Developing the Ford Focus RS WRC 06 Transmission

Adaptability is an essential trait for teams competing in the dynamic World Rally Championships (WRC) format. Teams must contend in multiple stages, all with drastically differing driving conditions across a challenging variety road surface types and weather conditions. This in itself is a trial of endurance and adaptability for both the vehicle and the team. However, OEMs have the additional challenge of needing to stay one step ahead of the competition in terms of the vehicle specification and being ready to adapt to changes in FIA regulations.

Ricardo engineers have always understood that adaptability and a bespoke approach to engineering challenges are essential to developing championship winning solutions. This is why M-Sport, the UK-based company behind Ford’s challenge for the WRC worked with Ricardo to design and manufacture a new transmission system for the Ford Focus RS WRC 06.

A bespoke rally-ready transmission

The new vehicle required a transmission system which would suit the new package space, meet regulatory requirements, and ensure maximum performance and durability when competing across challenging terrain at high speeds.

Building on our recent success with the Audi R8, the Mitsubishi Pajero Evolution, and our LMP2 products, Ricardo engineers worked with M-Sport to specify a transverse 5-speed gearbox, plus reverse with associated differential for front drive and axle supplying the rear wheels.

The driveline featured an active centre differential to manage the power split between the front and rear axles. It also allowed the rear axle drive to totally disconnect to be able to support hairpin turns with the characteristic rally slides without causing excessive strain on the transmission.

An effective set-up is essential for a vehicle competing in WRC to be adaptable to the different road conditions throughout the rally. Making these adjustments generally happen between stages, but it can sometimes be necessary to make these changes out on the track. To support this,  externally adjustable preload which would enable both the drivers and the mechanics to be able to alter the turn-in and turn-out slip allowances across the axle.

The ability to be able to make quick and effective repairs and adjustments out on the track is essential in a WRC setting. These vehicles are put through their paces under extreme conditions and there is always a risk that a component will become damaged out on the track. The clutch was particularly vulnerable to this. Because these vehicles did not feature a torque limiter, the inevitable torque spikes associated with rock strikes and landing jumps would often lead to clutch damage. To counter this issue, Ricardo and M-Sport deployed an externally mounted clutch to enable the servicing or exchanging of this critical component as quickly and efficiently as possible.

A bespoke solution was developed for the integration of the driveline into the chassis which ensured that vehicle performance was not compromised. This included a two-stage final drive in the rear axle which accommodated both the fuel tank and exhaust, whilst keeping the centre of gravity as low as feasibly possible for optimal handling.

The hydraulic system was deployed to actuate the gearshift and to control the centre differential. This supported the quick power shifts which are vital to achieving optimum stage times and high-speed performance out on the track.

Double title wins for the Ford​ Focus RS WRC 06

After making its debut in the last round of the 2005 season in Australia, Marcus Gronholm and Timo Rautiainen secured a key victory in the Ford Focus RS WRC 06 in the first stage of the 2006 championships in Monte Carlo. It was the Finnish pair’s debut race for Ford World Rally Team and M-Sport.

In the hands of Gronholm and Rautiainen and fellow Finnish drivers, Hirvonen and Lehtinen, the Focus RS WRC 06 took eight wins in the 2006 season. M-Sport also secured Ford’s first manufacturer’s title since 1979, taking the championship by an impressive 29 points. This success would be repeated the following year, with the Ford World Rally team taking a second manufacturer’s title.

Further iterations of the vehicle using Ricardo’s transmission technology would continue to enjoy success until 2010 when another change in regulations meant that the car in its current form had to be retired from competition.

Rob Simmonds, Programme Manager on the Ford Focus programme, looks back on the development of the transmission for the Focus WRC 06:

“Working with the team at M-Sport was a great pleasure and I look back on this time of development with fond memories. Many of the working relationships we built during this time are still as strong today as they were then, and I am pleased to say that I was lucky enough to get the opportunity to work with the M-Sport more recently on their impressive Ford Fiesta WRC.”

Martin Starkey, Managing Director for Ricardo’s Performance Products segment added:
“Over the years, Ricardo has worked with M-Sport on a number of different platforms. We are very pleased to have been part of the great success this team has generated over the years, particularly with the Ford brand in off circuit racing.”

Join us for next month’s instalment of our series celebrating 50 years in the motorsport industry for Ricardo. We will be continuing our theme of adaptability as we reflect on the challenges of bringing diesel to Le Mans.