Just two months ago we took you on a drive in a 2011 BMW 1 Series M prototype, the high-performance edition of the 1 Series coupe that BMW refuses to call the M1. We told you it had way more horsepower than the standard 135i, along with an overhauled suspension, bigger brakes and a wider track — as if you couldn't see that from those bulging fenders.
But we couldn't put hard numbers behind any of those claims. Now we can.
If It's Good Enough for the 335is
Approximately forever ago we learned the 2011 BMW 1 Series M Coupe would use a version of BMW's N54 engine (no, not the newer, single-turbo N55). This is the twin-turbocharged and direct-injected 3.0-liter inline six-cylinder that we liked so much in our long-term 135i.
Exactly how much horsepower the engine would make in the 1 Series M has been the subject of intense speculation. We've heard guesstimates as high as 350 hp and as low as 335. Now here's the truth: The twin-turbo straight-6 is rated at 335 hp at 5,900 rpm and makes 332 pound-feet of torque at 1,500 rpm (with a short-lived 369-lb-ft hit available on the overboost). Redline is tagged at the 7,000-rpm mark.
The 1 Series M offers 35 more hp and 32 more lb-ft of torque than the 135i (which adopts the single-turbo N55 engine for 2011). Moreover, its power ratings are identical to the 2011 335is and 2011 Z4 sDrive35is, which use the very same N54 engine.
Relax. It's Still Going To Be Quick
But don't get disappointed just yet. This is still going to be a very quick car, and you'll only be able to get in on the fun if you can work a third pedal. Yep, despite the fact that a dual-clutch setup might actually turn better numbers, no such setup will be offered in the 2011 BMW 1 Series M.
With a conventional Getrag six-speed manual gearbox driving the rear wheels, BMW estimates the 1 Series M will hit 60 mph in 4.7 seconds on its way to a 13.2-second quarter-mile. Those claims are likely a bit conservative, as our stock long-term 135i ran a 4.8 and a 13.4, respectively. Note that the 1 Series M has a slightly shorter final-drive ratio than the stock 135i and the 335is: 3.15 versus 3.08.
BMW has fitted the transmission with a heavy-duty flywheel and, wisely, a dry-sump cooling system so you don't overcook the transmission fluid when you take your 1 Series M to a track day. There's an M button on the steering wheel, but instead of unlocking more power, it merely alters throttle response.
The other big upgrade on the Motorsport 1 Series is a standard electronic limited-slip rear differential ("M differential lock" in BMW terminology). So unlike 135i and 335is drivers, you're not going to get hung up spinning that inside rear wheel as you exit a corner. We'll trade an extra 10 hp for the ability to put the power to the ground effectively any day of the week.
A Chassis Transformed
Meanwhile, the changes to the BMW 1 Series chassis are as radical as the engine upgrades are subtle. BMW Motorsport engineers have taken the all-aluminum front strut/rear multilink suspension from the M3 and put it under this 1 Series coupe. This saves all kinds of unsprung weight and no doubt contributes heavily to the 1 Series M's overall 77-pound weight loss compared to the 135i.
Though the suspension geometry had to be altered to fit the 1's narrower track, surprisingly, the track widths of the 1 Series M and M3 differ by only 0.2 inch (60.5 inches vs. 60.7, respectively). What those fenders can't begin to hide is that the Motorsport 1 Series has its front wheels pushed 2.8 inches farther apart than a 135i. The rears are 1.8 inches farther apart. This changes everything, and we noted that the 1 Series M prototype had higher limits and a more neutral cornering attitude — a welcome change from the 135i's tendency toward understeer.
The 1 Series M borrows its lightweight 19-by-9-inch front and 19-by-10-inch rear wheels from the M3 Competition Package and the Europe-only M3 GTS. Mounted on these wheels you'll find tires measuring 245/35R19 front and 265/35R19 rear. BMW hasn't specified the tire model on U.S.-spec 1 Series Ms, but the prototype had Michelin Pilot Sports.
The steering system retains hydraulic power assist, and it felt pretty solid on the prototypes we drove. Could be even better on the production models, as the M division engineers have some time to fine-tune it before the first cars arrive in the U.S. in the spring of 2011.
Brake hardware is shared with the current M3, and consists of 14.2-inch cast-iron ventilated front discs, 13.8-inch ventilated rear discs and single-piston sliding calipers all around. This is a notable upgrade over the 13.3-inch front and 12.8-inch rear rotors on the 135i.
Beyond the wider track, the other cosmetic changes you'll notice on the 2011 BMW 1 Series M are the 4-by-1-inch ducts cut into the corners of the front and rear fascias. BMW calls them "air curtains," and they smooth out air flow underneath the vehicle, reducing turbulence as you're flying through a sweeper. BMW says this aerodynamic measure comes straight from the original Vision EfficientDynamics concept car and reduces the car's rolling drag coefficient by 0.01.
A lip spoiler on the 1 Series M coupe's rear deck provides a little extra downforce at speed without breaking through the barrier of good taste. The quad tailpipes might well demolish that barrier, but we don't care. They make this little coupe look tough and give it an exhaust note all its own.
Other details include the M3 side mirrors, which are more aerodynamic than stock 1 Series mirrors. Headlights are the same excellent adaptive bi-xenons we had on our long-term 135i.
Inside, the dash, door panels, instrument binnacle, and shifter and handbrake boots are upholstered in black Alcantara trim with contrasting orange stitching. The steering wheel is covered in leather, rather than Alcantara, because no one wants to hold a suede steering wheel drenched in his own perspiration.
The seats are black leather items with considerable lateral bolstering and yet more orange stitching. Why orange? Well, because, Valencia Orange is the exclusive exterior paint option on the 1 Series M. If you want something more boring, there's Alpine White or Black Sapphire Metallic.
Should you forget for even 1 second that you're in a Motorsport BMW, a quick look at the gray-faced gauges with red pointers will set you straight.
Horsepower Doesn't Matter?
The huge power ratings in the M3 and M5 have conditioned us to expect something bigger and better on every successive M car. But a new era is upon us, and in this era, performance cars will have to consume less fuel, emit fewer emissions and generally be more responsible.
And so we have the 2011 BMW 1 Series M, which makes all of 335 hp. That seems like such a modest figure today, but it would have been unthinkable back in the 1980s when the original E30 M3 was on sale. That car made all of 192 hp in U.S. specification. Of course, unburdened by modern safety equipment, it also weighed 400 pounds less.
No doubt the carmaker would like to recast the 2011 BMW 1 Series M as a spiritual successor to that beloved M3. That's a pipe dream, but if the 1 Series M coupe is even half as much fun to drive as that old car (and as reliable as a 21st-century BMW), BMW should have a nice little hit on its hands.