How to future-proof a classic vehicle

Nicola Brittain

Tired of your classic leaking oil and breaking down? Maybe this is the solution.

How do you future-proof a classic? One way is to electrify it while keeping the chassis, body and original vehicle architecture, so the installation is fully reversible.

This is precisely what Oxfordshire, UK-based company Everrati has done to the vehicle pictured, a Land Rover Series IIa, now residing at its new home in Florida. It’s believed to be the first electrified series Land Rover in North America.

It would be a mistake to view the vehicle as just a conversion. Far too much engineering has taken place. From vehicle acquisition to the completion of testing and handover to client can take anything up to 18 months. The company prefers to use the phrase “restore and redefine.”

Everrati’s Lead Systems Engineer, Jack Bolt explains the procedure: “We apply a full OE-style development process. Firstly, we weigh it. Weight distribution is extremely important. We aim to keep the driving characteristics as close to the original as possible. Next, we remove all of the internal combustion components (engine, gearbox, fuel tank etc), then we 3-D scan everything, with particular attention to the engine bay. Because we are keeping the chassis and components mounts the same, it’s crucial we get the packaging right at this stage.”

Bolt, a veteran of the electric drive systems and vehicle development division at McLaren, was Everrati’s first employee in 2020. He manages all aspects of the electric system. “Once we have everything recorded in SolidWorks, this is when I step in. I start with the customer’s exact requirements - power, torque and range - and this enables me to select components like motors and batteries. In this application we’re looking for an energy-dense cell setup, with the emphasis on range. We’re not chasing out and out performance. With the motors we are not looking to put 500 hp in a series Land Rover that left the factory with 60 hp. We selected a unit with a 160 kW peak, with 500 Newton metres of torque, which together gives us 150 mile range.” Top speed is limited to 70 miles per hour.

Bolt continues, “It’s credit to our design team that the packaging issues can be overcome. It’s a huge challenge to fit everything in while retaining the original chassis, there is lots of back and forth checking and double checking. Fortunately, the vehicles are 10 paces from the design desks, so we can use an iterative process comparing the real thing with the CAD model until we get it right. But it can have its frustrations.”

There are benefits of doing this. It means the original registration plates can be retained, and it can also help with legislation when putting the vehicle back on the road.

Proprietary control system

Although the company utilises industry leading OEM batteries and motors, the power electronics control system required to tie everything together was not available off-the-shelf, so the decision was made to develop a bespoke system in-house. Bolt continues, “The vehicle control unit (VCU) is the lifeblood of all of the systems, including torque delivery, charging control, chassis systems and ancillaries like the HVAC. The underlying control system is the same for any vehicle we build, but is tuned to the unique specification required.”

Integration of existing systems

A large part of getting everything running smoothly is the integration of the existing mechanical systems with the new electronics. For example, the VCU uses a dual potentiometer attached to the accelerator pedal to govern speed. Although this model left the factory with no power steering, for ease-of-use an electronic upgrade has been installed, and a new vacuum pump operates the servo, also controlled by the VCU. It’s all managed according to vehicle speed, drive profile or customer preference. The original drum brakes have been replaced by discs all-round.

Where the transmission is concerned, the original gearbox has been removed and the motor output shaft goes directly into the original transfer box retaining high or low ratio, and the option to select two- or four-wheel-drive.

Regenerative braking is also an option, more for the driving experience rather than as a range extender. This can be tuned by the VCU to be mild or aggressive depending on the tastes of the customer. Drive modes can also be selected by the driver using a switch on the dash to change the level of regen braking and available power.

Bolt says, “We are very lucky with our location, being near an old airfield which we use as proving ground. This has given us the opportunity to fine-tune the regen to get precisely the right amount coming in at the right time. We spent a lot of time in the test and validation process to balance the regen with the mechanical braking and it’s become very predictable, almost to the point that you don’t know it is happening.”

This forms parts of the wider final pre-delivery phase, lasting up to 6 months. Once registered and road legal, many miles are done offsite to complete the testing. Bolt adds, “A big part of our test and validation is systems testing, such as UN REG100.1 for high-voltage safety, as well as UN REG10 electromagnetic compatibility testing. It’s quite a tough process, but we end up with a better product. Everything we learn feeds into the next VCU.”

All this effort does come at a cost. Depending on the final specification, prices can be anything from £170,000 (around USD 214,000) on top of the base vehicle, but it doesn’t seem to be putting customers off. Bolt observes, “People love classic cars because of the way they look, feel and drive. Electrification can bring practical reliability without compromising on the passion and enthusiasm and when you couple this to emissions legislation, such as cities increasingly operating ultra-low emission zones, I see this type of EV market growing. This will only be accelerated by advances in technology, in particular where batteries are concerned.”