M - Not Just 007's Boss, It's the Mark of a Very Special BMW:
BMW Motorsport is a unique operation. As a wholly-owned subsidiary of BMW, Motorsport
supports private BMW racing teams, conducts factory racing programs and creates
high-performance components for BMWs. But Motorsports' most visible products these
days are a line of special high-performance M-designated BMWs.
While the first car released with an M badge was the M1 in 1989, the BMW M story
starts nearly 10 years earlier. BMW Motorsport GmbH was formed in 1972 and headed
by Jochen Neerspach: it was set up to guide and aid BMW's motorsports effort around
the globe.
The first project was to turn the BMW CSL coupe into a winner in the European Touring
Car Championship (ETCC). Ford had been dominating this series in the early '70s
with their Capris, but by 1973 the CLS, an M-modified, lighter version of BMW's
3.0CS coupe, began dominating the ETCC. BMW won that championship from 1973 through
1979.
The CSL, or "Batmobile" as it came to be known because of its then-radical wings,
also came to America. In IMSA competition, the CSL won the Sebring 12 hour race
in 1985 and the 24 hours of Daytona outright in 1976.
Porsche started to dominate professional sports car racing soon afterwars with their
935 and 936 derivatives, and after a brief but decidedly mediocre stint racing 320i's,
BMW decided to look elsewhere for a place to play.
Enter the M1
The first car that BMW Motorsport produced was the incredible mid-engined M1. Originally
released in 1978 to race in Europe's Group 5 competition, production and homologation
problems kept the M1 from racing until 1981. At that point, the car was no longer
competitive and was quietly discontinued.
Initially, the Giugiaro-designed car was to be assembled by Lamborghini, but after
only a handful of prototypes were built, Lamborghini's worsening financial situation
and assembly delays caused BMW to move assembly to Baur (the German convertible
builders).
Production resumed, and cars were quickly entered in the Procar series. This one-make
series, designed to sell the required 400 cars for Group 5 homologation, was run
in 1979 and 1980.
The M1's biggest success came in 1981 when David Cowart and Kenper Miller won the
IMSA GTO category in the Red Lobster-sponsored M1.
The M1 was designed around the 3.5-liter straight six that powered the company's
more mundane sedans. With a 24-valve head, the engine put out 277 horsepower at
6500 rpm. This was the same engine that would go on to power the M6 in 1987.
M6: The Ultimate Luxury Performance Coupe
The BMW M6 was outwardly similar to the familiar 6-Series coupe (635CSi) except
for certain significant details, such as its wide, large-diameter cross-spoke forged
alloy wheels, correspondingly low and beefy tires, a discreet spoiler on its rear
deck and its all-important M6 emblem.
But it's inside the sleek four-seater coupe body where BMW Motorsport worked its
real magic. Under the M6's hood is an updated version of the M1's exotic engine:
a 3.5-liter, dual-overhead-cam, four-valves-per-cylinder six-cylinder engine.
Designated the S38, this 24-valve engine developed 256 horsepower and was capable
of accelerating the M6 from 0 to 60 mph in just 6.8 seconds. Like other BMW six-cylinder
engines, the S38 had inline cylinders, a cast-iron block and a crossflow aluminum
cylinder head. Fuel injection and ignition were electronic, controlled by the Digital
Motor Electronics engine-management system.
From these BMW basics, the M6 engine went its own way with an array of high-performance
features: short-stroke engine design for higher rpm; a slightly larger displacement;
chain-driven, dual overhead camshafts; four valves per cylinder in V-formation,
actuated by cup-type lifters; hemispherical combustion chambers; high compression
ratio (9.8:1); individual throttle plates for each cylinder; machined intake and
exhaust ports; honed cylinders; dual exhaust system; low-restriction catalytic converter;
oil cooler mounted in the front spoiler; and a 6800-rpm redline.
M6 power was transmitted through a heavy-duty Getrag 280/5 five-speed transmission
with specific gearing for the M6 engine. A 3.91:1 limited-slip differential was
also included.
In its fundamentals, the M6 chassis was like that of all larger BMW models, with
double-pivot, strut-type front suspension and Track Link semi-trailing arm independent
rear suspension linked to a rigid unitized steel body-chassis.
The M6 sat 4/10-inch lower, and its rear springs were progressive-rate for firmer
handling without sacrificing riding comfort over small bumps. Bilstein gas pressure
shock absorbers were fitted all around.
For better straight-line stability at very high speeds, Motorsport engineered in
extra steering caster and gave the variable-assist steering even firmer road feel.
The front ventilated disc brakes were enlarged from 11.2 inches to 11.8 inches in
diameter. Completing the running gear were extra-wide, cross-spoke forged alloy
wheels. 415x210 TR (16.3x8.3 in.) fitted with Michelin TRX 240/45VR-415 tires.
