500 Horses

LAMBORGHINI MURCILAGO: 12 ANGRY CYLINDERS

The all-new Lamborghini Murcilago, the latest and greatest ultimate Italian sports car, weighing in at $273,000, eschews turbochargers for 12 cylinders, double-overhead cams, and four valves per cylinder. Why a V12? Lamborghini's Eleanora Negrin points out: "That's what Lamborghinis have."

Ah, tradition. "You can have a more powerful engine with the same displacement if you have more cylinders," Negrin adds. It also helps that the Murcilago displaces 6.2 liters and has a maximum rpm-and reaches its peak power of 575 hp-at 7,500 rpm. Controlling all that might is as challenging as it is exhilarating; Road & Track likened being behind the wheel to standing at a railroad crossing as a freight train passed.

But the Murcilago, which replaces the Diablo for 2003, relies on more than size, multiple cylinders, and four dozen valves. It adds variable valve timing too. Unlike the GT2, the Murcilago adjusts both intake and exhaust camshafts, but to two positions only. The Lamborghini engine also uses a form of atmospheric supercharging to produce maximum peak power without sacrificing a broad torque curve. Lamborghini calls it variable-geometry intake.

Engine designers have long known about the resonance effect in an engine's intake manifold. When the intake valve opens, the air inside is sucked into the cylinder. When the valve closes, air stuck inside the intake tract bounces against the closed valve and rebounds backward. After traveling the length of the tract, it hits the front of the intake manifold and heads toward the intake valve again. A clever engine builder can tune the length of the intake tract to precisely time the arrival of an incoming pulse with the valve opening. This natural supercharging packs slightly more intake air into the cylinder, increasing power.

If engineers were designing the Murcilago only for peak power, short intake tracts-timed for high rpm-would be fine. But the engine would be weak or even stumble at low rpm, with the pulses out of phase. Thus, Lamborghini counters with a butterfly valve that forces the intake through a longer bypass at low engine speeds, much as a trumpet valve changes a trumpet's pitch.

It's this unseen finesse that makes the Murcilago not only the Prince of the Autostrada, but a truly Italian sexy beast.

POWER FOR THE PEOPLE?

More demonstrations of pure power are coming. When the 2003 Mercedes-Benz SL55 hits dealerships later this year, it will combine mechanical supercharging and a 5.5-liter V8 to produce 493 hp. And the Maybach Type 12 sedan, also coming from Mercedes this year, will be powered by a twin-turbo 5.5-liter V12 engine rated at 550 hp and 660 lb.-ft. of torque.

An old racing adage answers the "How fast do you want to go?" question with another: "How much do you have to spend?" What separates the Vipers and Murcilagos from the Miatas and midlevel horsepower homages like the Chrysler 300M is engineering born of breeding and wealth. There's no rational purpose to 500 horses or a 5,700-pound car-except to indulge the wealthy. As they say, money is power.