Here's Your Twin-Turbo 500-hp BMW M7
After one stab of the loud pedal, you understand why BMW doesn't bother to make an M version of the 7 Series. The 2011 BMW 750Li Alpina B7 is all the M7 you'll ever want, a fire-breathing 500-horsepower version of the BMW 7 Series that doesn't forget that it's all right to be comfortable while you're hurtling down the autobahn at top speed.
Fortunately the 2011 BMW 750Li Alpina B7 isn't restricted to the German autobahn. The Alpina B7 is available through BMW dealers in the U.S. as the successor to the limited-edition 2007-'08 Alpina B7.
The Alpina B7 is actually the fourth generation of Alpina's high-performance version of the full-size BMW sedan. And now that Alpina also has its own design, engineering and test center, the B7 is also the most comprehensively engineered car in that series. Maybe that's why the 2011 BMW 750Li Alpina B7 manages a subtlety that completely belies the car's uniqueness.
Tuner car with tacked-on body kit and loud exhaust this is not.
Luxury, Minimalist Version
Settling into the custom-crafted interior of the 2011 BMW 750Li Alpina B7 is easy, since everything is in the same place as in a BMW 750i, except that it is made out of different stuff. Take the wood trim — myrtle burl, harvested from a tree farm on the Pacific Coast. The instrument gauges are now backlit in Alpina blue, with red needles replacing the standard orange items from BMW. The Alpina logo can be found on the instruments, the steering wheel, the seats and the door sills.
As soon as you take the steering wheel in your hands, you know you're in something special. The rim is finished with silky leather, and BMW's typical cross-stitching has been changed to a directional pattern so your hands aren't rubbed raw when you're spinning the wheel. Alpina has also installed its own proprietary control buttons, notably an aluminum nipple at either side that actuates transmission shifts.
But the most important thing about the steering wheel is that the rim is just the right thickness. You see, some terrible misconception in recent Bavarian history seems to have related the diameter of a steering wheel's rim to the sportiness of the car. Thus, when you order the Sport package of options for your modern BMW, you get a handful of fire hose. Happily, Alpina does away with that nonsense and brings us a steering wheel that is actually more useful as well as more elegant.
The Mr. Hyde Makes Dr. Jekyll Go
Push the ignition button and the car comes to life with a growl that settles into an audible but not intrusive burble. It's the perfect soundtrack for a $126,477 luxury car that happens to have 500 hp.
Our hosts have programmed the navigation system for us and the route reveals long, apparently deserted roads. This would be a problem if we were in, say, some kind of glorified kit car like a Lotus Exige. But since we're at the wheel of a 4,641-pound leviathan with 21-inch wheels, a 4.4-liter V8 and not one but two turbochargers, we're quite happy to learn that the majority of our driving will involve slamming the rightmost pedal to the floor and then holding on.
But before we descend into hooliganism, let us note that this long-wheelbase version of the Alpina B7 (known as the B7 Biturbo in Europe) proves perfectly drivable around town at speeds that are less than supersonic. The engine furnishes us with 516 pound-feet of torque from 3,000-4,750 rpm, which is to say pretty much everywhere. Given the right classical music station, you might remain blissfully unaware of the nature of this beast. The steering is effortless and the ride is actually softer and suppler than that of a conventional 7 Series.
But enough of this. We come to that long, straight road at last, mash the gas pedal, the Alpina-calibrated electronics kick the transmission down two gears and this whole hulking mass of steel is fired down the highway as if from a cannon. Shifts take less than two-hundredths of a second, so there's no coming up for air as the speedometer needle sweeps through the double digits. The rush of torque is addicting enough that it's hard to back off the throttle, but as we crest 130 mph with no sign of a letup under the hood, our survival instinct takes hold and we're going for the brakes.
