GCK RX has officially unveiled its all-new Renault Megane R.S. RX Supercar ahead of the upcoming 2018 FIA World Rallycross Championship season.
The car has been developed from scratch by Prodrive, who originally developed the Mini Countryman RX rallycross car, as well as Subaru’s iconic World Rally cars and Aston Martin’s GT race cars.
Prodrive focussed on three key areas when developing the car; powertrain, suspension, and sub frame, using computer aided design (CAD) and computer aided engineering (CAE) to optimise the car’s production. Safety and performance oriented items on the car were also relentlessly tested using finite element analysis (FEA) and computational fluid dynamics (CFD).
It’s not just the car that is a ground-up development – the engine and gearbox were both specially developed for the car, with Xtrac handling the transmission, and the four-cylinder, two litre turbocharged engine being developed in-house at Prodrive.
Despite being a privateer team’s car – Renault’s minimal involvement centred around minor design tweaks – the car has raised eyebrows throughout the World RX paddock.
The Megane R.S. RX has double wishbone suspension all round – a change from all other World RX cars which have McPherson struts. Prodrive says the decision was made to improve camber and high-speed cornering performance, while also providing a reduction in unsprung mass and mechanical friction, thereby increasing grip. The dampers were another bespoke component for the car, being co-developed by Prodrive and Ohlins.
The brakes are another interesting feature on the car, with the bespoke longitudinal engine allowing Prodrive to fit ‘in-board’ brakes to the car, meaning that instead of the wheel sitting on top of a brake disc, the disc themselves are within the car. To keep the setup compact there’s a brake caliper fixed to the gearbox on the front axle and to the differential on the rear axle. The brake setup keeps the car lighter further, reducing unsprung mass at each corner to less than 30kg.
A big step up from the Mini
Although the new Megane R.S. RX is the second top-level rallycross car to come out of Prodrive’s Banbury headquarters, it is arguably the company’s first true rallycross effort.
The company’s previous car, the Mini Countryman RX, was based on the company’s WRC car that it campaigned between 2011-13, but the Megane R.S. RX was developed entirely from the ground up.
“When we did the Mini RX, since then the cars haven’t changed fundamentally, but the level of optimisation has moved on two or three steps,” said Prodrive’s David Lapworth. “When we did the Mini we felt we could be competitive by basically putting a big engine into a Mini.”
“Since then, while it’s not obvious that the cars have change fundamentally in terms of layout or whatever, it’s obvious that they’ve gone up, particularly with VW coming along,” he said. “Even those coming along with a world rally car are starting with a much better one. So we didn’t think, when we did this car, that we could be competitive by simply doing a better job of converting a World Rally car into a rallycross car.”
During the car’s development, Prodrive felt that they had to develop an all-new car, in order to get ahead of the competition, otherwise they’d be better off waiting for another opportunity.
“When we came to do this one we kind of felt that the best we can do if we do an improved version of a World Rally car is [do] the same as everybody else because they’re already doing a good job of that,” said Lapworth. “We felt it was all or nothing. Either we do a rallycross car, or we wait until the right opportunity comes along.”