Minggu, 01 Agustus 2010

Behind the wheel of Porsche's new hybrid lab

Porsche 911 GT3 R hybrid

Twenty-three hours into the toughest production-car race in the world, the Porsche 911 GT3 R hybrid was leading, more than 30 miles in front of the next car. And then, with an hour to run in the famed Nürburgring 24-hour race, the car failed. Despite the array of breakthrough machinery, the culprit was a simple valve spring.

Now we're driving the exact same car, Porsche's idea of racing into the future. Given that the hybrid came within an hour of winning Germany's premier endurance race, that future is close at hand.

Porsche has combined its favorite racing car, the GT3 R, with a rolling lab of hybrid technology, including a Williams Formula One-derived flywheel kinetic-energy-recovery system and two 60-kilowatt electric motors punching 160 hp more to the front wheels on demand. The rear-drive GT3 R is no slug to begin with, with 480 hp from a 4.0-liter flat-six, a six-speed sequential gearbox, lightweight everything and monster brakes, and it weighs just 2,645 pounds.

We're testing the car on the twisting confines of the Lausitzring near Dresden in northern Germany. Unlike most race cars, it's no small matter of jumping in and appreciating the technology, as the car's race engineer, Owen Hayes explained. “We tried to make it as easy as possible on the drivers, because they are busy enough, but there is still a lot to understand.”

For starters, he ensures us that the carbon and magnetic-powder-composite flywheel isn't going anywhere. It's securely built into an alloy housing that looks as if it could support a coal mine.

We wanted to try the GT3 R hybrid with all the trickery switched off before pulling the trigger on the extra 160 horses. Right off the bat, the car feels different from a normal Porsche. The clutch is heavy and imprecise, the gearshift is brutal and then--once you've pulled second gear hard and fast without lifting off the throttle--you are overwhelmed by a combination of the nuanced engine ripping its delivery through the uninsulated body and the gearbox screaming as the revs rise and fall.

The Lausitzring has an array of tight second-gear corners and a handful of third-gear corners, and the 911 is on a good lap just scraping the 9,000-rpm rev limiter in fifth gear at the end of the straight.

Though the best 911 GT3 RS road cars are known for their precision, the hybrid isn't. Its brake pedal feels different from normal race brakes. The pedal is firm, and the floor-hinged operation feels odd at first. Where you expect a Porsche's brakes to be delicate and precise all the way down near the lockup threshold, this car's goes soggy. You struggle to even pick up when the ABS is operating. That's because the brakes have two jobs: washing off speed and spinning the electric motors so fast, they shoot en-ergy up into the flywheel. Kinetic energy to thermal energy to electrical energy to kinetic energy in the flywheel again.

Another imprecision is turn-in, because that delicate steering response we're used to in rear-engine Porsches is gone. The 2,976-pound car seemed to leave us waiting in slow corners before we could get back on the throttle. Jump on it too early, and the 911 will step out at the back.

It's a wonderful machine, though, lacking only in comparison with the standard GT3 R. It still fills you with a cacophony of sounds from the engine to the gearbox, from the brakes to the tires scrabbling mid-corner. Then it adds smells from hot cool-ant and gearbox oil to tortured brakes. And it's hot inside. The only ventilation is a hole cut into the passenger mirror; its air is ducted down to the flywheel, not the driver. There was a driver fan, but Hayes ordered it out because it was too heavy.

This is one of the kookiest race cars we've driven. You don't worry about charging the system because it does it all on the brakes. It takes a couple of laps to get the wheel whirring at 28,000 rpm, and from there you have juice. It maxes out at 36,000 rpm but can overboost at up to 40,000.

As a driver, you don't worry about it. We just waited until we saw the “Hybrid, Push” board hung out over the pit wall, and we pushed. It's like an invisible hand taking the hurtling 911 and shoving it some more. It makes a fast car faster. It feels as if some weight was taken out of the driveline, because the gasoline engine seems to be picking up its revs faster than before.

When you come to the braking area, in just one sustained push, you get back pretty much all the energy you've just spent. Then you find the second piece of genius about the hybrid. Because it drives the front wheels only, and because each wheel has its own infinitely adjustable electric motor, it's just as useful to control traction out of corners as it is giving more shove down the straights. Nudge the 911's orange nose to the apex, stand on the throttle and—when it starts to step out at the back—tug the little paddle and the electric motors straighten the car instantly and without a trace of torque steer.

That makes it easier to drive, and the drivers admit it's easier on the tires, too. And it's the easiest 911 to drive when it rains. While others are slithering around on the 'Ring's undulating and cambered bends, the hybrid drivers are pulling their paddle and exploding into the distance.

It's also pretty much set and forget once you have the flywheel's rpm up and over its minimum revs. Fully charged, it's good for six to eight seconds of the full 640 hp, but because the flywheel recovers revs every time you brake, it's giving about 20 seconds of boost here, on a 1:25 lap. On the Nürburgring's eight- to nine-minute laps, it's giving a lot more boost than that.

You don't think too much about the system once it's rolling. You just look at the LED lights, and as soon as they climb into the green section, you're free to nail the paddle and the pedal. It's somewhere between 1.3 seconds and two seconds a lap faster with the system here, but that's hardly relevant. The point is that this is Porsche's technology and, if Porsche's history of transferring race technology to the road is any indication, it's coming.




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