What happens when you redesign 80% of a car that has been on the market for less than two years, leaving only the glass, doors, trunk lid, lights, and load bearing structure in common with the latest variant? For many companies, bankruptcy is the next step in this progression. For BMW, it's just a step in the creation of the latest version of the M3. "Often, this is the only car in the household," says Larry Koch, M Brand manager, BMW North America, "so we had to make it usable." In truth, all M3s since the first E30-based version back in 1986-a car created so that BMW could build the 5,000 road versions required to race in the German Touring Car Championship-have been usable. They just haven't always been enjoyable off the track, a point punctuated by the first M3 with its 192-hp inline four-cylinder, and the last version with its 333-hp inline six-cylinder. Both have the high-strung edginess of a methamphetamine addict.

The M3’s V8 is lighter, more powerful, and more tractable than the inline six-cylinder of the last M3.

That wouldn't do for the latest version, especially with cars like the V8-powered Lexus IS-F moving into the M3's territory. So BMW borrowed 4/5ths of the 5.0-liter V10 found under the hood of the larger M5, mated it to Getrag-sourced gearboxes (a six-speed manual with a dual-plate clutch from the M5, or a new seven-speed dual-clutch semi-automatic), and built the resulting car around this powertrain. "The V8 produces 414 hp at 8,300 rpm," says Bernd Limmer, Technical Director, M3, "with 295 lb-ft of torque-85% of which is available from 1,800 to 8,300 rpm-at 3,900 rpm." The engine features an aluminum-silicon compound crankcase, iron-coated pistons running in uncoated honed cylinder bores, bedplate construc-tion, eight individual throttles, twin oil pumps capable of keeping the engine lubricated at 1.4 g, and hydroformed stainless steel exhaust manifolds. It also weighs 445 lb., which is 33 lb. less than the last M3's 3.2-liter inline six-cylinder engine.

Every tuner car has carbon fiber trim, so BMW decided to create a hand-stitched woven leather that mimics the composite’s checkerboard finish while adding a luxurious tactility it can’t match.

"We followed a simple formula to keep the wheel torque at an optimal level," says Limmer. That equation, Mdrad = iges x Mdmot, states that wheel torque = axle ratio x engine torque, and "resulted in a high rear axle ratio (3.846:1) matched to the engine output for the greatest acceleration off the corners," he says. To match that performance BMW specified cross-drilled compound brake discs and floating calipers for the best braking performance. "Ceramic brakes are a disadvantage on the road," says Limmer, "because they can't produce sufficient heat in most cases to stop in the shortest distance possible." Yet conventional materials often fall apart on the track. To accommodate both requirements, BMW engineers specified a design where the brake disc and hat are separated by pins that allow the disc to float above the hat, leaving it free to expand and contract as temperatures rise and fall without introducing any vibration or warping. The discs are 14.2-in. x 1.2-in. in front and 13.8-in. x 0.94-in. in the rear. Both use single-piston swing calipers that rotate the caliper around its top mounting after removing a single lower bolt. This makes it possible to remove the brake pads without changing the relationship between the brake and disc, or putting strain on the brake piping. The M3 also makes use of regenerative braking during overrun and under braking. Unless there is a need for it to recharge the battery while the engine is under load, the alternator remains disengaged.

Unlike the Coupe, the M3 Sedan does not have a carbon fiber roof, though its two extra doors should make it the vehicle of choice for a majority of buyers.

In addition to these changes, BMW completely rethought the suspension, saving only the rear longitudinal links from the standard-issue 3 Series. "We redesigned the thrust plate connection from the front struts to the front uprights, and triangulated the rear suspension from the lower outboard links forward to the body," says Limmer. "This cuts axle tramp and twist, and evens out the load on the suspension parts under extreme conditions." In addition, nearly all of the front axle components are now made of aluminum, as are the pieces for the five-link rear suspension. The latter includes forged control arms and aluminum dampers that contribute to a 5.5-lb. weight reduction. Electronic damping control adjusts the shocks only when there is a dynamic reason to increase damping forces, so that the ride stays comfortable for as long as possible. When activated, it makes the damper three to 12 times stiffer than normal, and works in concert with the hollow front and rear anti-roll bars to reduce roll in hard cornering.

