John Simister: Gérard Welter – the man who made the ideas work

That supermini was the Peugeot 205, shaped mostly by him when a Peugeot stylist and not, as is popularly supposed, Pininfarina. The Italian design house had long been a consultant to Peugeot and did indeed shape many of the company's cars, but the case of the 205 it was more a matter of advice and aesthetic adjustments to Welter's main idea. 

And the Le Mans car? That was the WM Peugeot, one of which, driven by Roger Dorchy in the 1988 race, was measured at an astonishing 251mph on the Mulsanne Straight. It was after this feat that l'Automobile Club de l'Ouest, organiser of the 24 Hours, decided the speeds had got out of hand and installed two chicanes on the straight for the 1990 race. They have remained there ever since, although when the straight is in its usual role of public road you're still allowed to go straight ahead. 

The WM Peugeots, their initials standing for Welter and the surname of co-constructor (and Peugeot colleague) Michel Meuneir, were created without any financial support from Peugeot, although the team was able to use some of the technical facilities. Its mission was not to win races but to make an impression. Hence that Mulsanne Straight record, achieved with a lack of drag-inducing downforce which could make the cars scarily skittish in corners.

WM morphed into WR – Welter Racing – in the 1990s, by which time the cars were cornering well enough to occupy the top two grid slots at Le Mans in 1995. Welter himself was becoming sufficiently important to Peugeot's design activities that he became the company's design director in 1998, but the WR team continued to run at Le Mans with entries in the class for smaller prototypes.

I encountered Gérard Welter a few times over the years, at Peugeot design presentations of imminent new models and once, entirely coincidentally, when I was walking along Paris's Champs-Elysée while on a summer holiday. He was instantly recognisable with his metal-rimmed glasses and shock of white, mad-professor hair. But the time I got to meet him properly was in 2006, the year before he retired from Peugeot (but not from running his racing team, which continued with Zytek, rather than Peugeot, engines up to 2010).

Peugeot was staging a press event at the banked Montlhéry circuit, a history-soaked venue on the outskirts of Paris. It was a gathering of the company's motor-show concept cars over the years, all of which we could drive because at that time Peugeot insisted that its concept cars should work. The man who made them do so was an extraordinarily creative – and slightly mad – engineer called Jean-Christophe Bolle-Reddat, who I had previously encountered when I drove his Ferrari 550-like Peugeot 907 concept with a V12 engine made out of two Peugeot V6s joined together. 

This car required its Windows Mobile computer system to reboot every time the car was started, which was a worry when the 907 stalled half-way across a busy Route Nationale with a truck bearing down, but Bolle-Reddat liked living on the edge. Similarly risky, you would think, was letting a photographer and me explore the roads near Charles de Gaulle Airport in the one and only concept prototype of the Peugeot RCZ coupé with nothing more than a promise to bring it back in half an hour. He'd chipped the turbo engine, too, to make it more fun.

Anyway, at Montlhéry there was also present a car rather significant in Peugeot's history, brought there because it set a string of diesel-car records on that circuit in 1965. It was a Peugeot 404 Cabriolet, converted into a streamlined single-seater speed machine with the cockpit enclosed at waistline leve, a bubble canopy for the driver and a 68bhp diesel motor. The bright blue 404 lapped the circuit for 72 hours over 11,627.329km at an average of 100.37mph. 

I had made tentative pre-event arrangements to have a go in the record-breaker for a magazine feature, but bad news awaited me. 'It is not working,' declared Bolle-Reddat, sadly. 'It has a bad water leak.'

Disaster! There was indeed anti-freeze residue all over the engine, and for most car manufacturers it would have ended there. The car would be a static exhibit and that would be that. Not Bolle-Reddat, though. Sensing my dismay, he and his team set about the 404, discovered that the leak was at the gasket between the water pump and the cylinder head, removed the pump, cleaned the mating faces and reassembled with silicone gasket substitute. 

Gérard Welter, as keen as me to drive the 404, then poured water into the radiator using an upturned marker cone as a funnel. The engine was started, water seemed to be staying where it should, and off Welter whooshed for a trial lap of the track last travelled by the Peugeot 41 years previously. 

He returned with a big grin, an under-bonnet check revealed no leaks, and off I went in a car which had demonstrated, a quarter-century before diesels became mainstream, how good a diesel could be in a world yet to worry about particulates.

To drive that remarkably good car was a great honour, but what sticks in my mind is the hands-on enthusiasm of Welter, the design brain, and Bolle-Reddat, the man who made the ideas work, to get it running. I don't think many of today's design directors would have done that.