If ever there was a pair of natural rivals for the hearts and checkbooks of like-minded enthusiasts, it has to be these two.
What we've got here are a couple of relatively expensive sports cars -- both coupes recently evolved from roadsters, but with large infusions of performance to go with their full-metal tops and revised styling. And both just happen to be made by German companies who take the connection between your steering wheel and those four rubber contact patches very seriously.
Porsche has always specialized in sports cars, of course, while BMW is most famous, outside of the Z-series cars, for its driver-friendly and high-performance 4-seater sedans and coupes. Both, we might add, have also distracted themselves with the production of SUVs (which makes one recall Bobby Darrin in his "folk music" phase), but never mind that for now. We've got real sports cars here.
BMW's new coupe version of the Z4 gets the full M treatment, turned over to that small branch of the company that fiddles with engine and suspension tuning for the sort of driver who
participates in track days-or is unhappy following Fiat Pandas through the Alps. The famously silky dohc inline-6 has been pumped up from the standard Z4's 3.0 liters and respectable 255-bhp output to 3.2 liters and a scintillating 330 bhp. It's the M3's power plant, whose block is made of cast iron rather than aluminum to safely permit a larger bore without lengthening the engine.
The Porsche Cayman S, meanwhile, has been introduced as an entirely new model, filling a gap between the Boxster and 911. It could just as easily have been called the "Boxster Coupe," but that might have suggested it was merely a new body variation, obscuring its larger, more powerful engine. Like the Z4, it takes a 0.2-liter jump -- from 3.2 to 3.4 in this case -- and gains 15 bhp for a total of 295.
Both the BMW and Porsche get big torque gains as well. The Z4's 220 lb.-ft. at 2750 rpm rises to 262 lb.-ft. at 4900 rpm in the M Coupe, and the Boxster's 199 lb.-ft. at 4700 rpm climbs to a very broad and flat (4400-6000 rpm) 251 lb.-ft. in the Cayman.
They are larger, hotter engines, in other words, with a 35-bhp edge going to the M Coupe. But the Porsche is 145 pounds lighter, and there are other mitigating factors, as we shall see.
To compare these two cars under a variety of driving conditions, we motored away from the chaos of our Microsoft Word-haunted offices in Newport Beach, Calif. onto the freeways and up to Willow Springs International Raceway for an entire afternoon of lapping. We then spent another day threading our way along the mountain roads above and behind Los Angeles, around Castaic Lake. We even drove down Spunky Canyon Road.
It doesn't take long on these roads -- or at the track -- to gauge the essentially different characters of these cars.
The BMW is a traditional front-engine sports car with a fairly high cowl and a long view down the hood. You sit low and well back in the cockpit -- although the M Coupe has a perfect 50/50 fore-aft weight distribution, while the mid-engine Porsche (47/53) does not. The whole car exudes a hard mechanical edge, with a succinct 6-speed manual gearbox and a beautiful snarl to the engine as it whoops toward its 8000-rpm redline. Suspension is relatively stiff and the steering is very quick. It can feel a little darty around town, but it slices neatly into sharp curves on a mountain road.
And when you exit those curves, the engine hits hard and drives you down the road with a wallop, particularly on the Sport setting. As on the Porsche, this button remaps the throttle for quicker response. Slightly abrupt in town, it feels great on the back roads. Brakes are superb, with a hard pedal, powerful stopping power and easy modulation.
Overall, the BMW is what used to be called "a man's car." Specials Editor Andrew Bornhop commented that it feels almost like "a German Viper." He added, "It's smaller and more refined than that, but still with that aggressive, powerful nature. I'm also reminded of the Cobra Daytona Coupe."
Step out of the BMW and into the Porsche and suddenly everything seems just a little smoother, more refined and easy. Steering is lighter and more communicative, clutch and shift action more precise, and the suspension soaks up road undulations and bumps as if anticipating them with radar. The engine is very strong, but it delivers power differently from the BMW, accelerating in long, hard surges of speed that can be carried further in every gear. It doesn't have quite the instant power hit of the BMW, but the broad, even torque makes it possible to drive a back road without too much shifting. And when you put your foot in it, the engine note is a marvelous cacophony of intake moan and engine howl.
If the Z4 M Coupe feels long and narrow when you sit in it, the Cayman seems almost square, but aerodynamically rounded off, low and flat as a piece of toast with a wheel at each corner. (Write for party snack recipe.) The cockpit is also more open and airy, with a lower view over the nose and a larger sight picture out the back window. The BMW feels more tunnel-like, its smaller rear window cutting off the tops of cars behind you. You see grilles and headlights, but no drivers.
Both cars have handsome instrument panels and are largely free of cryptic science. The BMW uses handsome wood grain dash and door inserts and clean, simple switches neatly lined up next to rather oddly-shaped instrument bezels for the speedometer and tach. The Porsche also has a nice dash layout, and its three overlapping white-faced gauges are easier to read. The Cayman's seats are also more comfortable -- at least for those of us who crave lumbar adjustment -- but both cars have seats that are supportive at the track.
Both can generate high lateral g's, and we did a lot of laps at the Streets of Willow. And we quickly concluded that the Porsche is easier to drive quickly and smoothly on the track. Both cars are marvelously fast and stable, but the Porsche feels like a low, sophisticated Le Mans car (with the comfort level dialed up and the noise level down) and it circulates the track like a well-mannered electron following a wire. The BMW has a slightly more brutal edge, and likes to be flung and muscled around more. Bornhop came in from the track and said, "I suspect that my heart rate is about 20 beats per minute higher in the BMW than the Porsche. It's exciting and fun, but you definitely have to work harder. The BMW feels like an engine with a chassis, and the Porsche feels like a chassis with an engine.
