How the Chrysler ME Four-Twelve Works
The unveiling of the Chrysler ME Four-Twelve concept car at the 2004 North American International Auto Show in Detroit left some auto-industry observers scratching their heads.
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Usually, it's the prestigious European carmakers that craft ultra-expensive, insanely fast supercars, not American companies known more for unpretentious "grocery-getters" than quad-turbo, carbon-fiber land bullets. But the ME Four-Twelve represents a melding of Chrysler's "minivan" ideology with Daimler-Benz's European, performance-centric attitude. The companies are now one and the same, after all, in the form of DaimlerChrysler.
In this article, we'll learn why Chrysler designed a supercar, what the ME Four-Twelve packs under the hood and just what this thoroughbred is capable of.
Concept to Production
A lot can be learned
about this car by asking one very basic question: What in
the world does the name mean? Although not very inspiring,
the name ME Four-Twelve is certainly enlightening: It
stands for the placement of the engine, which is just behind
the driver (Mid-Engine), and the size of the
engine (Four turbochargers
on a Twelve-cylinder engine).
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The ME Four-Twelve falls into a rare class of cars known as supercars -- cars designed to perform like high-performance race cars, with lightweight chassis, vast amounts of horsepower, and nimble handling. It goes without saying that a supercar costs a lot. If the ME were to go into production, it is estimated that it would cost about $150,000.
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The ME started as an idea in the head of DaimlerChrysler chief operating officer Wolfgang Bernhard. Most concept cars are just flashy showroom statements about what the automaker can do. The fact that Bernhard's vision (a production prototype supercar on a par with the best Europe has to offer) put rubber to road about a year after he gave the directive is one of the most amazing things about this car.
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What makes it different from typical concept cars? Chrysler designed the ME Four-Twelve from the beginning to be a realistic (albeit expensive) production model. It meets U.S. government safety regulations. The car is intended to reach its performance benchmarks on fuel you can buy at the corner gas station, not ultra-high-octane racing fuel. The interior is not only customized with climate control, a great audio system, and all the other comforts you'd expect, but it was designed with enough headroom and legroom to fit normal-sized people.
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First and foremost, though, the ME Four-Twelve was designed to go really fast.
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Mid-Engine Designs Rule An overwhelming majority of the top-performing cars in the world feature a mid-engine design. This is a design in which the engine lies in between the front and rear axles, usually just behind the passenger compartment.
Why is the mid-engine design so popular? The engine
is the heaviest part of the car. Putting it the middle
creates a more equal distribution of weight between the
front and rear. This results in better handling overall,
though the learning curve can be tricky for those
accustomed to driving front-engine
cars. |
The ME Engine
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Like most high-performance cars, the ME was built around the engine. The designers started with a twin-turbo V-12 AMG engine, and then put it on steroids. Adding two more turbochargers to the 6.0-liter aluminum power plant cranks the air pressure being pumped into the cylinders to 20 psi.
The electronic, sequential, multipoint fuel-injection system measures the exact amount of fuel needed for each cylinder. A dry-sump oil system helps keep the center of gravity low (and allows the ME to keep its supercar-requisite low profile) and improves performance. With a 9:1 compression rate, the ME operates properly on premium-unleaded gas. Higher compression rates, like the 12:1 ratio typical of race cars and other supercars, generate more horsepower, but they require very high-octane racing fuel.
All those high-tech parts give the car an impressive 850 hp at 5,750 rpm -- close to the 1,000 hp available in the record-setting Bugatti Veyron. Since the car weighs under 3,000 pounds (1,361 kg), the ME's power-to-weight ratio is .295 hp per pound of weight (or 3.4 lbs/hp). It cranks out 850 lb-ft of torque between 2,500 and 4,500 rpm. Each liter of displacement produces a maximum of 142 hp. Every one of those numbers is an eye-opener, even when compared to other supercars.
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Power-to-Weight The power-to-weight ratio of a car is simply the total power output divided by the weight (usually the curb weight -- the weight with no passengers or cargo). The result will be a fraction of a horsepower per pound of car. Here are some famous high-performance cars and their power-to-weight ratios.* How does the ME stack up?
*Stats
calculated from info at
http://www.supercarstats.com.
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The ME Transmission
A transmission specially
designed by Ricardo is getting the power to the rear
wheels.
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The 7-speed, double wet-clutch transmission is controlled with electronic thumb shifters mounted on the steering wheel, just like a Formula One car. In-car computers not only assist with shifting (generating 200-millisecond shift times), but they actually predict which gear will be needed next.