Now This Is Engineering
Anyone can take a 750i and turn up the boost. The real story here is in the engineering that Alpina has put into its effort. This company has come a long way since 1962 when Burkhard Bovensiepen put dual Weber carburetors on the BMW 1500. Alpina progressed from a motorsports tuner to a full-fledged small-volume manufacturer in 1983, and now it's a full partner with BMW, producing a whole range of specialty cars derived from BMW models. When you buy the 2011 BMW 750Li Alpina B7, it's even backed by a full BMW warranty.
Everywhere you look, this Alpina shows evidence of a comprehensive approach to performance engineering. The floor pan has numerous structural reinforcements. The brakes come from the BMW 760i Protection, BMW's 7,000-pound armored sedan. The usual six-speed ZF-built transmission has been fitted with strengthened gears, including some from ZF's gearbox for 7.5-ton trucks. Even the driveshaft and axles are the beefed-up units from the 760i Protection.
This is heavy-duty engineering that's all about reliability and durability. Many of these cars end up in hot places like Hong Kong or the United Arab Emirates, where they see duty as stoplight racers, so there's a bigger radiator, an oil cooler and three bigger intercoolers, not to mention a rear differential cooler. There are so many coolers here, you'd think a nuclear reactor was locked inside.
It's not all toughness, though. The suspension's coil springs have different rates than the stock 7 Series and the ride height is 0.6 inch lower in front and 0.4 inch in the rear. The latest versions of Alpina's distinctive, 20-spoke turbine-fan wheels now measure 21 inches in diameter and they carry conventional summer performance tires rather than run-flats, 245/35R21s in front and 285/30R21s in the rear. The front spoiler reduces aerodynamic lift by 30 percent and the rear one reduces lift by 57 percent, yet the car has the same coefficient of drag as a stock 750i.
The Engine Is Where the Money Is
The B7's twin-turbo 4.4-liter BMW V8 from the 750i is actually assembled by hand at Alpina's facility in Buchloe, Germany, before being shipped to BMW for installation in this car. The Alpina philosophy is "high torque at low rpm," and as such the 4.4-liter V8 is fitted with special Garrett turbochargers from Honeywell. These lightweight units flow more air and the turbines spool up more quickly, so maximum torque is available as low as 3,000 rpm. Meanwhile, new Mahle pistons afford a lower compression ratio of 9.1:1 in order to withstand 14.7 psi of boost.
The final result is 500 hp at 5,500 rpm and 516 lb-ft of torque at 3,000-4,750 rpm, enough to get this monster to 60 mph from a standstill in 4.5 seconds, BMW says, even though the gas mileage is the same as a stock V12-powered BMW 760i, at 15 mpg city/21 mpg highway.
The engine might be where the money is, but the magic lies in the electronics. When you modify a modern luxury car, you'll need a software engineer, so Alpina started with what is essentially a blank ECU for this car and then designed its own proprietary algorithms. This nets unique mapping for every system you can think of, from the steering and throttle feedback to the suspension and active roll bars. But the coolest feature is dual-stage dynamic traction control. Stage One is BMW stock (wheelspin is regulated immediately), but set the car on Stage Two and it can tell if you're intending to slide. If there's an abrupt change in slip angle (think patch of wet leaves), the DTC will still rein things in, but if the change is progressive, your wildest drift is allowed!
The 2011 BMW 750Li Alpina B7 is an entirely reengineered car — literally from the ground up. If you're looking for a plush take on a would-be BMW M7, there's no other choice, right down to the factory warranty. And we must admit, it is cheaper, faster and more exclusive than a V12-powered BMW 760Li.
You can have your Alpina B7 as a short-wheelbase BMW 750i, priced at $122,875. Once you step up to the long-wheelbase BMW 750Li, then that will be $126,755. (In Europe you can get an all-wheel-drive version.)
You'd think that there would be not so many people looking to drain their wallet so comprehensively to get a juiced-up BMW 7 Series, but Alpina figures there are between 450 and 500 of you. Considering the speed with which the 2007-'08 Alpina B7 went through BMW dealerships, you might want to get in line soon.
Edmunds attended a manufacturer-sponsored event, to which selected members of the press were invited, to facilitate this report.