BMW announces M3 & M4 details [Release]
Fri, 12/20/2013 - 11:23 — admin
BMW M engineers have paid particular attention to the car’s aerodynamic performance, and incorporated the latest Active M Differential amongst numerous other technical highlights. During the development process the engineers worked closely with BMW Motorsport’s professional racing drivers, with extensive testing and set-up work carried out on the Nürburgring Nordschleife circuit.
Model Power (hp) Torque (Nm) 0-62mph (secs) Top speed (mph) Combined (mpg) CO2 emissions (g/km)
The Aero Curtain and M side gills, the latter with integrated Air Breathers minimise turbulence in the front wheel arches. These elements, together with the aerodynamically optimised side mirrors in familiar M twin-stalk style, are not only distinctive design features, they also help to reduce drag.
The new BMW M3 Saloon and new BMW M4 Coupé mark a return to the classic six-cylinder in-line engine configuration, as used on the second and third-generatios of this iconic sports car.
The new engine sees a slight power upgrade over the previous V8 to 431hp, now delivered between 5,500 and 7,300rpm, with maximum revolutions set at an unusually high figure for a turbocharged engine: 7,600rpm. Peak torque has been increased by roughly 40 per cent to 550Nm, and is maintained over a very wide rev range (1,850–5,500rpm). The standard sprint from 0-62mph takes both cars just 4.3 seconds with manual transmission, or just 4.1 seconds with the optional M DCT, while the top speed is 155mph (electronically limited). The new powerplant also boasts excellent fuel economy: the combined consumption in the EU cycle is as high as 34mpg and CO2 emissions are as low as 194g/km, an improvement of more than 25 per cent over the previous model’s figures. Regulated pollutant emissions are EU6-compliant.
The M Twin Power Turbo technology comprises two fast-responding mono- scroll turbochargers, High-precision direct injection, VALVETRONIC variable valve timing and Double-VANOS continuously variable camshaft timing. VALVETRONIC and Double-VANOS work in tandem to seamlessly control intake valve lift. The result is a smooth and efficient power delivery, with very sharp response and reduced fuel consumption and emissions.
The six-cylinder engine features a closed-deck crankcase design, which is very rigid and allows cylinder pressures to be increased for improved power output. And instead of liners, the cylinder bores feature a twin-wire arc- sprayed coating, which results in a significant reduction in engine weight.
A further technical highlight is the forged, torsionally rigid crankshaft which, as well as providing increased torque-carrying capacity, is also lighter in weight. This significantly reduces rotating masses, resulting in improved throttle response and acceleration.
A sporting engine sound, in keeping with BMW M tradition, is ensured thanks to the lofty rev range of the new engine and an innovative flap arrangement in the twin-pipe exhaust system. The electrically-controlled flaps just before the rear silencer minimise exhaust backpressure and produce a sound that is striking and unmistakable over the entire engine speed range, as well as giving precise feedback on engine load.
The different selectable drive modes, programmable with the MDrive Manager and activated via the iconic steering wheel ‘M’ buttons, offer drivers a choice of preconfigured, perfectly balanced vehicle set-ups which also feature different engine sound profiles.
Track-ready engine oil supply system for outstanding performance
Sophisticated cooling concept for maximum performance
For example, alongside the two sophisticated turbocharger units, the air intake system of the six-cylinder engine also includes an indirect intercooler, maximising charge pressure and engine output. Moreover, as well as a main radiator, the cooling system also comprises a water cooler repositioned to the side for the high and low temperature water circuits, and the engine and transmission oil (if the M Double Clutch Transmission is specified). An additional electric coolant pump cools the turbocharger bearing mounts when the car is stationary.
Six-speed manual gearbox with new throttle blipping function:
Seven-speed M Double Clutch Transmission with Drivelogic and Launch Control
Taking advantage of the extremely light yet impressively durable properties of CFRP (carbon-fibre reinforced plastic), the engineers have been able to construct the driveshaft from this material.
