OriginalM3.info

From Munich with brio – Automobile

M3. “M” as in macho, muscle, and more fun. “M” as in M1, M5, M635CSi, and M535i. “M” as in Motorsport GmbH, the elite workshop in charge of the most desirable BMWs money can buy.

The BMW M3 is a true wolf in wolf’s clothing. Prepared in maître Wolfgang Peter Flohr’s Motorsport witch kitchen with the help of Paul Rosche (engine) and Thomas Amerschlăger (suspension), this car is about as subtle and inconspicuous as a Doberman pinscher in a pink loden coat. It will liven up American BMW showrooms early this summer.

BMW swears the Bavarian bat-mobile was wholly styled in-house, but these drag-cutting addenda look as though they were created by the combined forces of Zender, Airbus Industries, and Arnold Schwarzenegger. The tail spoiler, which seats about eight pigeons, obstructs rear vision. The flared boy-racer wheel arches are extremely vulnerable in heavy city traffic. And the deep air dam hates curbs, ramps, and snowdrifts.

But never mind. Together, these go-faster items more than compensate for the greater frontal area and the wider tires of the M3; they effectively reduce the drag coefficient from a poor 0.39 to a good 0.33.

As one might imagine, the parts that helped to obtain this impressive figure were not available at your friendly spoiler shoppe. They had to be specially desgined and made. Peter Flohr, managing director of BMW Motorsport GmbH, explains: “Take the fenders, for instance. They consist of steel, not fibreglass, and they are shaped this way to accommodate the ten-inch wheels fitted to the competition car. Examine the bumpers. Made of foam-covered, reinforced epoxy resin, they even meet the tough DOT safety standards. Or look at the car’s rear end. To smooth the airflow, to reduce axle lift, and to improve the directional stability, we fitted a more steeply angled backlight, a higher trunk lid made of polyurethane, and a more aerodynamic rear apron. These modifications may appear aggressive or even gaudy. But together with some less obvious measures like a nearly flush floorpan, they do serve a distinct purpose.”

When M3 development began in 1982, it was clear that the chassis, too, required special attention. The 3-series BMW has always been a tail-happy car, suffering from twitchy handling and a lack of traction when pushed to its limits. For a while, the Motorsport engineers contemplated curing these problems by equipping the M3 with the four-wheel drive hardware of the 325ix (due in the States as an ’88 model), but in the end this was discarded as being too heavy and too fragile for the 320bhp track version. To obtain a better weight distribution, the battery was transferred from the engine compartment into the trunk, which now also houses a bigger 18.5 gallon fuel tank and some reinforcement material. As a result, the front to rear axle load proportioning of the M3 works out at about 52/48 percent.

Chapter two in Thomas Ammerschlăger’s Good Chassis Guide entailed a complete redesign of the front suspension. After increasing wheel caster to enhance the straight-line stability and the steering response, the chief project engineer developed new steering knuckles, fitted the bigger wheel bearings from the 5 series cars, and replaced the four lug wheels with wider five lug alloys supplied by BBS. Other improvements were stiffer anti-roll bars front and rear, uprated springs and dampers, and a recalibrated power steering that is quicker and more précis. Whereas the semi-trailing arm rear suspension design was taken over virtually unchanged, the standard 195/65VR-14 tires were replaced by wider 205/55VR-15 gumballs. The braking system was beefed up with the help of ABS, thicker, larger diameter discs, heftier callipers, and an accordingly modified master cylinder.

The body and chassis changes may not be exactly revolutionary, but the engine fitted to the M3 comes as a surprise. Dressed in matte silver, shiny chrome, and black crackle paint, it is a sixteen-valve 2.3litre four with “BMW M Power” written all over its rocker cover.

A four? After all the hype emphasizing the superiority of the six-cylinder motor?

Senior drivetrain engineer Paul Rosche tries to explain: “The M3 was primarily developed for motorsport purposes. It is a production racer of which we must build 5000 units within twelve consecutive months. Of course BMW cold have fitted a six-cylindr engine, but in the end we opted for the four-cylinder unit based on the successful Formula 1 powerplant. This motor is not only lighter and more compact than a six, but it also provides us with a notably higher potential rev limit, vital when it comes to preparing the competition variants. While the power curve of the catalyst-equipped version peaks at 7100rpm, the track engine will happily rev to 9000rpm.”

