Part 3 : 25th Anniversary of the BMW M3 (E46)

The third M3: high performance and precision in exciting design.

Read Motor Prime's first drive of the BMW E46 M3 Coupe HERE
Read Motor Prime's re-visit of the BMW E46 M3 Coupe HERE

The community of aficionados of the M3 didn’t have to wait long. The next M3 gave lots of scope for discussion when it was unveiled as a show car at the Frankfurt Motor Show in September 1999. Six months later, it celebrated a world premiere at the Geneva Motor Show.

The third M3 was very powerful, wide and yet elegant. Thanks to a special front apron with integrated fog lamps and large cooling air intakes, it presented a significantly different profile to all other models in the BMW 3 Series. The engine compartment lid made of aluminium was curved in the centre, forming a power dome to create space for the M3 engine.

The side profile of the M3 body including the wheel arches had undergone an increase in width of 20mm, with air intakes and M3 badge in the front side panels. This beefy appearance was a visible consequence of aerodynamic optimization and an attribute creating a profile distinct from that of the 3 Series coupé. It was accompanied by appropriately beefy wide wheels in the format 225/45 ZR 18 at the front and 255/40 ZR 18 at the rear.

The impressive visual appearance of the M high-performance athlete was underscored by aspherical M outside mirrors, side sill trims and an aerodynamically optimised rear apron with rear spoiler lip. Any driver who was still unaware of which car had overtaken them was left in no doubt when they saw the four tailpipes of the twin-chamber exhaust system that it was a member of the M family of automobiles.

Sports seats developed in-house with outstanding ergonomic characteristics provided an impressive combination of lateral support and unrestricted capability for travelling long distances. Apart from the diverse electrical adjustment options at all levels, adjustment of the reclining width was also supplied as a special.

New six-cylinder with more power and torque.
People had expected no less. The heart of the new M3 was again an inline six-cylinder engine – the classic BMW power unit. Like its predecessor, this completely new engine offered lots of torque, even more power and all this for relatively low petrol consumption and low exhaust values.

The M3 engine generated the impressive power of 343 hp (252 kW) from displacement of precisely 3246cc at an engine speed of 7900 rpm. The maximum torque achieved 365Nm at 4900 rpm. This yields a specific power of 105 hp for every litre, a value that has only been achieved by a few high-performance sports cars in the world not fitted with a turbocharger.

The highlights of the engine included a friction optimised cylinder head with cam follower valve timing. The double VANOS variable timing familiar from the other M models was further optimised. Electronic throttle valve control was responsible for actuating the six individual throttle valves.

It communicated directly with the MSS 54 engine control unit specially developed for the M3. This multiprocessor system has two 32 bit microcontrollers and two timing coprocessors and computing power of 25 million calculations per second.

However, the main goal of developing the new M3 engine was not geared simply to the generation of torque at all costs. The primary objective was to generate thrust as an indication of optimum handling of the available potential power. Thrust is mainly based on the exceptionally high torque of this engine combined with a relatively short final drive ratio.

The available power could be converted into acceleration much more efficiently than in engines rotating at a lower speed. And this held over the entire range of speeds. In addition, the radial force-controlled oil siphoning guaranteed reliable lubrication and cooling for the engine in journeys with hairpin bends and manoeuvres involving heavy braking.

A few more statistics provide an indication of the athletic performance: The M3 accelerates from a standing start to 100 km/h in just 5.2 seconds. It took this car just 5.4 seconds to accelerate from 80 to 120 km/h in fourth gear.

A special switch, the M Driving Dynamic Control, also allows drivers to select between sporty and high-comfort engine response.

World first for the M3: variable M differential lock.
This sophisticated but powerful performance curve can be  effortlessly transferred to the road with the six-speed manual gearshift. The variable M differential lock being used for the first time in the M3 provided efficient support.

Differential locks can distribute different levels of tractive force individually to the rear drive wheels, depending on which wheel currently has the best traction. The special feature of the variable M differential lock was that it recorded the different rotational speeds rather than the different torque of the left-hand and right-hand rear wheels as in conventional systems.

The difference in rotational speeds was compensated by the limited-slip system containing viscose oil so that adequate forward thrust was provided. This system provided a locking effect from 0 to 100 per cent.

This offered the M3 driver tangible benefits when starting off from difficult situations, and on sporty driving round hairpin bends. The M sports chassis of the M3 was put to the test many times in international motor sport and underwent further development. The chassis ensured outstanding roadholding and this automobile was also defending the endorsement of “Best Handling Car”.

The engineers at BMW M implemented a lot of ideas to ensure that the car was capable of rising to the challenge of all types of handling limits: a high level of stiffness and minimising of the unsprung suspension components combined with a directness in performance unrivalled in this class.

Lots of power also demanded excellent braking force. That’s why the M3 was given a robust  high-performance braking system with floating compound brakes and perforated brake discs.

A revelation: the M3 Convertible.

(Read about Motor Prime's review of the E46 M3 Convertible HERE)

The new M3 Coupé had hardly been launched successfully when a second attractive version was making waves: the new M3 Convertible, an open-top sports four-seater in the premium class was launched on the marketplace in spring of 2001.

Although this car was identical with the M3 Coupé down to the A-pillar, it exuded a high level of independence. The distinctive belt line and the character of a convertible made the car appear even wider and more powerful, the overall impression conveyed by the M3 Convertible was more muscular, flatter and broader.

Naturally, all the typical M  characteristics were integrated within the M3 Convertible, such as a powerful 343 PS/252 kW high-revving naturally aspirated engine, a perfectly tuned M chassis, the variable M differential lock, M high-performance brakes and the independent M design elements with the familiar qualities of the 3 Series Convertible.

