Designing the Backfire
We met to discuss around a big table inside Equipmake’s Norfolk headquarters. The remit was clear: propose an electric car for maximum driving pleasure, broadly obeying the simple, time-honoured Seven rules of simplicity, lightness and small size but with every detail of our new design optimised to meet the challenges of electrification. Why the name? Because a backfire is a reaction to internal combustion in the opposite direction. That seemed appropriate.
Naturally, our proposed car is a two-seater. That format limits its size and bulk, which in turn affects other key stuff, like battery size, brake size and tyre size. And given the wonderful controllability (and slideability) the traditional Seven gets from having rear-wheel drive and locating its driver closer to its rear axle than its front, we decided to opt for that, too. Yates specified that the front-wheel contact patch should be around 75cm ahead of the driver’s feet in the cause of crash safety (we all agreed that the car should meet the relevant modern standards).
The Backfire may have the broad proportions of the Seven, but the requirements of its styling are fairly different. For one thing, it doesn’t need to scoop as much air into a bluff radiator nacelle as the Seven; its much more subtle intakes can be located beneath the car, says Foley. The coming of electrification places more emphasis on sophisticated aerodynamics as a way of preserving range and performance while running the smallest (and therefore lightest) battery practicable, so the Backfire is streamlined and has a small frontal area.
It keeps cycle wings (perhaps more closely wrapped around the wheels than the Seven’s), both for simplicity and as a way of reducing body bulk and weight. We’re looking for zero lift at speed, not downforce, so there are no anti-lift aero bits; they increase drag that cuts range and performance. It’s better to concentrate on making a car with great inherent mechanical grip.
There are no doors: for the Backfire, they’re a needless addition to complexity, weight and cost. The windscreen is simple in design, too. Perhaps not entirely flat, because shaped screens aid cockpit comfort quite a lot and are easier and cheaper to produce for low-volume cars than they were in 1957. But there’s no space or desire for complicated and heavy wind-up windows.