RENAULT loved turbocharging. From Formula One to the World Rally Championship in the early 1980s if it was a Renault competition car it had a turbo.

The French giant’s obsession with turbocharging saw the technology transferred to its car range as soon as turbos became trendy. The Fuego coupe, its saloon sibling the 18 and the 25 executive express all came with blown engines and most of them were pretty disappointing.

Buyers seduced by Renault’s advertising, who hoped for a taste of Formula One-style excitement, were dismayed when they discovered poor fuelling and dreaded turbo lag.

But there was one Renault Turbo which really did offer competition thrills – if you could afford it.

When Jean Terramorsi, Renault’s vice-president of production, asked Bertone’s Marc Deschamps to design a spiritual successor to the R8 Alpine he laid down one stipulation: that the resulting car should be a genuine competition creation capable of winning rallies.

Management gave Deschamps the go-ahead to use the trendy little 5 supermini as the template for his creation. Naturally, the new car would use a turbocharged engine (in fact, the R5 Turbo would be the first turbocharged Renault to go on sale in 1980) but otherwise the engineers were given a free reign.

And what a team Renault assembled: Gerard Larrousse was a former Le Mans winner, rally driver of note and would go on to head up Renault’s F1 operation before launching his own team, Marcel Tetu was a petrol-head who later worked in Renault’s F1 programme, and Henry Lherm, was responsible for production at the Alpine factory. Engine work was entrusted to Bernard Dudot who juggled his responsibilities with a secret 1.5-litre turbo project that would take Renault into Formula One a few years later. Dudot also designed the all-conquering F1 V10 that dominated the world championship in the 1990s.

Sadly Terramorsi died in 1976 before he saw the fruits of his sporting vision but the skunk works he set up surely did him proud.

The Northern Echo:

The first bodyshell was shipped to the Alpine factory, in Dieppe, in 1977 where it was literally torn apart so the turbo engine could be fitted behind the front seats and ahead of the rear wheels. Yes, the R5 Turbo would be mid-engined just like all the pukka world rally contestants of the time.

But without Terramorsi’s enthusiastic backing the project had to be completed on time and on budget. To that end the front suspension was a development of the same set-up from the 5 Gordini and the rear came from an Alpine A310 sports car (which also donated its ventilated disc brakes). The gearbox was the same as used by the R16.

The engine was a development of the Gordini’s diminutive 1397cc four. FIA motorsport regulations of the time stipulating that blown powerplants had an equivalency of 1.4, meaning the 1397cc was treated the same as a 1956cc normally aspirated powerplant, so the R5 Turbo could sneak into the ‘up-to-2.0-litres’ category.

Simply bolting on a Garret T3 turbo and intercooler stressed the little powerplant too far, however. The team replaced the valves, crankshaft, uprated the oil pump and cylinder head gasket in the search for longevity.

Just 12 months later a working prototype was roaring around a test track in the dead of night and making impressive figures: covering a kilometre from a standing start in 28 seconds and topping out at more than 120mph.

Management were so impressed they directed the team to make the third prototype ready for a competition debut into the Giro d’Italia in the Autumn of 1979. After a stunning public debut at the ’78 Paris Motorshow, where the crowds loved the massive flared wheel arches penned by coachbuilder Heuliez and Renault Style (Bertone having left the project before it was finished), the go-ahead was given to manufacture 400 cars for homologation purposes. In the event, 1,820 cars were built before production switched to the R5 Turbo II in 1983. The second gen car used cheaper parts, the roof, doors and hatch were steel not aluminium, to keep the cost down.

The Northern Echo:

Sadly, the R5 Turbo didn’t have a fairytale race debut. Guy Frequelin set a fastest stage time but his car retired with mechanical problems. It did, however, win the 1981 Monte-Carlo Rally and the 1985 Tour de Corse, with Jean Ragnotti driving. By then, however, rear wheel drive had been outclassed by four-wheel drive and the R5 Turbo was woefully off the pace.

Today Terramorsi’s dream lives on in the turbocharged Clio RS while an original R5 Turbo is an appreciating classic. Not bad for a part-time project designed by a bunch of enthusiasts on a (relative) shoestring.