RENAULT

A legend of the rally in the details

This is the story of one of the most famous cars of Group B rallys. Not for its sporting history, since it was not one of the most successful in the category, but for the evolution of engineering to create a car that was based on the Renault 5 Street, but that was boosted up to 350 hp, was changed the place of its engine and added an enormous body kit. Today we review the history of the Renault 5 Maxi Turbo.
To know the history of Maxi Turbo it is necessary to go back to 1976, when the French brand decides to put in motion the project that would culminate with the creation of the Renault 5 Turbo, after the Alpine A110 of competition ended its life in racing. Over the years, the R5 Turbo would go through different phases and know several versions that would have in the 5 Maxi Turbo of 1984 its maximum expression.



Before knowing all the details of the R5 Maxi Turbo, it is important to know the family tree of the model, since the Maxi version is the result of a continuous evolution that went through different versions of the 5 Turbo before ending in what was the most powerful and radical version of the model. And for this we have to go back to the second half of the 70s, when the development program of the Renault 5 Turbo, the ‘fat ass’, as it was popularly known, began.



It was based on the original Renault 5, but had received so many changes, the result of a complete development program, that it looked more like a bodybuilder on steroids than with a small and agile R5. However, it retained much of its DNA, combined with much more powerful mechanics that had migrated from the front hood to a new position behind the front seats in the center of the chassis.
The engine had also improved, converting to a supercharged 1.4-liter unit via a Garrett T3 turbo that, according to Renault, allowed it to deliver up to 160 hp of power, with Bosch K Jetronic injection, a five-speed manual transmission and rear-wheel drive. In addition, the scale fixed its weight at 970 kg, which allowed it a huge performance.



Its presentation took place in January 1980 and showed a front part of the Renault 5 Alpine, the steering of the Renault 5 Copa, the rear suspension of the Alpine A310 Gr 4 and the transmission of the R30 TX. In turn, the engine had turned to its new longitudinal central location and this required new solutions for cooling. Renault engineers then opted to equip the 5 Turbo with a new wider body kit, especially at the rear (hence its nickname 'Fat Ass'), where side air intakes were integrated to directly cool the engine. This configuration would be the basis for the Renault 5 Maxi Turbo.
The Renault 5 Turbo had not only been created as the most representative model of the line, but also a first attempt to enhance the company's product portfolio, a goal that Renault achieved by resorting to turbo. The company wanted to participate in Group 4 of the World Rally Championship, which required 400 street units to homologate the competition version.



The official debut of the Renault 5 Turbo Gr 4 was at the Rally de Montecarlo in 1981, a race that the little Frenchman won with Jean Ragnotti at the wheel. The next victory would take until the 1982 Corsican Rally, also with Ragnotti in charge, and, a year later, the Turbo 2 version of the model was born, more powerful and fast. The model gradually became radicalized to the extent that it was surpassed by the effective all-wheel drive machines of Group B, such as the successful Audi quattro.
This new version was named 'Tour de Corse' in honor of the last victory of the first version in Corsica a year earlier. But this version was much more focused on the fast asphalt tracks than on the stretches of snow or dirt, where Renault was clearly outperformed by its all-wheel-drive opponents, so the R5 Turbo 2 continued without winning titles in the World Rally Championship.



In 1984, with 17 victories in the French Rally Championship (5 of which with Ragnotti at the wheel), Renault had only managed to win twice in the World Rally Championship. Group B was at its peak, with cars that were increasingly powerful and fast, and where the French brand was going almost unnoticed by its 'drought' in relation to titles and victories.



That year the Renault 5 Turbo was taken even further to the extreme and a third version was created as Renault's definitive bet to conquer the famous Group B. starting from the base of the R5 Turbo 2 'Tour de Corse', the engine raised its capacity to 1.5 liters thanks to the new cylinders, forged pistons and reinforced crankshaft. A new Bosch mechanical injection system with electronic control was installed and the turbo was replaced by a Garrett T4 / T3 with air/water intercooler. The result of these modifications allowed to raise the power of the new engine developed by Renault Sport up to 350 hp at 6,500 rpm, with a torque that reached up to 420 Nm. These impressive figures were backed by an even lighter weight of only 905 kg (65 kg less than the original R5 Turbo), which gave the Renault 5 Maxi Turbo a weight-to-power ratio of 2.58 kg / hp.

However, Renault continued to bet on a rear-wheel drive configuration, which to date had shown that it was not offering the best results in Group B, dominated by all-wheel drive cars (in fact, the last rear-wheel drive car to win in Group B was the Lancia 037 in 1983). The engine was managed by a semi-automatic 5-speed magnesium transmission.
In the 1984 season, 13 units were assembled, one of them as a prototype, and a year later another 7 copies, which allowed the Renault 5 Maxi Turbo to comply with the requirements of building 20 units for its homologation.
As one would expect, the R5 Maxi Turbo has not won any World Championships either. The only victory he recorded was at the 1985 Corsica Rally, again with Jean Ragnotti and Jean-Marc Andrié in charge.

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