RG Motorsport has turned its attention to making the people's car quicker - starting with this 267km/h Golf 6 GTi conversion - yes, that's right, Cyril, 267km/h - at Gauteng altitude.
Better known as a BMW specialist, RGM has been working quietly on the Volkswagen four-cylinder turbo powerplant, using the SA Production Car championship for research and development. RGM-prepared Golf 5 GTi's have won Class T of that series for the past two years and three of top four cars in the class in 2010 carried RGM stickers.
Now a menu of performance upgrades - from mild to wild - for road-going Golf 5 and 6 GTi's is available.
RGM boss Robin Green explained: “Modern tuning techniques are all about careful manipulation of the electronic control systems and this is evident even with showroom models, where we see different outputs from similar engines.
“The latest-generation two-litre FSI engine can cope with much more than the standard 155kW it's rated at in the current Golf 6 GTi - and now we know just how much more!”
Johannesburg car enthusiast Riaan Burger provided his car as the development mule for the project, which started with an uprated KKK K04 turbo; it looks similar from the outside but has very different internals, designed to run cooler and minimise lag.
It breathes in through a free-flow gauze filter and out through a 63mm diameter, stainless-steel exhaust system, shaped and welded in-house and fitted with stainless-steel silencers built to RGM spec. The catalytic convertor has been removed in the interest of performance and the entire system from the turbo onwards is new.
Fuel quantity and air volume are modulated by a Unichip piggybacking on the standard ECU. The engine has been set up with the two maps - one for straight 95 octane and one for a 95/Torco mix (a proven race fuel concentrate).
A switch in the glove compartment optimises the settings for maximum engine performance at increased boost pressure, without risk of detonation. Finally, intake air temperature is lowered by an enlarged intercooler.
And the result?
242kW and 405Nm, corrected to a flywheel rating at sea level - that's 56 percent and 44 percent respectively better than standard.
Getting it all onto the road was the next challenge: a carbon metallic clutch and lightweight flywheel feed torque through the 'box to a Quaife limited-slip differential for optimum traction off the line - and Burger also wisely opted for upgraded front brake pads and discs and braided brake lines.
The RGM-tweaked Golf recorded a best single run of 6.49sec from 0-100 and the average of the two best runs in opposite directions was 6.58sec.
The standing 800m was disposed of in 22 seconds with a terminal velocity on the naughty side of 200km/h.
At first light that morning that conversion had recorded a 267.3km/h top speed run, a 7.3 percent improvement on the 249km/h recorded by a standard Golf 6 GTi, brought along for comparison purposes, only a few minutes earlier.
Green said: “The customer's brief was to create serious horsepower without compromising driveability and we believe that we've achieved that.”
Burger agrees: “The standard Golf 6 GTi is really nice to drive and I didn't want to sacrifice that; I use this car nearly every day.
“But when I'm in a hurry I put my foot down and it accelerates way harder than standard - and if that's still not enough I can flick that switch in the glove compartment… then it's dynamite!”
A Stage 1 Golf 6 GTi upgrade (using the standard turbo) with full stainless-steel exhaust system, high-flow air filter and Unichip delivers 188kW at the flywheel - 33kW more than standard - and costs R13 550, including a six-month or 20 000km warranty.