Car-drawing contest

2y ago


There are many good reasons for building a so-called ‘mid-engined’ supercar, but one of the most compelling is to do with something called ‘polar inertia’. Don’t panic. What this physics teachery expression means is simply ‘resistance to turning’.

As much of the mass as possible is positioned near the middle of the car, because that means it will change direction more willingly. Imagine carrying a ladder horizontally, and trying to turn around. If you hang a pot of paint on each end, it’s quite hard; but if you hang the two pots of paint in the middle, it’s much easier. The weight of the paint pots is still the same, but it’s more centralised. Pots on ends, high polar inertia: pots in middle, low polar inertia. There you go.

This thinking came from racing, of course, where it confers many competitive advantages. Apart from being more lively, the mid-engined layout lends itself to equal front and rear weight distribution. Less weight at the front gives the steering tyres an easier time in the bends, too. A bit more weight towards the back aids traction coming out of them.

As well as putting the weight towards the middle, it makes sense to put it as low down as possible as well. This reduces the tendency for roll in bends, which does more to save tyres and gives the suspension less to cope with. So the driver and passenger sit low down.

'The weight of the paint pots is still the same.'

James Maykesnosense

A dry-sump engine can be mounted a bit lower than a wet-sump one, because, well, there’s less sump to squeeze in. Even using a flat-plane crankshaft can make a small difference. Cross-plane cranks need bigger balancer webs, which makes the crankcase a bit deeper. It all adds up. Or, rather, takes away.

And all of the above helps with aerodynamics, because you can have a car with a low frontal area and a pointy nose – no engine to squeeze in up there.

You know it doesn't make sense any more.

So: the basic shape of the mid-engined supercar is largely dictated by a few facts of physics. This is one of the reasons they appeal. They look the way they do for sound engineering reasons. They just happen to look brilliant as well.

But now what? Electric supercars are upon us, and they don’t have to accommodate an engine or a gearbox or even a fuel tank. The batteries can go in the floor and the (relatively small) electric motors can go in each wheel. Aerodynamics are still a huge consideration, of course, but even they are liberated in this scenario.

Old hat. Seriously.

So for the first time since the Lotus Europa and the Lamborghini Miura, the supercar doesn’t need to look the way it does. The shapes of electric supercars seen so far are a hang-over from the mid-engined philosophy, because that’s how we expect them to look.

The question is; what should they look like? I’ve no real idea. Your sketches, please.

(Pictures are the author's own, which is why they're crap)