The M6 interior was more luxurious and sportier than past 6-Series coupes. Its seats,
doors, rear side panels, lower dash and center console were covered in hand-cut,
hand-stitched Nappa leather. An adjustable thick-rim leather sports steering wheel
and M6 instrumentation, including a 170 mph speedometer and an 8000-rpm tachometer,
rounded out the interior.
The M6 was produced only in 1987 and 1988; somewhere around 2500 were built during
these two years.
M5: BMW Motorsport Builds a Performance Sedan
Built only in 1988 (in E28 guise), the M5 combined the understated syling and sedan
practicality of the BMW 5-series with all the potency and luxury of the M6.
Under the hood was the same 3.5-liter, 24-valve, dual-overhead cam engine that powered
the M6. Here, too, the power was transmitted through the semi-close-ratio five-speed
gearbox and limited-slip differential.
Brakes and chassis modifications were also very similar to the M6, and the interior
was nearly identical. One notable change was the thankful deletion of TRX tires
and wheels. The M5 came equipped with 225/50VR-16 tires on BBS 16x7 1/2-inch cast-alloy
wheels in cross-spoke design.
Outwardly, the M5 was set apart from other 5-Series sedans by the sports wheels
and tires, a deep front air dam with integrated fog lights, a rear-deck spoiler,
black trim, and M5 emblems in the grille and on the trunk lid. It was pretty subtle,
although enough to indicate the special nature of the M5.
The M5 was only available in black with natur (beige) leather, and only about 1200
were built
M3: The M Car for Boy Racers
While the first three BMW M cars were designed to be ultimate high-performance luxury
cruisers, the M3 was designed for only one purpose: to get around a race track very
quickly. Naturally, this makes the (E30) M3 very popular with true enthusiasts.
Introduced in 1988 and based on the then-current (E30) two-door 3-Series, much of
the M3's skin was new. It featured new front and rear fenders, doors, rocker panels,
rear roof section, trunk lid, a deep front spoiler and a wing over its higher trunk
lid, body-ciolored deformable plastic bumpers, almost no chrome, lowered suspension
and wide sports tires.
The M3 looked serious from the outside, but it got even more serious underneath
its aerodynamic body. Its front suspension was all-new and built to race-car standards.
Beefy two-piece forged steering knuckles with five wheel bolts provided strength
and lightness at this critical connection between suspension and wheels. For strong
steering feel there was three times the caster of the production 3-Series suspension;
this effect was enhanced by a quicker steering ratio and power steering that was
valved for more feel.
By linking the front anti-roll bar to the struts instead of the lower suspension
arms, it had double the effect. The rear anti-roll bar was larger than on the standard
3-Series cars, while front and rear tracks were wider. Twin-tube gas-pressure shock
absorbers were fitted all around, and the whole suspension system was set almost
an inch lower than that of the 325i.
The M3's brakes were downright huge for a car of this weight (2735 pounds): 11.0
inches at the front and 11.2 inches at the rear. As in other BMWs, ABS was standard.
The wheels were BBS cross-spoke alloys, sized 15x7 inches, and carried 205/55VR-15
tires.
Designated S14 by BMW Motorsport, the M3's engine can be interpreted two ways: as
a four-cylinder version of the S38 engine that powers the M6 and M5 (with which
it shares bore and stroke), or as a roadgoing version of the BMW Formula 1 engine
that won the Gran Prix World Championship in 1983.
Either way, this was a racing engine tamed for the road. Its cylinder head had chain-driven,
twin-overhead camshafts, four valves per cylinder and precision-machined intake
an exhaust ports. Individual throttles for each cylinder ensured not only maximum
power, but clean exhaust and reasonable fuel economy. The compression ratio was
10.5:1
Tuned intake pipes and a new Ml-3 Digital Motor Electronics engine management system
supplied the engine its air, fuel and ignition. The dual exhaust system was racing-style
too, with a welded tubular header feeding into a twin-path, low-restriction catalytic
converter. Cylinders were honed smooth to allow reliable operation at up to 7250
rpm, and the oil pan was baffled to prevent foaming at such high revs.
Like the ports, the classic racing-type hemispherical combustion chambers were precisely
machined. The crankshaft had eight counterweights, versus four for the typical four-cylinder
engine, for the balance that's critical at very high engine speeds.
All this racing technology led to some very tangible results. One was on ouput of
192 horespower, reached at 6750 rpm - truly impressive for a 2.3 liter engine.
The M3 was only available with a five-speed manual transmission and a 4.10:1 limited-slip
differential; so equipped, it could accelerate to 60 mph in 7.6 seconds and reach
a top speed of 143 mph.
E34 M5: More luxury, Less Performance
In 1991 BMW introduced another M5, based on the larger, heavier, but more refined
E34 5-Series chassis. This car, while not designed for track use, would prove to
be one heck of a way to get from point A to point B in a hurry.
