truck to an full electric powerd truck.
The engine is replaced by a nominal 25 kw/34 PS asychron three-phase electric motor from Linde Material Handling.
The air cooled engine is based on a standart IEC160 industrial motor with max 6000 rpm; 230NM torque ; 80 kg weight.
The engine is fitted in the normal motor position of the truck. So it is using the old fly-wheel with clutch and gearbox from Mercedes-Benz. Nothing is changed to the normal powertrain".
"As battery I used 160 single cells CAM72 from CALB batteries. The single cell has nominal 3,2V 72AH and 1,9Kg weight. The complete batterypack has nominal 96V 360AH 35KWh 330kg weight.
As microprocessor motor contoller a SuperSigma II from DMC GmbH is used with a maximum possible current of upto 600A".
"All conversion work is done by myself, only for the adapter to the clutch I need professional help by the company Lorey-Maschinenbau (www.lorey-maschinenbau.de) as I don't have a lathe and a CNC milling machine. This company also deliverd the motor; batteries and controller.
The Unimg 404S has normally no power steering. So I converted this normal steering to a electric assisted steering by adding a 12V 1KW electric motor with a worm gear to the steering shaft between the normal steering wheel and the normal Mercedes-Benz steering gear".
"The weight of the converted Unimog 404S is around 2.700Kg and nearly the same as before as I not only take the gasoline-engine out but also all subsystems as watercooling system, 60l tank system, exhaust and 24V lead aiced battery”.
Hours of work and costs for the electrical retrofit of this Unimog 404S
“I didn't exactly mark all the working hours because it was a hobby, I think it's about 300 hours.
The total cost, without labor, of the conversion is € 20,000, of which € 16,000 only for the batteries”.
What real advantages does this electric Unimog offer in the race?
“The advantage is to drive very very slow with good torque and to drive only with one footpedal. Clutch and brake are not used inside the trial sections. Braking is done by the electric motor only".
"With the former gasoline engine a minimum of 2.000 rpm are necessary to drive inside the section. Below the engine had not enough torque. But now mostly I drived with maximum 1.600 rpm limited by electronic speed limiter. I have programmed the system with 4 speed limiters: 800 rpm; 1600 rpm; 2.800 rpm and 6000 rpm.
Change of direction forward and reverse is also done by a switch. The motor can run clockwise and also counterclockwise. So therefore no gearchange is necessary. This is possible as the gear box is an old style with straight thooth”.