(Not Much) Less Than 3

The larger wheels and tires and lack of fog lights distinguish the 135 from its less powerful sibling. The 1 Series hit the European market as a wagon-like four-door hatchback in 2004, but has taken four years to reach North America. First, there was the need to create a coupe and convertible suitable for this market. Second, the car needed a powerplant suitable for a BMW. Though the 1 Series shares about 60% of its components, including the front and rear suspensions, with the current 3 Series, it rides on its own platform, is 8.7-in. shorter than the 3 Series Coupe, and—in North America—is powered by a pair of 3.0-liter inline six-cylinders borrowed from the 3 Series. The 128 uses the normally aspirated 230 hp, 200 lb-ft of torque six-cylinder, while the 135 gets a twin-turbo version that produces 300 hp and 300 lb-ft of torque. Both can be mated to either a six-speed manual or a six-speed automatic also borrowed from their larger brother. A performance version is planned, but it will not be called the “M1” as that was the designation of BMW’s revered mid-engined supercar of the 1980s. Instead, the 1 Series will use the “tii” designation formerly used by the BMW 2002, a predecessor to the first 3 Series. In addition, BMW insiders say the 1 Series model range will expand in the coming years to include both a 2.0-liter gasoline and a twin-turbo 2.0-liter diesel engine. These cars promise to come in under the $29,375 (Coupe) and $33,875 (Convertible) pricing of the current 128 models.

The final drive uses what BMW calls "Variable M Differential Lock" to shift up to 100% of torque to the drive wheel with the best traction. Once wheel speeds equalize, however, the differential opens until the system recognizes a need for it to relock. According to BMW's Larry Koch: "This lock/unlock sequence is not only variable from 0% to 100%, it takes place about five times per second to ensure optimum traction on all surfaces." In the same vein, the optional Technology Package adds an "M Dynamic Mode" that lets the driver alter specific driving functions. These include the ability to choose from three levels of stability control (Auto, M Dynamic, and Off), three levels of damper control (Normal, Comfort, and Sport), three engine maps, and two levels of power steering response. Once set, the driver presses the "M Drive" button in the console to engage the system.

BMW engineers also added a carbon fiber roof to the M3 Coupe to cut 11 lb. from the highest point of the body and increase body rigidity. Finished in a clear paint, the panel is built at the company's Landshut, Germany, facility just north of Munich. In addition, the front fenders of all M3 models (Coupe, Sedan, Convertible) are thermoplastic; the hood is made from aluminum. Inside, BMW offers a number of trim options including woven leather that mimics the look of carbon fiber. "Each piece is hand-stitched and fitted to the trim piece that encompasses the air vents along the instrument panel," says Koch.

Designing Mini’s Clubman

The small Club Door on the passenger side was not part of the original Clubman design brief. Planning for the Clubman version of the Mini extends back to the Mark 1 model BMW introduced in 2001. Three designs were created, including a simple stretched version of the hatchback, the same basic car with a two-piece tailgate that featured the fold-down trunk lid of the Mini Convertible allied with a fold-up glass upper, and a design that borrowed the dual rear doors of the original Mini Countryman. “The Club Door on the passenger side was not part of the original plan because we could only stretch the wheelbase 60 mm on that car to keep the proportions,” says Clubman chief designer Marcus Syring. “When we moved on to the Mark 2 with its higher beltline and more upright hood and revised chassis, it supported the longer wheelbase we needed to add the third door” because a driver’s side door would have meant moving the fuel filler behind the rear wheel, adding to the overhang and harming the handling. According to Syring, the split rear door idea came from Mini design chief Gert Hildebrand who worked out the design and came up with the idea of contrasting panels at the door edges to allow the hinges to be moved as far outboard as possible while hiding them from view. With a 3.1-in longer wheelbase and 9.4-in. greater overall length, the Clubman began to lose the bulldog stance of the standard car, and was almost overpowered by the rising beltline. As a result, Syring’s team—which for a brief time had Rolls Royce’s interior designer working on the interior of the Clubman—raised the edges of the roof panel in a gentle curve so it “didn’t look so much like a mushroom top.” The longest roof panel in the BMW inventory, it has the same section through the center as the regular Mini since it uses the same panoramic sunroof, and the “Dune section” curve on top is nearly the same as the highlight line on the roof of the Rolls Royce Phantom Coupe. Unlike that character line, however, the Mini Clubman’s roofline has an aerodynamic purpose: “The raised sides funnel air so well we don’t need a rear spoiler on this car,” says Syring.