Other features included sports seats with power adjustment and integrated seat-belt system, as well as a variable folding-top compartment and a high level of safety achieved through maximally rigid body stiffness and a standard rollover protection system. The interior atmosphere was even more luxurious than the previous model – already a major success in a small niche market.

And the M3 Convertible with its top speed of 250 km/h had awesome power. It took just 5.5 seconds for it to sprint from a standing start to 100 km/h, and required only 5.9 seconds to accelerate from 80 to 120 km/h in fourth gear. Average consumption was just 12.1L for every 100km.

US racer M3 GTR: the most powerful M3 ever.
Meanwhile, quite a different M3 was creating a sensation in the USA. In 2001, the first starting flag came down for the new BMW M3 GTR with a 450 hp V8 engine. The most powerful M3 ever was now setting benchmarks in the GT class of the American Le Mans Series (ALMS) with its 4L engine and with four cars competing in the series.

The BMW Motorsport Team entered two cars under the management of Charly Lamm, while the American BMW Team PTG run by Tom Milner – who is of German extraction – entered another two cars.

The coupé achieved seven wins in ten races with six pole positions. BMW works driver Jörg Müller won the Drivers’ Championship in the GT Class, BMW Motorsport took victory in the team placings, and BMW won the Manufacturers’ Championship in the company’s most important foreign market.

Starting in February 2002, the road sports car – derated from 330 kW/450 hp to 258 kW/350 hp – could also be purchased at a price of some 250,000 euros. The engineering of the civilian version was closely based on the racing version.

A V8 high-performance engine with dry sump engineering provided the power unit under the engine compartment lid with additional cooling slits. A six-speed manual gearbox was also onboard, together with a double-disc clutch like the clutch used in the racing car.

The body was also similar to the racing version. The roof, rear wing, and front and rear aprons were made of carbon-fibre reinforced plastic to save weight.

Second generation of the Sequential M Gearbox: paddles on the steering wheel.
The advanced development of the M3 idea was by no means at an end. The next highlight followed within a few months, just as dynamically as the cars themselves. The Sequential M Gearbox (SMG) that had achieved the perfection level of the second generation in the M3.

Paddles on the steering wheel activated the SMG to change gear at lightning speed. And the driver could keep the accelerator pedal floored. The latest engine electronics interrupted the power of the engine for milliseconds, the control unit changed gear and opened and closed the clutch through an automated hydraulic system.

This second generation of the SMG gearbox also provided an impressive performance with even shorter power interruptions – now the time for the fastest gearshifts was just 80 milliseconds. Virtually, nobody can change gear that quickly using a manual gearshift.

Drivelogic also provided M3 drivers with the option of manual dynamic gearshift in six different programs to match their driving style in the sequential gearbox – from well-balanced dynamic shift to definitively sporty.

Moreover, the S6 driving program could be selected if the DSC System (Dynamic Stability Control) supplied as standard in the M3 was switched off. The SMG then changed gear with gearshift times of a sporty thoroughbred similar to a racing car.

M3 CSL: the 110 percent car.
In 2003, BMW launched the series version of a concept car on the market which had already created a sensation at the Frankfurt Motor Show in 2001: the BMW M3 CSL. The initials stood for Coupé, Sport and Lightweight.

A tradition that went back to the 1930s at BMW, when the legendary BMW 328 Mille Miglia Touring Coupé came into being. The focus for the design of this vehicle was not a radical slimming regime consisting of removing individual components, but intelligent weight reduction by using the most suitable materials at the right point.

The experts managed to slim down the BMW M3 by more than 110kg so that the CSL version weighed in at just 1,385kg. The engine was also revised and generated 256 kW/360 hp in this version. This resulted in a power-to-weight ratio of only 3.85kg to every 1 hp – a truly sensation value that gave the BMW M3 CSL even more agility than the standard BMW M3.

The classic sprint from a standing start to 100 km/h was achieved in just 4.9 seconds. Acceleration from zero to 200 km/h only took 16.8 seconds. The top speed was limited electronically to 250 km/h.

M Track Mode.
The M Track Mode was a special treat for ambitious drivers with motorsport aspirations. This function of Dynamic Stability Control (DSC) was specially tailored to driving on race tracks and had to be deliberately activated by the driver pressing a button on the steering wheel.

The system only intervened when the car was being driven to the very limit. In this way, the M Track Mode allowed ambitious lay drivers to take corners safely at the physical limits.

Innovative materials at the right point.
The intelligent lightweight construction of the M3 CSL exerted a particularly significant effect with the roof manufactured in carbon-fibre reinforced plastic (CRP) to create a striking visual profile. This large component was manufactured by specialists at the BMW plant in Landshut.

Not only was it around 6kg lighter than a conventional roof. Its exposed position also reduced the centre of gravity of the car. The BMW M engineers put virtually every component in the M3 through a weight test and integrated each component using the most suitable materials geared to saving weight.

Even glass-fibre reinforced plastics from aerospace were used for the M3 CSL; for example the thermoplastic composite for the structure of the through-loading compartment and the rear bumper mount. Or the honeycomb sandwich panel for the under-boot floor – like the M3, the M3 CSL has an engine compartment lid made of aluminium while the rear window is made of thin glass.

2004 and 2005: the M3 GTR dominates on the Nürburgring.
Eleven years after the first BMW M3 GTR drove to victory in Europe, the new-generation M3 GTR lined up on the starting grid in 2009. Two each of these racing cars fitted with eight-cylinder engines lined up on the starting grid for the 24 Hour Race in Spa-Francorchamps, Belgium, and on the Nurbürgring. The result was a class victory in Belgium and twin one-two victories at the legendary racing track in the Eifel.

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