How one enthusiast built the ultimate kit car for £5750

“Building a rear-wheel-drive car is complicated because you need room for the propshaft, so I reckoned that it would be a lot easier to simply use one of the Gordini engines as it was fitted to the Renault: longitudinally-mounted with the gearbox in front. I was able to use all the Renault driveshafts, wishbones and torsion bar springs, plus brakes and hubs.”

Nash spent a long time fiddling with the turbocharger. It sits in front of the engine in the Renault, but he wanted to position the JNS’s radiator in a way that would achieve the low and narrow bodystyle he wanted: “Eventually, I came to the conclusion that having a turbocharger was just asking for a load of trouble, so I junked it and modified the engine with higher-compression pistons to restore the horsepower lost.”

How Nash managed to build such a lovely machine on such a small budget is a combination of doing virtually everything himself and using a lot of lateral thinking when it came to sourcing parts. “Some of the critical welding I farmed out to experts,” he says, “like the rear trailing arms. They’re from a Citroën 2CV, but I needed to shorten them because the rear wheels would have been too far back without doing so. I made all the moulds for the fibreglass body and made the panels, but I got a professional to paint them.”

When I first saw the JNS at Brands, I was sure I was looking at the work of a man with an engineering background as well as some experience of design. “I did an engineering apprenticeship,” explains Nash, “but I ended up doing technical drawings for what was the Central Electricity Generating Board and, before I retired, illustrating operations manuals at Dungeness Power Station.” That explains it, then. As does the beautiful cutaway of the JNS on the garage wall, drawn by its creator.

Driving valuable supercars never bothers me. One-off concept cars are a bit more of a worry, because they cost millions and often years of work to make. But they’re still owned by big car companies. Driving the JNS is much more worrying. I’ve had it insured for £30,000, but it’s not the money; it’s the time it would take Nash to rebuild it if I stuffed it.

So I shall be damned careful. I’m sitting in a wide seat that was once fitted to a Vauxhall Viva. Those white dials came from a Triumph Dolomite (£10); Nash fitted the faces and made the numbers using Letraset. My feet, when they’re not resting on the chequer plate aluminium floor that came from a toilet (£5), press pedals from a Triumph Spitfire.

The now-naturally aspirated Gordini engine breathes through a pair of Weber DCOE carburettors that Nash already owned, but he made the air filters from a sheet of foam and chicken wire. You don’t want to buy expensive K&N filters when you can make some for a few quid. The engine sounds excellent: not loud, with just the right balance of noise from induction and exhaust.