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BMW M Roadster
The Mutha of Z3s
Automobile Magazine
Author: Kitman, Jamie
Spartanburg, South Carolina -- It's murder out there. New, quality sports cars enter the field of mortal combat seemingly every week. So it's a good thing BMW had an M version of its successful Z3 roadster waiting on the bench. Here in BMW's adopted no-nonsense home, the land of the fighting Gamecocks, the language of the gridiron can explain why.
The new M roadster assembled here is another niche BMW that helps to define a market segment -- near supercar. A team player that carries the ball usefully downfield, it offers BMW fans their money's worth, and more, while buying the good ol' boys from Bavaria yet another first down. It also happens to be the fastest BMW ever officially sold in America, if not the best.
In BMW argot, M stands for Motorsport, but to you and me, M stands for More. Twenty-six years of delectable exercises in high performance have come and gone since the first 3.0CSL, and what we've grown to expect from M cars is mostly more power, more handling, and more brakes.
Of course, in line with the industry's growing infatuation with sub-branding and upscale micro-marketing, there are more M variants now than ever before, and BMW will sell more of them than ever, too.
That's one reason M roadsters are built on the assembly line alongside regular production cars. Thankfully, there hasn't been any standard BMW less than mighty fine for a long time. And it's hard to imagine an M edition that's ever really disappointed.
So whaddya know? This one doesn't, either.
What makes a roadster M? Start with the 3.2-liter DOHC 24-valve in-line six out of the M3, developing an identical 240 bhp and 236 pound-feet of torque. Delete the automatic transmission option. Install the M3's mondo brakes (fully vented, 12.4 inches front and 12.3 inches rear) and some jumbo rubber (225/45ZR-17 front, 245/40ZR-17 rear) riding on king-size alloy wheels (17 x 7.5 inches in front, 17 x 9.0 inches at the rear).
Different front and rear aprons, quad exhaust pipes, and chrome side-grille trim distinguish the M roadster further, along with the availability of two exclusive colors (Imola red and evergreen). Inside, color-keyed sport seats and steering wheel, chrome instrument surrounds, and an illuminated shift knob are key emblems of M-ness, as is a standard power roof.
Behind the roadster's new mask and beneath its flamboyant flares lie the M3's variable-assist, variable-ratio power steering and a tweaked suspension. Ride height is dropped an inch, firmed-up dampers are selected, and the front suspension geometry is modified, la M3, with a resized anti-roll bar linked to the struts by way of ball joints. Around back, fortified semi-trailing arms and a reinforced rear crossmember carry the load.
The limited-slip differential seen in the Z3 2.8 remains on duty, but, surprisingly in these litigious times, traction control is not available. According to M brand manager Erik Wensberg, this apparent oversight is because BMW engineers have yet to perfect a system that can deal with the exigencies of the steroidal roadster's compact wheelbase. (But traction control is standard on other Z3 models.)
"Be careful!" Wensberg repeatedly cautioned a passel of lead-foot journalists as we set out on a wet and intermittently freezing morning for a day of M roadster appreciation along a potpourri of potentially deadly hill-country back roads. Patches of snow, ice, and sand; narrow tree-lined passes; and precipitous drop-offs did their part to raise the specter of eternal darkness. The good news was, if we survived, we'd get another chance to meet our maker the following day at the track.
Wensberg's introductory assertion that the M roadster's performance "will rival even the greatest sports car legends such as the AC Cobra" didn't help steady the press corps' nerves. A tail-happy BMW with the ability to rip off 5.5-second rushes to sixty could in theory tread in the Cobra's treacherous footsteps.
But it didn't. We've met the Cobra (well, a pretty convincing replica), and the M is no Cobra. It is seriously rapid, yes. Given the right set of circumstances and a series of erroneous operator inputs (fewer still if you're a real idiot), you could probably even kill yourself in it.
And we all know short wheelbases and gobs of power can be recipes for disaster. But the M roadster is no widow-maker. It wants to go fast; it doesn't want to bite. Lots of grip, as you'd expect from those wide tires, and then it's time for opposite-lock therapy. Under the circumstances, the M roadster rides pretty well, too.
In short, here is a hale and hairy sports car, easily the most exciting of the Z3 variants, with handling that invites -- rather than discourages -- mass exploitation of 240 innocent horsepower.
Still, we can't help feeling the M roadster is something less than the ultimate ultimate driving machine. The previous four-cylinder M3, which did sterling work with a very similar rear suspension layout, always felt more alive. That doesn't mean the M roadster goes to the Hall of Shame. Along with the upcoming M coupe, this diminutive rocket ship carries the ball deep into enemy territory. It's not a supercar, but damn close. Prospective Chevrolet Corvette convertible buyers and Porsche Boxster S intenders may want to think twice.
BMW M ROADSTER
Front-engine, rear-wheel-drive convertible 2-passenger, 2-door steel body
Base price (estimated) $42,000 (+ luxury tax of 7% over $36,000)
ENGINE:
24-valve DOHC 6-in-line, iron block, aluminum head
Bore x stroke 3.40 x 3.53 in (86.4 x 89.6 mm)
Displacement 192 cu in (3152 cc)
Compression ratio 10.5:1
Fuel system sequential multipoint injection
Power SAE net 240 bhp @ 6000 rpm
Torque SAE net 236 lb-ft @ 3800 rpm
Redline 7000 rpm
DRIVETRAIN:
5-speed manual transmission
Gear ratios (I) 4.21 (II) 2.49 (III) 1.66 (IV) 1.24 (V) 1.00 Final-drive ratio 3.23:1
MEASUREMENTS:
Wheelbase 96.8 in
Track front/rear 55.0/58.7 in
Length x width x height 158.5 x 68.5 x 49.8 in
Curb weight 3084 lb
Weight distribution front/rear 51/49%
Coefficient of drag 0.42
Fuel capacity 13.5 gal
Cargo capacity 5.1 cu ft
SUSPENSION:
Independent front, with damper struts, lower control arms, coil springs, anti-roll bar
Independent rear, with dampers, semi-trailing arms, coil springs, anti-roll bar
STEERING:
Rack-and-pinion, variable-ratio, variable-power-assisted
Turns lock to lock 3.2
Turning circle 34.1 ft
BRAKES:
Vented discs front and rear
Anti-lock system
WHEELS AND TIRES:
17 x 7.5-in front, 17 x 9.0-in rear cast aluminum wheels
225/45ZR-17 front, 245/40ZR-17 rear Michelin Pilot SX MXX3 tires
PERFORMANCE (manufacturer's data):
0-60 mph in 5.5 sec
Top speed (electronically limited) 137 mph
Pounds per bhp 12.8
EPA city driving 20 mpg