Playing Rough

European Car

Osh Minelian's spectacular M-powered BMW Z3 roadster made me, a quiet photographer just trying to make a living, feel naughty-real naughty: I did a burn-out in the supermarket parking lot, entered a freeway at triple digits and revved the 3.0-liter motor as I drove by my elderly neighbor walking her cat. The Z3 packing 280 bhp, an RMS Motorsport suspension, big brakes and a tuned exhaust was just too much for me. But I have a feeling I won¹t be the last to behave like a spoiled child while driving such a car

Vic Doolan, president of BMW North America, announced the factory's intentions for the M-powered roadster during the 1996 Monterey Historics. He described plans of placing the same motor that powers the 528i (2.8 liter, 190 bhp inline six) within the Z3's nose. But why, when BMW has much larger engines that will fit, don't they go with something bigger? I¹m sure BMW's main concern is one of safety and, after several hours behind the wheel of Osh's car, they have a legitimate concern. It¹s not that an M-powered Roadster is a bad idea; it's a great idea, but it does make for an incredibly powerful piece of machinery. So for now, BMW has put the brakes on stuffing a great big motor into the Z3; the U.S. market will get the 2.8-liter engine.

As their name implies, Race Marque designs systems for BMWs; systems that increase performance while maintaining the safety and driveability inherent from the factory. This Z3 follows those parameters without exception and, like previous cars, closely follows the Motorsport map.

At the heart of this Z3 lies a 3.0-liter, VANOS-equipped six-cylinder motor, the same engine found in a 1995 M3. While it was indeed powerful and responsive, the M3 was also lauded for its remarkable balance, a balance RMS would need to find within the much lighter 2690-lb. Z3 chassis.

Though the Z3 was more than happy to swallow the new engine, RMS knew beforehand it would need to fabricate components. Soon, the engine was deep within its new home and RMS began upgrading the chassis to M-specs.

Obviously, the brakes were a great place to start, and the Z3 was fitted with binders to match its newfound thrust. The front units and corresponding master cylinder came directly from an E-36 M3. The new brakes feature a floating piston design and the 12.4-in. rotors are vented and slotted for better heat dissipation. The hard lines needed to be modified to fit the larger master cylinder's capacity and the soft lines were swapped for braided stainless-steel cables. The front and rear calipers were also given the RMS appearance group treatment; the calipers have been powder coated in a Motorsport red and the retaining clips have been finished in black chrome.

RMS developed a unique suspension for the MZ3, one that leaves the Roadster equally effective on the street or racetrack. The RMS suspension lowers the MZ3 1.25 in. with RMS's progressive-rate springs and adjustable Koni dampers, while riding on 17-in. Motorsport wheels and 40-series Michelin Pilot rubber (225/45ZR-17). The front struts were slightly modified to accommodate the larger 22mm RMS front sway bar, while the rear bar has been enlarged to 18mm. On their firmest setting, the Koni dampers have more rebound control than a fixed-rate sport damper. On their softest setting, the MZ3 felt smoother than the factory's setup. "The Koni's offer the best of several worlds," claimed Osh. "Dial the externally adjustable knob to its highest position and you're ready to race. Dial it back and the thing rides smooth enough for your grandmother."

RMS was extremely careful in its matching of springs, shocks and sway bars; though performance was a big concern, so was "streetability." The MZ3 would be flogged on a racetrack and then driven home

"RMS has recently completed application development of the Quaife differential onto E-30 and E-36 M3's and we¹ve had really good results," said Osh. "Our goal was to make these cars genuine dual-purpose vehicles; though some suspensions claim to do both, it usually compromises either ride quality or performance."

It all adds up to a moderately sprung car with superior adhesion. While Quaife differentials are extremely effective in distributing torque, their effectiveness is dependent on both tires staying in contact with the road. Even under extreme cornering, the MZ3 kept all four feet firmly planted on the pavement.

The view from the driver's seat is that of the M3 which includes the gauge cluster and the mpg indicator. RMS also included the factory's Modic diagnostic system within electronics. A Motorsport shiftknob is linked to an RMS short shifter which reduces the shift throws 30 percent. It leaves the MZ3 feeling very much like a Formula Ford, though the MZ3's leather-clad cockpit is far more comfortable.

The MZ3's sensuous body line has remained largely intact with the exception of the badging. At the rear, dual tips peek through the lower valance and offer a subtle hint of the car's potential. This RMS dual exhaust is a cat-back system comprised of a larger dual resonator which branches off into 2.25-in. stainless-steel tubing.

The Z3 was under the knife for about three weeks, time enough for RMS to dig through it¹s high-performance handbag and augment the already potent S50/B30 engine. An RMS European airbox provides a bigger intake and output section while an RMS big-bore throttle body gives the 3.0-liter engine more upper-end punch. RMS also replaced the factory's Motronic programming with a more progressive chip. Besides more aggressive fuel and ignition curves, the new chip also extends the rev limiter 300 rpm which allows better use of the MZ3's new found thrust.

This should cost a good chunk of change, but should the Z3 enthusiast (or M3 owner) desire something less costly RMS can provide all the aforementioned components separately

The MZ3 is a magnificent car, a mixture of the Shelby Cobra, Sunbeam Tiger, and TVR all rolled into one irresistibly sexy car. It's dangerously fast, terribly responsive and impossible not to love.