Derived from the 24-valve 3.5 litre six, the 2302cc M3 unit boasts state-of-the-art ingredients such as two chain-driven overhead camshafts, a five-bearing crankshaft, pent-roof combustion chambers, a high compression ratio of 10.5:1 squish lips on the piston crowns, centrally located spark plugs, a fully electronic Bosch ML engine management system, an oil cooler, and a bigger capacity light alloy sump. This sophisticated powerplant develops 200bhp in free-breathing form, and 195 desmogged bhp. Maximum power is available at 6750rpm, and the torque curve peaks at an elevated 4750 rpm, when 166 pounds-feet are at hand. The 2569 pound BMW M3 accelerates in 6.9 seconds from 0 to 62mph, and tops 144mph. Our test car returned 20.3 miles per gallon, corresponding to a driving range of approximately 360miles.

The purposeful, no-frills cabin of the M3 stands in sharp contrast to the car’s jazzy exterior. Inside, the top-notch 3-series differs from a bog-standard 325 only by the addition of an oil temperature gauge, a leather rimmed steering wheel, and a set of four deeply contoured sport seats. Dollar prices are not fixed yet, but we can do some educated guessing. The German list price of 59, 800 deutsche marks (close to $30,000 these days) includes heated, remote-control door mirrors, tinted glass, and power-assisted steering. Add about 9000DM ($4500) for air conditioning, metallic paint, sunroof, radio, leather upholstery, and power windows and door locks. That means we have to expect the US price for an all-inclusive 1987 ½ M3 to approach a sobering $35, 000.

The long-stroke 2.3 litre four springs to life at the first turning of the ignition key. When cold, it needs a busy 1000rpm to idle properly, and although it reacts willingly to the slightest dab on the throttle, there is no doubt that this is a highly tuned, thoroughbred powerplant. As coolant and oil are warming up, the clanking and clattering of the valves and the droning of the exhaust are metallic, yet hollow. Once the engine has reached its working temperature, however, treble and bass blend to a full-bodied melodious tone that, with rising revs, reaches almost orchestral quality.

Only as far as its running characteristics are concerned, the M3 unit never comes close to a good six; it is actually not even as civilized as, say, the sixteen-valve four that is fitted to the Mercedes 190E 2.3-16. At 50mph in fifth, the Bavarian powerhouse hums along with drawn-in claws, but the instant you floor the throttle and unleash more revs, the hum becomes a growl, then a roar, and finally a shriek. As the needle of the tachometer climbs up to its 7100rpm peak, the driveline goes through a wide spectrum of subtle but irritating vibrations, ranging from a mild tremble to a high-frequency judder that can even be sensed through the accelerator and the gear lever.

This engine is a fighter; you can feel it working hard to deliver the goods, Throttle response is lightning fast; its willingness to rev gives an impression of incredible effortlessness; and there is always plenty of torque at hand to pull you out of trouble without the need for downshifting. The strengthened clutch is light and progressive enough, and the Getrag five-speed’s gears are well spaced for optimal performance. But the competition style shift pattern is awkward (first is down to the left), and the lever movements are a bit vague and slow.

Thanks to the standard limited-slip differential, traction is good on most surfaces, but with nearly 200bhp on tap and relatively lightly loaded rear wheels, the car demands caution in the wet and through tight low gear corners. Mercifully, the M3 does without the oops-here-comes-that-tail-again attitude for which many BMW models are notorious. Through bends fast and slow, this potent four-seater remains neutral for a long time. Once the limit is reached, the car will either slide into a slightly nervous four wheel drift or enter clearly defined and nicely controllable oversteer. As you back off, the weight transfer will pull the nose toward the apex of the bend, calling for a correction at the wheel. The power-assisted steering is well damped, quick and communicative, and the wonderfully progressive brakes deserve full marks for feel, precision, and balance.

Surprisingly enough, the ride comfort has barely suffered from the taut M-Technik suspension setting. Like its lesser brethren, the M3 is still no friend of potholes, bumps, and level railway crossings, but it does cope well with such dreaded vagaries as crests, grooves, and dips. On the down side, we noticed a certain instability in crosswinds, annoying tramlining on poor surfaces, and a rather high overall noise level (engine, tires, wind).

The BMW M3 is a sports car in disguise. It’s a lot more expensive (and not a lot faster) than an ordinary 325i. it has no super smooth engine, no family friendly suspension, and even less room in the back and in the trunk. It also does without reclining seats, an automatic transmission option, or any trace of chrome. But the M3 has – at last! – a thoroughly convincing chassis, and it is well made, sufficiently well equipped, and ergonomically faultless. Most important of all, it is a lot of fun to drive.