Driving Jonny Smith's 800bhp Flux Capacitor

Pasted on the transmission tunnel inside Jonny Smith’s Flux Capacitor is a clipping from the 1976 Autocar road test of the Enfield 8000 EV.

It reads: “Naturally, with a kerb weight of just a little under 1 ton and only 8bhp to propel it, the Enfield is no candidate for the drag strips.” Even the safest assumptions can be risky in this business.

On 16 July last year the 800bhp Flux Capacitor, named after the device that powers Dr Emmett Brown’s DeLorean time machine in Back to the Future, became the fastest street-legal electric vehicle in the world, covering Santa Pod Raceway’s quarter mile in 9.86sec with a terminal speed of 121mph.

At 1725mm, the Enfield’s wheelbase is shorter than its owner stands tall, and the car looks like something out of a circus act. If the thought of multiplying the Enfield’s power output of 8bhp by a factor of 100 seems preposterous, that’s because it is. “Everyone said it would be undriveable,” says Smith, “but it has exceeded expectations.”

So why choose such an unlikely candidate? Smith’s idea first formed during a trip to Japan in 2009, where a drive in a prototype Nissan Leaf made an impression. “I made up my mind then to build a hot rod EV but didn’t want to convert a piston engine car,” he continues. “I wanted to do an old EV and found this. I liked it immediately because it was odd, British and unlikely.”

It took a year to track the rare car down and conversion work began in 2012. The 8bhp electric motor and Reliant rear axle were removed. Two 9.0in DC motors, rated at 2000A and producing a combined 800bhp and 1200lb ft, now fit in a cradle mounted inside the Enfield’s transmission tunnel. The axle has been replaced by a specially made Ford unit attached to the body by four trailing links.

There’s no gearbox, drive is direct through a 6.0in propshaft and 400V are supplied by four lithium ion battery packs. Three are mounted under the bonnet and one is in the rear, all assembled from a total of 188 military-grade pouch cells. It is fitting that the same batteries are used to power the Gatling guns in a Bell SuperCobra helicopter, because, in all honesty, the entire machine looks positively lethal.