Cars

"Whatever you do, don't touch that," Derek Bell hollers through his helmet, pointing to the very large red button on the dashboard that controls the Halon fire extinguisher. "It takes all the oxygen out of the air and you pass out."

President Bush assured Americans in January's State of the Union address that with his $1.7 billion five-year hydrogen initiative, "America can lead the world in developing clean, hydrogen-powered automobiles." In April, however, while U.S. automakers tinkered with prototypes, Iceland opened the world's first retail hydrogen-fuel pumps in a converted Shell station in Reykjavik.

Transmissions generally get no respect. No one oohs and aahs over a solid clutch plate the way they do for a nice, fat V8. But something's got to connect the engine to the wheels, and without the right transmission, that V8 isn't going anywhere. Accordingly, automakers are putting more into tranny tech than ever before, and the fruits of that investment are beginning to hit the streets, often via the racetrack. Paddle shifting, CVTs, seven-speed transmissions: Here are the latest cars showcasing the modern ways that power connects to pavement.

Fall is going to be a little more interesting this year if you're into cars. By then, Mercedes-Benz will have taken the wraps off its race-bred, carbon-fiber-bodied supercar, the SLR McLaren (left, below). At the same time, those lucky few who plunked down enough simoleons on a deposit for Porsche's race-bred, carbon-fiber-bodied supercar, the Carrera GT (left, above), will start to take delivery of their thoroughbreds. Here's a cheat sheet for the on-the-fence supercar consumer.

Porsche Carrera GT

Engine: 5.7-liter naturally aspirated V10

Enough has been written about BMW's iDrive to fill a 1,000-page driver's manual. Then again, iDrive owners need a 1,000-page manual to figure out how to use it. Credit Audi for succeeding where the vaunted Bavarian firm failed. After a week driving Audi's new 2004 A8, we can report that the carmaker has created an electronic driver-car interface that is genuinely intuitive. The iDrive was just too clever. The menus within menus, the complex haptic-feedback mouse/knob device, and the labyrinth of subsystems all made easy tasks like changing a radio setting far too complex.

It looks like a Fiat Multipla van done in the style of Duchamp's Nude Descending a Staircase. It seats eight people, has eight wheels, and weighs 3-1/4 tons. It's powered by 84 lithium-ion batteries.

In April we got behind the wheel of the Honda FCX, the first fuel cell vehicle to receive U.S. government certification for road use. There was little about our 20-minute test drive that was extraordinary, and that's a compliment: We were impressed that Honda has managed to make a hydrogen-powered car that looks and rides much like the dependable Civic we all know and love.

Troy Irving's 18-year-old Dodge Caravan has a hell of a sound system: 72 amplifiers-you got it, 72-and 36 big 16-volt batteries to put out the 130,000 watts of power needed to rumble his nine 15-inch subwoofers. To put that into perspective, the most powerful production-car audio I know of is the $230,000+ 2003 Aston Martin Vanquish's 1,200-watt system. Irving carries $80,000 worth of audio alone, in a vehicle that is worth, admittedly, slightly less than the Maybach. Must be fun to ride down Main Street with the windows rolled down, right?

It's a Tuesday afternoon at a small, radio control modeler's airport near Los Angeles, and the guy bent over his model Messerschmitt Me-109 looks serious. After a lot of fiddling, he squeezes gasoline into the little piston engine and connects his toolbox-cum-battery pack to the airplane. She's a beauty: deep forest green, meticulous iron crosses on fuselage and wings. "Flies for 16 minutes before

Something about bicycles gets auto manufacturers excited. Maybe it's because they get to show off their engineering chops in a purer medium than the computer-assisted realm of cars. Maybe the marketing department likes a high-ticket accessory it can hawk at dealerships. In any case, bikes from the auto industry tend to fall into one of two categories: those engineered by the car manufacturers themselves and those engineered by bike manufacturers (with the carmaker label slapped on).

I'm about to do a brake job on my daughter's fun-racer, the 1983 911SC Porsche coupe that I spent two years turning from somebody's sorry beater into her loud, slick, tautly sprung street-and-track machine.

In the May 2003 issue, POPULAR SCIENCE showcased several of the groups vying for the X Prize, a $10 million award that will go to the first privately financed team that manages to launch a manned spacecraft to an altitude of 62.5 miles, then repeat the feat within two weeks. X Prize founder Peter Diamandis doesn't expect all of the 24 contenders to produce a finished craft, much less succeed. Their engineering approaches range widely, from runway takeoffs to balloon launches. Here are the plans of a few of the teams that received little or no mention in the original article.

The debut of the worlds first
commercial magnetic levitation rail
system in Shanghai, China, in January
is raising hopes that the United States may finally get onboard.
Urban roadways have never been more congested. A levitating train like Shanghai's, boosters argue, might be just the ticket for short hops between cities or travel between them.

It was all for power. The Tomahawk's designers were so bent on making a brutally powerful motorcycle that they were forced
to mutate most of the bike's components to accommodate the massive V10 Viper engine. Take the gas tank (1A): To shield it from the engine's heat, they had to relocate it to the front fender. Two standard tires couldn't
handle the power, so to keep the 4-wheeler feeling like a bike, designers devised a
unique independent suspension.