The M5 used essentially the same engine as the M1, E28 M5 and the M6. This time
around it was even further modernized with a slight stroke increase (which upped
the size from 3453cc to 3535cc); improved intake, exhaust, cam profile and fuel
management systems were also included. The net result was power increased from 256
to 310 horsepower. It's a good thing, because the wright of the car had also gone
up about 500 pounds.
The M5 also gained the usual M chassis, interior and exterior upgrades. The primary
difference was that the M5's modifications were much more subtle compared to previous
M products.
The M5 again disappeared in 1993 after only about 1600 were built.
E36 M3: More is Definitely More
We were along for the ride when BMW introduced the all-new E36 M3 to the press in
the spring of 1995, and we instantly became fans. Other members of the press felt
the same way, and the awards and accolades quickly started to pour in. Trophies
and checkered flags soon followed.
We covered the history of the E36 M3 extensively in the Nov/Dec '97 issue, but we'll
give you a quick recap. When building the earlier E30 M3, BMW basically built a
race car for the streets. With the E36 M3, they softened their approach a bit and
instead offered a higher-tuned version of the company's already-impressive 325is.
BMW released this second-generation M3 as a 1995 model, a year after the standard
coupe was shown.
While the E30 M3 featured a model-specific engine, the new US-spec M3 shared its
block and head with the 325is. Increasing the bore by 10.8mm and the stroke by 2mm
gave the new M3 three liters of displacement (over the 325's 2.5 liters); Motorsport
also enhanced the flow characteristics of the 325's cross-flow, four-valve head.
However, the M3 features different cams with more lift to meet the needs of the
massaged cylinder head. Thanks to these modifications, the 1995 M3 makes 240 hp
at 6000 rpm and 224 ft-lbs of torque at 4240 rpm. The standard 325is offers 189
hp at 5900 rpm and 181 ft-lbs at 4200 rpm.
An even hotter engine, featuring individual throttle bodies for each cylinder, was
available in European and Canadian markets but unfortunately not here in the States.
Setting the new M3 apart from the rest of the lineup were a subtle airdam, small
trunk spoiler and modified rear apron. Underneath, the ttransmission mounting points,
driveshaft central bearing mounting area and differential carrier mounting areas
were reinforced.
Firmer springs, thicker anti-roll bars and firmer gas-charged struts helped the
handling, and the front geometry was modifiedto improve steering characteristics.
To keep the car under control, the larger brake rotors and calipers from the M5
were fitted. Up front you will find 12.4-inch rotors, while out back you will see
a pair of 12.3 inch rotors. All are vented.
In 1996, displacement was increased to 3.2 liters; the following year, a four-door
M3 was offered.
Buying an M Car Today
M cars are still readily available, which is handy if you want to buy one. Because
of their expensive and prestigious nature when new, most have been well cared for.
The first place to look is in the BMW CCA's Roundel magazine, as dozens are
for sale every month.
The exception is the M1. These cars are rare, and prices never really go below the
$100,000 mark.
M6s are still readily available in the mid-$15,000 range. They still make great
daily drivers, but high weight makes the M6 somewhat of a disappointment on the
race track.
E28 M5s are also easy to find. Prices range from about $12,000 for a high-mileage
or ratty car to about $18,000 for a really nice one.
According to BMW M brand Manager Erik Wensburg, (Note:Erik has retired from BMW
since this article was written) the E34 M5 with its 310 horsepower and thoroughly
modern feel, is perhaps the best deal out there in M land. These cars can be picked
up all day long in the low- to mid-$20,000 range. Again according to Wensburg, the
one to have is the 1993 model with its better-looking wheels and other subtle improvements.
E30 M3s had actually dipped below the $10,000 mark a few years ago, but with the
introduction of the E36 M3 interest has resurged, along with prices. Expect to pay
$12,000 to $15,000 for a decent early car. You could pay as much as $20,000 for
a nice 1991 model
Be careful when looking for one of these cars, because many have been modified or
raced. If you want a street car, not a track car, you will probably be happier with
an M5 than an M3. The E30 M3 is buzzy and rides rather hard for daily use.
E36 M3s are holding their value well. When introduced in 1995, base price was $35,900
(without limited slip, a necessary option). Base price has now risen to just over
$40,000. You can get a nice used one for just over $30,000, although we have seen
them priced as low as $27,000 (probably high-mileage rats).
These might seem like high prices, but any of these cars will be good for over 200,000
miles if well maintained. Personally, for the price of a new Honda Civic, we would
much rather drive a 10-year-old M3 or M5. Do be careful when buying one of these
cars. While durable and well designed, if anything major does go wrong with a BMW
M engine, the repair bill will be in the $3000-$10,000 range. This could quicly
kill a good bargain.
Story by Tim Suddard * Photos as credited
Reprinted with permission from Grassroots Motorsports
March/April 1998 issue
(904) 673-4184
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