The new BMW M3 "The same specific loads as in Formula 1" Interview with Gerhard Richter, Director of Development at BMW M

Munich, Germany... Boasting a technical heritage in motorsport, BMW M Cars is
well known for its use of high-revving normal-aspiration power units. Now BMW
is continuing its philosophy with the new M3, focusing again on a high engine
speed concept.
Before the new M3 enters the market in autumn of this year, Gerhard Richter,
Director of Development at BMW M, explained the benefits of a high revving
normal-aspiration engine.

Every motorist can imagine what high engine speeds mean to performance, but
what is the nature of this concept based on from the outset?

Richter: We see high engine speeds as the most intelligent way to deliver high
power and performance from a compact engine. And we are well acquainted with
high engine speeds based on our experiences in motorsport. For example, in a
modern Formula 1 engine, the crankshaft rotates up to 18,000 times a minute
with each of the 10 pistons covering about 25 meters of piston travel every
second. The high-speed engine concept of Formula 1 is the same principle we
apply to our M engines.

By comparison, what engine speed is the new power unit of the M3 able to
achieve?

Richter: The straight-six power unit in the BMW M3 is an all-new engine that
revs up to a speed of 8,000 rpm - a speed that no other comparable straight-six
production engine is able to achieve.

You were talking about torque - what does that really mean in practice?

Richter: Ultimately, it means the power that accelerates a car. Following
simple laws of physics, the torque is always proportional to the car's actual
acceleration. In other words, the higher the speed of the engine - in
combination with the best possible transmission ratio - the greater the torque
you get when accelerating. This is the actual feeling of acceleration the
driver experiences behind the wheel. The torque is tangible- and much more
apparent to a driver than high horsepower numbers.

Does that mean that the engine power of a car claimed on paper doesn't say that
much about its actual performance?

Richter: Right. There are various ways to develop high power. Some
manufacturers prefer engines with lots of cubic capacity- but running at low
engine speeds. The disadvantage of such a power unit is that it takes up a lot
of space, weighs allot, and normally consumes a lot of fuel. Other
manufacturers like BMW, prefer compact engines revving at a higher speed -
which is precisely the approach we take with BMW M. Our main objective is to
keep the engine relatively small and compact, to use less space and material,
and to keep fuel consumption to a reasonable level. All this, we believe, is
crucial to the realization of a sporting and dynamic car.

Wouldn't a turbocharged engine be a good alternative in that case?

Richter: This is indeed the principle that some manufacturers prefer. But in
our experience turbocharger technology involves drawbacks such as lag. Another
disadvantage is the fuel consumption of a powerful turbocharged engine in
practice. And last but certainly not least, such an engine is far inferior to a
high-revving normal-aspiration power unit in terms of its spontaneity.

What do you mean by 'spontaneity'?

Richer: Customers interested in a sports car value an engine that responds
instantaneously- even in the smallest movement of the accelerator. The driver
wants to have the commands he gives with his right foot translated directly
into acceleration on the road- and without the slightest delay. This is
precisely what we are able to offer with our high engine speed concept. But the
proper gearing and transmission are crucial for it to work, and that is what
essentially completes the usable acceleration.

What does that mean in practice?

Richter: If you follow an analogy of riding a bicycle: When you're riding
uphill, for example, you will shift down at some point in time. This means that
you will turn the pedals more often in each unit of time but in return, you'll
are able to climb a steeper gradient faster. In cars, being in that tougher
gear going up the hill is comparable to a large-capacity engine. Being able to
shift down quickly and have the engine rev high is precisely what we were after.

How does torque come into play with the proper gearing and engine speed?

Richter: In principle high torque means a lot of thrust and good acceleration-
like big displacement engines. But torque alone does not give you sporting
performance on the road either. Rather, you once again need engine speed and a
quick response from the engine. To give you a comparison, a tractor on a farm
powered by a diesel engine may well develop up to 530 lb.-ft of torque - but
with the engine revving at a mere 1400 rpm; that tractor will obviously not
accelerate very quickly. The new M3, on the other hand, has only about half as
much torque but reaches its peak torque level at 4900 rpm and accelerates to
100 km/h in 5.2 seconds. And a Formula 1 racing car with more or less the same
torque as our M Car accelerates even faster because it reaches its peak torque
at an almost 13500 rpm.

So ultimately it's the ideal interaction of transmission ratios and high engine
speed that ensures superior performance on the road?

Richter: Exactly. The big advantage of this high engine speed concept is that
it provides maximum performance on the road with a relatively small engine,
compact axle and drive units. And then there is fuel mileage: Generally, a
large-volume V8 engine will consume more fuel than an equally powerful but more
compact straight-six. To some degree there is also a technical challenge
presented by our concept, to make the most power out of a small unit. The
challenge is what really motivates every engine designer and engine builder.

Can you explain that in greater the technical challenge and the durability
involved?

Richter: Well, the physical loads acting on our new M3 power unit are designed
around the loads you will measure in a Formula 1 engine. One similarity you
will is the significant demands of special materials. The big difference, of
course, is that a Formula 1 racing car only has to last one race, whereas a BMW
M engine must last for the entire lifecycle of the car.

Doesn't experience from the development of Formula 1 engines at BMW go into
every M engine?

Richter: Yes, there is of course a fundamental exchange of experience and
know-how in Formula 1 and the new M3. The experience in the use of high-tech
materials and high-performance electronic control unit are similar as are the
monitoring of millions of bits of data with each revolution of the crankshaft.
One factor shared by both projects and technologies is that at the end of the
day- only the team with the highest engine speed can really beat the
competition!

[ 27. April 2000 | BMW Canada Inc; Land Rover Canada | Tobias Nickel | Tel:
(001) 905 / 428-5005 | e-mail ]