The M3, old news or not, is so well balanced that it is a benchmark by which other performance cars must be measured – Sports Car International
An M3? Come on, guys, that’s ancient history, isn’t it? Well, in some ways you’d be correct in saying that about BMW’s little sedan race. But when we started testing tuner M3s – cars supposedly capable of outperforming that factory offering – we discovered something interesting. Mechanically, the tuner cars were no improvement over the stock M3; in fact, not only did they prove less drivable, but they couldn’t match the standard Bavarian’s performance at the track, either. Which made us think the M3 deserves a place in our rapidly growing “Track Test” data base. The M3, old news or not, is so well balanced that it is a benchmark by which other performance cars must be measured.
When BMW set out to compete in the international touring car championships of 1987, they needed a special car. The rules for Group A racers required that manufacturers build within any given 12 month period 5000 cars essentially similar to the racers. To gain a bit of “unfair advantage,” Munich started with the body of their 3-series and created a special production model incorporating a good number of tweaks and subtle modifications useful for racing. In the time-honoured tradition that has prompted carmakers to produce such customer cars as the Plymouth Roadrunner Super Bird, Ford Mustang Boss 429, and Porsche Carrera RS, BMW created a roadgoing “funny car” to allow putting the same tweaks on their racers. The result is the M3, a race car for the road.
The exterior is extensively modified from stock. The fender flares are tastefully done, and look designed in, not just added on afterward to clear wider tires (the rules allow up to 10.0 inch wheels in touring car racing, with no body changes allowed). The entire rear window area has been altered for better aerodynamics on the race track. The bottom edge of the rear glass has been moved back several inches, giving it a steep rake. A composite cap fairs in the glass to the existing body. The trunk lid has been raised by another composite cap which carries the spoiler. Fit and finish are excellent.
In contrast to the rest of the 3-series BMWs sold in the US, which use the inline six, the M3 uses BMW’s venerable iron block four. The iron four has been around for more than two decades. The old block is fitted with a double overhead cam 16-valve head which benefits from the many years BMW has spent in tuning and racing this engine. This is a natural choice for racing, as the newer aluminum engines from Munich are perfectly good for civilian use but were never intended to put out as much as the racers need to be competitive, and are not as structurally rigid. As evidence of the four’s ultimate ability, recall that this humble block was also the basis for BMW’s successful Formula One effort of the early eighties. At nearly 200 horsepower, the M3 engine is probably at the very limit of what a 2.3 litre normally aspirated engine can develop for street use. The tuner cars we tested proved this point emphatically.
While the outside changes are obvious, the changes under the skin are even more extensive. The front suspension pickup points have been subtly altered from those of the stock 3-series. The front hub carriers are also different, for more caster, lending greater stability and better road feel. The ratio of the power steering has been quickened. Lower A-arms are of aluminum rather than steel. Springs, shocks, and bushing have been altered from stock, with rising-rate springs added at the rear. The M3 carries the bigger brakes of BMW’s 635 and 7-series. Power reaches the ground through a 25percent limited slip differential.
Inside, the M3 has excellent, multi-adjustable, highly supportive leather seats with high, firm side bolsters. Along with the Corvette and Porsche 911, these are among the best sports car seats anywhere. The steering wheel is set high, at a steep angle. It offers good grip, with perfectly placed thumb hooks. The instrument panel and controls have that characteristic no-nonsense BMW look and feel that says “this is a driver’s machine.” Instruments, controls, and pedals are all ideally placed. The dead pedal and the placement of gas and brake for heel-and-toe downshifting tell you that this is a car with sporting intentions. The heating/AC controls and the trip computer are clearly, logically labelled. The large glass areas allow good vision to all sides. Rear seating and headroom are adequate. The carpeting and trim pieces fit perfectly.
On the drag strip, the M3 launches best at 4300 to 4500rpm. We measured 0-60mph in 7.38 seconds, and the quarter mile in 15.65 seconds at 90.8 mph. The M3 has very short gearing, as one would expect in a race car. Second gear only reaches to 53mph. It’s tempting to say that car would be quicker with taller gearing, but the shifter feels so good that there probably isn’t much time lost in the extra shift before 60.
We measured a top speed of 139mph (the factory claims 142; close enough). Revs at top speed were 6900rpm, just 100 shy of redline. At that speed, the M3 felt securely planted, no doubt in part due to its racing modifications. The steering conveys a solid, well connected feel at speed. The M3 also retains that typical BMW ability to absorb big bumps while still delivering sharp handling characteristics. On the skidpad, the M3 exhibits very benign handling. We played around with tire pressures. Reducing pressure at the rear (to 38 psi cold all around) reduced understeer and made the car easier to steer with the throttle (it tucked in a little more on lift off) but didn’t affect ultimate cornering levels. The car could be kept on the line with the steering wheel held steady, and steered with just the gas pedal. At the limit, the car understeers gently. We measured average lateral acceleration at 0.81g. This car would do considerably better on the skidpad with more aggressive tires; the Uniroyal Ralleye is not today’s hot set-up. The narrow general-purpose tires may also account for the good but not stellar braking distances; this sort of car with ABS is capable of shorter stops. A sticky 255/50 tire would fit nicely, requiring no changes to the car.
The engine feels rough below 1500 or even 2000rpm, but smooths out above that, although it never approaches the levels of smoothness of BMW’s other engines. It has a growly sound and character, in the best tradition of four cylinder sports cars of a bygone era.
On the road, the car gives a false impression of sluggishness if driven conservatively. If the revs are kept too low, the four cylinder engine and deficit in low-end torque make themselves felt. If never taken out on an empty, twisty road, many drivers would overlook this car’s outstanding sporting character. The engine doesn’t have that strong bottom-end character of an American muscle car; it’s tuned for top end performance. When driven as intended, on a twisting road with the engine never dropping below 4000rpm, everything suddenly falls into place. The engine rockets the car from corner to corner, and the hard pedal of the ABS-assisted brakes lets the driver go into turns deep than he had thought possible.
Many cars feel fine when driven moderately hard, but lose their composure when going above eight or nine-tenths; not the M3. The feeling is one of being in total control even at ten-tenths. In short, the BMW M3 feels like a racing sedan. Which is exactly what it is.
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June 25, 2009
1990 - 1999, Articles