TARGA: motoring.com.au's Renault racer gets flashed

Back from celebrity chef-ferrying duties at the Melbourne F1 Grand Prix, the motoring.com.au Renault Sport Megane tarmac rally car was whisked to Melbourne Performance Centre (MPC) for a Targa-specific tuning session.

To be campaigned in the Showroom category at Targa, only limited options are available to tune the Megane. That means that optimisation, rather than wholesale modification, is the key if you're to go fast within the rules.

RENAULT SPORT AND MPC — TOGETHER AGAIN
Engaging Melbourne Performance Centre for the under-bonnet fettling was a natural choice for Renault Sport and build partners Walkinshaw Performance, as MPC Director Troy Russell explained.

"We have a long-standing relationship with Renault Australia, having built the Megane RS 250s which were used in the 'Red Bull Race Off' at the F1 Grand Prix in 2011 and 2012," said Russell.

"We also built the Meganes used for the Shannons Supercar Showdown reality television series."

In operation for the last 10 years, MPC is perhaps best known for being an Audi Customer Racing 'satellite' team. The Bayswater-based operation is tasked with looking after the mighty R8 LMS race cars seen blitzing Bathurst in the Australian GT Championship.

Beyond that, MPC's objective is simple, says Russell: "Our ultimate idea is to do everything."

With in-house facilities including a composite shop, fabrication section and highly advanced Mainline AWD1500 all-wheel drive dyno, along with a full logistical service, MPC is equipped to carry through on that promise.

"The Targa Showroom rules are very strict, being designed to showcase just what a car such as the Megane can do in near-standard form," explained MPC partner, Lee Burley.

"The restrictions dictate our need to use the standard turbocharger, fuel injectors and fuel pumps. Cooling also needs to be left alone, though from previous experience we know the Megane is pretty good in this area," he explained.

"There are two key areas that we can maximise-- the exhaust and the ECU control. With the exhaust, the rules allow a modest increase in diameter, from the turbocharger back, and the catalytic converter can be removed. We've fabricated a stainless steel cat-bypass pipe (see images) and increased the pipe diameter in key areas to improve flow."

But much of the extra oomph is accessed with clever computer manipulation. MPC reprograms the standard engine control unit to optimise the performance – even on 'normal' 98 RON PULP.

"With the ECU re-flash our aim is to make steady power and torque gains throughout the rev range, to the car more drivable, as well as more powerful," Burley explained.

"We don't want to go overboard here-- adding a lot of boost pressure to make bigger numbers, for example -- because reliability in Showroom specification is paramount.

"To achieve these ends we run the car on the chassis dyno and alter the fuel and ignition maps throughout the rev range. Additionally, with the Megane there is a capability to adjust the electronic 'drive-by-wire' throttle mapping, again to make it more responsive to the driver's inputs in competition conditions."

DANCING ON THE DYNO
Theory lesson over, our visit moved to MPC's dyno room where one of the Team Renault Sport motoring.com.au's Meganes was astride the Mainline's rollers. This all-wheel-drive chassis dyno is an imposing piece of kit, nestled within white walls and a thick, swinging front door to totally enclose the vehicle… And minimise external noise…

With the front door secured and huge cooling fan in place, we were ushered inside. Burley then fired up the Megane, setting both front wheels and the dyno's multi-coloured graphic display spinning simultaneously.

Shackled down, the Megane snorted towards its redline, taking on the demeanour of a caged animal, ready to burst off the rollers and into the workshop. And to think, this was merely a 'baseline' run, to establish current figures before the key modifications were undertaken.

Fast forward and with tuning completed and new exhaust fitted, the Megane was once again spun up on the rollers, and the results were impressive to say the least. Indeed, though we are keeping the actual figures close to our collective chests, the changes clearly demonstrate what can be done within the rules.

The before and after comparison chart shows a clear gap to the latter in both power output and torque. And that increment is maintained from under 2000rpm through to redline.

The 'tuned' power curve shows its greatest gains above 4000rpm, while torque remains above the standard car's peak figure from 2500-5250rpm, with a significantly higher peak and less 'drop off' as revs rise.

Just how these gains will translate into reduced stage times on the Tasmanian tarmac remains to be seen. But after seeing the dyno results we can't wait to find out.

Latest rally news from Targa Tasmania 2013 at motoring.com.au

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