BMW is largely credited with inventing the sports sedan category, so it has a long history of making four-door cars that are track ready. The M3 is practically a fixture at NASA events nationwide, be it in racing or HPDE.
Over the last several years, BMW decided that having a 3, 5, 6 and 7 series wasn’t enough. The company wanted to gain share in different segments of the market and it began adding series to its model line. Before long, customers also could choose from three different SUVs in 1,3 and 5 designations. For cars, consumers now can select from 1, 2, 3, 4, 5, 6 and 7 series models.
The designations, 1, 3, 4, 5 and 6 are available as M model performance variants. Obviously, for serious track use the 1 and 3 series are your better bets, if for no other reason than their curb weights. If you can’t see yourself in an M5, BMW now offers the M4 in coupe and the M3 in sedan versions built on the same chassis. We had the chance to sample an M4 coupe at the Motor Press Guild Track Days program, a two-day event at Willow Springs International Raceway that brings together automotive journalists to drive the latest and greatest hardware from a variety of automakers.
Let’s start with the engine. There is perhaps no other manufacturer that has put more R&D into the dual overhead-cam inline six-cylinder than BMW. It seems every couple of years it comes out with an “all-new” engine fitted to its cars, and the M4 coupe certainly follows suit in that respect.
The 3.0-liter inline six features two single-scroll turbochargers, which combine to make 425 brake horsepower from 5,500 to 7,300 rpm. What’s more, it produces 406 pound-feet of torque from 1,850 to 5,500 rpm, which would be handy for getting off the corner quickly. Those figures are astounding for a 182 cubic-inch engine, no matter who makes it, and it’s not to bad on fuel, either. City mileage is 17. Highway is 26.
“The engine is the heart of every M model, and the new turbocharged six-cylinder unit fitted in the two new cars combines the virtues of a high-revving naturally aspirated unit with the strengths of turbocharger technology,” said Dr. Friedrich Nitschke, President BMW M GmbH. “A committed lightweight design concept produces a weight saving of around 80 kilograms over the outgoing M3. Meticulous and passion-fuelled development work has underpinned the creation of two high-performance sports cars that set new standards in terms of overall concept, precision and agility.”
The M3 and M4 can be fitted with either a twin-disc, six-speed manual, which is good for zero-to-60 times of 4.1 seconds, or an optional seven-speed M Double Clutch transmission that lowers the zero-to-60 time to 3.9 seconds.
Don’t let the “manual” in the six-speed’s name fool you. This transmission is as advanced as a manual gearbox can be. First off, the transmission is more than 26 pounds lighter than its predecessor. To enhance shift comfort, BMW engineers fitted it with carbon friction linings in its synchronizer rings. They also added dry-sump lubrication and an electronic feature that “blips” the throttle on downshifts, a function that was previously available only in the M Double Clutch transmission. Pretty slick.
The M4 also makes extensive use of aluminum in its suspension. Up front, the M4 uses aluminum for the control arms, uprights and subframes. In the rear, all the control arms and uprights also are aluminum. BMW also notes that there is a rigid connection between the rear axle subframe and the body, which improves suspension geometry and perhaps remedies the flex in that part of the chassis, which had been a problem in earlier 3 series cars used for racing.
Driving it on the track, we found the M4 had tremendous balance, as you would expect from anything with an M badge. Brakes also were up to the task of track use and the power is ample at nearly all rpm and throttle positions as the numbers suggest. However the stability control system, which BMW officials would not switch off for journalists during their test drives, tends to be a bit intrusive and minimizes the fun. If you’re going to use the M4 for track days, memorize how to turn the system off before arriving at the track.
The short story is that the M4 coupe delivers what you expect. It’s quick and responsive due to its reasonably low curb weight. It also exhibits great balance, which is valuable on the street and on the track.
|3.0-liter twin single-scroll turbocharged I6|
|425 @ 5,500-7,300 rpm|
|406 @ 1,850-5,500 rpm|
|Double-joint strut multilink|
|Independent, five link|
Rear axle ratio:
|3.46:1 limited slip|