December 09 2010   Source: Bryan Joslin


BMW Pulls Wraps Off 1 Series M Coupe

BMW today unveiled what is perhaps the most eagerly anticipated model to come out of its M division in recent memory, the 335-hp 1-series M Coupe. We got a first look at the little hot rod earlier this year, and now full details have been announced.

The 1-series M Coupe is based on the popular 135i coupe, but gets a healthy attitude adjustment from the guys at M. Two years of development means more power, less weight, a dialed-up suspension and some serious bodywork to contain it all.

Power comes from a modified version of the 3.0-liter twin-turbo N54 engine that originally powered the 135i. Output has jumped from 300 horsepower at 5900 rpm to 335, with an increase in torque from 300 lb-ft to as much as 369 lb-ft by way of an overboost function, as in the 335is and Z4is. This extra shot of boost is good for up to seven seconds at a time under full throttle conditions, otherwise torque is delivered at 332 lb-ft over a broad range from 1500 to 4500 rpm. BMW claims a freer-flowing sport exhaust system has been acoustically engineered to deliver the kind of song that goes hand-in-hand with this kind of performance, though some early reports say it doesn't quite live up to the promise.

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In a move presumably made to keep the price of the 1-series M attainable, a six-speed manual transmission is the only option. The chosen gearbox is purpose-built for high-torque applications and features a heavy-duty flywheel and a dry sump cooling system. Shifting is done through a short-throw M gear lever. A shorter 3.15:1 final drive ratio was selected for spirited acceleration, though it will still reach an electronically limited 155 mph top speed. BMW's Variable M differential lock addresses one of the 135i's major shortcomings, locking up both left and right wheels under hard acceleration for maximum traction under power.

As with other recent M models, the 1-series M Coupe utilizes an electronic M Dynamic Mode (MDM) which alters the stability control settings to allow a driver to extract as much performance from the car as possible without overstepping its limits.

From the outset, one of the priorities for the 1-series M Coupe team was to develop a car whose chassis is "faster than its engine." To that end, the car features reworked geometry in the rear to deal with the unique kinematics of the 2.8-inch wider front and 1.8-inch wider rear track. Nearly every part in both the front and rear suspensions is rendered in aluminum, down to the shock absorber bodies. Hollow-section sway bars are also fitted at both ends for increased roll resistance without additional weight. The setup was designed for use on the track as well as the street, and the additional chassis width, especially up front, should make the 1er M a more neutral platform in hard cornering.

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Brakes, of course, are part of the aggressive chassis formula. Up front, 14.2-inch vented and cross-drilled compound-construction discs — iron rotors floating on aluminum hats — are gripped by the single-piston calipers originally seen on the current M3. In back, 13.8-inch discs of the same construction are also from the M3.

The big brakes are wrapped in huge rubber, with 245/35-19 tires fitted to nine-inch-wide wheels at the front and serious 265/35-19s on ten-inch-wide wheels out back. The wheel of choice is the cross-spoke design specifically from M, the same wheels seen on the M3 GTS and M3 Competition Package, finished in silver paint.

To contain the wider suspension and massive rolling stock, the 1-series body had to be widened accordingly. The sheetmetal below its distinctive beltline is all new, resulting in a 2.1-inch width gain overall. The resulting look is noticeably more aggressive, though much more subtle than the box fenders on the original M3. The new front fenders feature a subtle new twist on M's signature side "gills," while a mild spoiler on the trunk lid aids downforce at high speeds. Like the trunk spoiler, the new front fascia was developed in BMW's rolling-road wind tunnel, including the new "air curtain" that reduces turbulence of air flowing over the outside of the front wheels.

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Unlike other M vehicles of late, no carbon fiber has been employed in the roof panel, again to keep costs down. However, the 1-series M Coupe will only be offered without a sunroof, which saves 35 pounds, all of which normally lives at the highest point in the car. Overall, the 1-series M Coupe sheds a total of about 77 pounds from a regular 135i coupe, weighing just under 3300 pounds, with a nearly ideal 51.7/48.3 front/rear weight distribution achieved. Between the added power, extra grip and reduced weight, BMW claims the 1-series M Coupe should be capable of getting to 60 mph in 4.7 seconds, but based on our own experience with a long-term 135i we're guessing that figure is conservative; a 4.4- to 4.5-second time is likely possible under good conditions.

The 1-series M is fitted with xenon headlamps as standard, and they include the new integrated "eyebrow" that helps give the car a more focused look going down the road. All 2012 1-series coupes will also get the updated lamps, along with the new taillights seen on the M model. Three colors will be available, with the Valencia Orange Metallic seen here being exclusive to this model; otherwise Alpine White and Black Sapphire Metallic are available.

The interior gets a treatment to match the bodywork, trimmed in a host of blacked-out materials. The standard sport seats are trimmed in black leather with orange stitching, and the leather M sport steering wheel features the brand's distinctive three-color stitching on the inside of the rim. Black Alcantara, again accented with orange stitching, cover the instrument housing and all the places where wood or aluminum would normally reside, as well as the shift boot, parking brake boot and door panel inserts. The headliner and pillars are trimmed in black mesh cloth to round out the look. Other M details include aluminum doorsill plates and footrest, but oddly not the remaining three pedals, which get the same rubber pads as any other 1-series.

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The 1-series M Coupe may very well be the purest spiritual successor to the original M3, and it's certainly what younger enthusiasts have been clamoring for since the 135i was introduced here three years ago. When it goes on sale this spring, it will be the least expensive, most attainable M model available. Final pricing will be announced closer to launch, but we're expecting numbers in the mid-40s. The car will be on display at the North American International Auto Show in Detroit next month, and we hope to bring you a drive report soon.