After your amazement wears off, you might find yourself wondering what exactly a double wet-clutch transmission is. A wet clutch is simply a clutch immersed in a lubricating fluid, which keeps the clutch surfaces clean and reduces temperatures. This improves performance and prolongs the life of the clutch.
A double clutch allows for seamless shifting between gears. In a normal manual transmission, the clutch disengages, breaking the connection between the engine and the transmission for a moment, whenever the driver shifts gears. This results in a loss of torque and momentum. In a double clutch, there are two clutches -- one for the even gears and one for the odd gears -- nested within each other. If you're in third gear and make the shift to fourth, the clutch for fourth gear engages at the exact moment that the clutch for third gear pulls away.
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Fancy equipment is great, but what can the ME do with it? The car hasn't been tested independently, so the only performance stats come from Chrysler, based on computer modeling and its own testing. Chrysler reports:
That's what car lovers call, "Putting you back in your seat." The ME should be able to blast down a quarter-mile drag strip in 10.6 seconds at 142 mph.
The ME Suspension
With all that speed, it
takes a well-engineered suspension for a supercar to handle
the corners. The ME Four-Twelve sports a double-wishbone
suspension in the rear, aluminum control arms in the front and
horizontally opposed coil-over dampers with electronically
controlled compression and rebound tuning. That means the
driver can adjust the shocks for different driving
conditions with the push of a button. A blade-type anti-roll
bar keeps the chassis from rolling during turns. This is
adjustable, too. The "blades" are flat, metal pieces
that connect the anti-roll bar to the suspension. Imagine a
plastic ruler lying flat -- it's very flexible. Now imagine
trying to bend it sideways. By turning the blades, it is
possible to adjust for a softer or harder anti-roll bar.
We haven't even mentioned the two most important parts of any car's suspension yet -- where the car meets the driver's hands, and where the car touches the road. At one end is a power-assisted, rack-and-pinion steering system with 2.4 lock-to-lock turns in the steering wheel, and a 36-foot (11-meter) turning radius. That makes for some very responsive handling. At the other end is a set of Michelin high-performance radial tires: 265/35ZR19 in the front and 335/30ZR20 in the rear, mounted on cast aluminum wheels.
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While the engine handles going from 0-100 mph, getting from 100 mph back down to zero is handled by 15.0-inch ventilated carbon, ceramic-composite disc-brake rotors with six-piston aluminum mono-block calipers. The anti-lock brake system can be adjusted by the driver to different profiles, depending on the situation. There are three race settings, plus settings for highway and street driving.
Now let's take a look at how the frame composition and shape of the ME contributes to its performance.
Supercar Frame and Shape
The ME Four-Twelve
looks as fast as it is. Its shape is similar to many supercars
because the mid-engine design and aerodynamic necessities of
going over 200 mph tend to force cars into an "ideal"
high-performance configuration.
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The engine is mounted to a chrome-moly frame, a steel alloy made of chromium and molybdenum originally developed for use in high-temperature environments within power plants. This sub-frame is attached to the main chassis, a monocoque tub made of a carbon fiber and aluminum honeycomb. Monocoque is French for "single shell," and means that the chassis is built from a single "tub" with no internal support framing. The structural strength comes entirely from the shell itself. This tub is combined with carbon-fiber bodywork to give the ME Four-Twelve its shape. Aluminum crush zones make the car safer in the event of an impact. This structure not only looks like something from the year 3030, it is also very light and rigid -- very desirable qualities in a high-performance car.
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In terms of pure numbers, the ME is 44.9 inches (114 cm) tall, 78.7 inches (199.9 cm) wide and 178.8 inches (454.1 cm) long. It only seats two, but you probably wouldn't be taking the kids to grandma's for Thanksgiving dinner in this car, so it's not much of a drawback.
The body is shaped not just to look good, but to aid in performance as well.
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The computer-controlled active rear spoiler adjusts itself depending on speed and wind conditions, creating up to 925 lbs of down force at 186 mph. That serves to stabilize the car, increase traction, and aid in high-speed cornering. The rest of the body also creates down force, while underside components are designed to reduce lift from air getting under the car. While creating all this down force, the aerodynamic shape also directs air to the engine compartment, keeping that 850-hp beast cool.
American Supercar
The auto world is buzzing
about the ME Four-Twelve. Very few American auto makers have
created true supercars. The ME might set the standard for
supercars of the future.
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Wolfgang Bernhard describes it as "everything we've learned about creating exciting, desirable automobiles."
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