Better than Benz

A former New Zealand motorsport identity is challenging the performance arm of Mercedes-Benz, reports JON ADDISON.

A New Zealander based in the United States is taking on the top European car-tuning establishments with his creation of a Mercedes-Benz-based supercar.

The 1980 New Zealand Grand Prix winner, Steve Millen, whose Stillen group is now the largest performance parts component manufacturer of its type in the United States, has diversified into European-sourced cars with his enhancement of the Mercedes-Benz CLK coupe. Until now, Stillen has concentrated on makeovers of domestic American and Japanese-sourced vehicles.

An idea of the extent of the modifications to the basic Mercedes can be gauged from the price: the standard car costs $US47,900 ($105,800) but Stillen modifications run to $US82,000 ($181,000). By the time a right-hand-drive conversion is added, the Stillen SMK would cost close to $400,000 in New Zealand.

All the design and development of the Stillen SMK was completed in-house, and most of the componentry is built at the company's 7990 sq m headquarters in Costa Mesa, southern California.

The Stillen workforce of 140 is equipped to handle tasks as diverse as computerised design and hand-stitching of Connolly leather upholstery.

The basis of the SMK is the Mercedes-Benz CLK 430 coupe, which is already a potent performer, thanks to an aluminium 4.3-litre V8 engine.

Stillen adds a Vortech supercharger, a water-to-air intercooler, larger fuel injectors and a mandrel-formed stainless steel dual exhaust system. With these modifications, the V8 engine is rated at 375kW at 6000 rpm and 610Nm of torque at 4700 rpm.

Millen had the Stillen team map the engine's performance to create a Jekyll and Hyde character to the SMK. With full supercharger boost coming at the engine's red line, it's almost like the standard car to drive at part-throttle, for example when cruising around town.

But open it up and the SMK clips a second off the standard car's 0-100 km/h time, at 5.2 seconds, and continues to rocket away from it.

Top speed has yet to be proven but the SMK passes the 160 km/h mark in third gear. The Mercedes-Benz five-speed automatic transmission is retained, although Stillen has fitted push-button shifters to the steering wheel to enable the driver to change up or down manually.

Millen says that because maximum supercharger boost doesn't arrive until the red line, drivers don't have to be afraid of using the engine's full rev range.

For those who want the look of the Stillen SMK but not the performance, there's a more mildly tuned version available, with 295kW and 515Nm.

Bringing the performance under control is a completely new braking system, based on huge ventilated discs, with six-piston calipers, for each wheel. Stillen's brake component supplier is AP Racing, which builds brakes for Formula One teams McLaren and Williams.

The Stillen SMK is lowered by 37mm and the front track widened by about 15mm. Stiffer springs and recalibrated Bilstein shock-absorbers give the SMK a firmer feel than the standard car.

Light alloy BBS wheels are fitted with 245/40ZR 18 tyres at the front and 275/35ZR 18 ones at the rear.

The Stillen stylists produced a new look for the Mercedes-Benz that Millen says is "aggressive and muscular, but not gaudy." A significant part of the extra cost goes into achieving the SMK's distinctive appearance. The standard mudguards are cut away by as much as 100mm to accommodate the larger wheels and tyres, and are fitted with flares, which are bonded to the original steel with a special flexible epoxy resin.

The front and rear bumper skins and side sills are all new, manufactured in urethane. Even on the prototype SMK, the new body parts were produced on production moulds, made at Stillen.

Says Millen: "This is a production car - we can build as many as the market demands." In fact, Stillen even matches the original Mercedes-Benz warranty on all the modification componentry.

Inside, the SMK is largely custom-built, with buyers able to specify combinations of colours and patterns in the new Connolly leather upholstery.

While Stillen strips the seats to their frames and rebuilds them with additional bolster and lumbar support, customers can also have the seats contoured to their individual body shapes if they desire.

Completing the interior is the customer's choice of audio and video systems, along with equipment such as GPS navigation systems. Most purchasers are expected to order a Stillen trademark - individual video monitors, built into the rear of each front-seat headrest, for rear-seat occupants. DVD players, on-board telephone and internet connections and Sony PlayStation game sets are also available.

Millen made his name in the United States as the driver who won the most pole positions and most victories in IMSA sports car events, taking the prestigious title in 1992 and 1994. The first Stillen flagship car was based on the Nissan 300ZX sportscar he raced in these events.

Following the end of 300ZX production, Millen went looking for a platform for the company's new flagship, and the CLK soon emerged as a strong contender.

The New Zealand driver had experienced Mercedes-Benz vehicles 10 years previously while doing precision driving for a television commercial, and two years ago drove the racing GTR version of the CLK at Hockenheim, in Germany.

Experience of the CLK 430 on the road, along with a hard look at what the opposition were doing, convinced him to go with the Mercedes-Benz product.

Millen says the established German tuning establishments had left an opening for a sportier, more dynamic interpretation of the car.

Since being taken over by Mercedes-Benz, the AMG product had "softened" in image, while the route taken by rival Brabus carried cost and weight penalties, Millen says. Brabus generally shoehorns larger-capacity Mercedes-Benz engines into its cars to achieve high performance.

Millen says he favours supercharging because it produces the performance when the driver wants it without compromising the balance of the car. It doesn't create the constant internal stresses in the engine that arise from conventional high-compression tuning processes. Also, Stillen is highly experienced in supercharging, offering it on a range of other vehicles such as Chevrolet Suburban sports utilities.

What chances of seeing a Stillen SMK on New Zealand roads? Millen says that, while he'd love to see his flagship in his home country, it's a remote possibility.

"The pricing means its market will always be somewhat limited, although we've exported other high-value vehicles, such as the Suburbans, to Europe and Japan," he said. "We'd certainly be happy to quote on one."