“The impressive stiffness and low weight of the CFRP tubing allow the driveshaft to be constructed as a single-piece unit with no centre bearing. As well as a weight-saving of 40 per cent over its predecessor, we have achieved a reduction in rotating masses and therefore improved drivetrain dynamics.” explains Albert Biermann.
The rear-wheel drive chassis with Active M Differential
Every driving situation is therefore precisely analysed and an impending loss of traction on one side of the car identified at an early stage. The degree of differential lock – which may be anywhere between 0 and 100 per cent – is adjusted as required within a fraction of a second, enabling wheel spin to be prevented on slippery surfaces, in instances where the right and left rear wheel have widely differing friction coefficients or in tight bends and when changing direction with particular vigour.
The M Dynamic Mode – a sub-function of the Dynamic Stability Control (DSC) system – allows enthusiastic drivers to probe the limits of the new cars while retaining an electronic safety net at all times. The system tolerates greater wheel slip and therefore easy drifting, although DSC will still step in if the car ventures over the limits – unless it is switched off completely.
Aluminium suspension elements ensure sharper dynamics
In the front suspension the use of lightweight aluminium construction for components such as control arms, wheel carriers and axle subframes saves 5kgs over a conventional steel design. Play-free ball joints and elastomer bearings developed specially for the cars ensure an optimum and direct transfer of forces both laterally and longitudinally, while an aluminium stiffening plate, CFRP engine strut brace and additional bolted joints between the axle subframe and the body structure all help to increase the rigidity of the front end.
Also lighter is the new five-link rear axle. All the control arms and wheel carriers are manufactured using forged aluminium, which reduces the unsprung masses of the wheel-locating components by around 3kgs compared with the previous model generation. The rigid connection between the rear axle subframe and the body – without the use of elastic rubber elements – is borrowed from motorsport and serves to further improve wheel location and therefore directional stability.
Tyre development was critical from the outset, and both cars feature 19-inch wheels as standard for the UK market, in either Ferric Grey or optionally Jet Black. These specially developed forged wheels make a significant contribution to the reduction in the cars’ unsprung masses. BMW M engineers have taken great care to ensure all the components between the steering wheel and tyres work together harmoniously and therefore provide maximum driving precision and lateral stability, while retaining good ride comfort.
Electric Power Steering with three settings
The Adaptive M suspension, fitted as standard for the UK market, also provides COMFORT, SPORT and SPORT+ modes, enabling the driver to choose between a more comfortable damper setting for urban driving, for example, or a stiffer set-up for dynamic driving on country roads. A third option minimises body movements and maximises dynamic performance for use on the track.
The standard new BMW M Compound brakes boast impressive feel, outstanding stopping power and a high resistance to fade. Far lighter than conventional equivalents, they contribute to a substantial reduction in unsprung masses. Even lighter BMW M Carbon ceramic brakes can be specified as an option - gold callipers denote their fitment.
Lightweight engineering: shedding weight in all the right places.
On the outgoing models, the CFRP roof was confined to the Coupé version. Now, for the first time, the four-door BMW M3 Saloon gets this striking design and functional feature as standard. The CFRP roof brings weight-savings of 5kgs in the case of the BMW M3 Saloon and more than 6kgs in the case of the BMW M4 Coupé. It also lowers the vehicle’s centre of gravity, which has a positive impact on driving dynamics.
Aluminium is used for the front wings and the bonnet, as opposed to conventional steel, and makes an important contribution to the low overall weight, while at the same time improving axle load distribution.
On the M4 Coupé, the shape of the new bootlid has been optimised for aerodynamic performance, while the use of a carbon-fibre and plastic compound saves additional weight.
The new BMW M3 Saloon and new BMW M4 Coupé also feature a CFRP driveshaft. The high rigidity and low weight of the CFRP tube mean that the driveshaft can be produced as a single-piece component, without a centre bearing. This achieves weight-savings of 40 per cent over the previous model and a reduction in rotating masses, which in turn results in more dynamic powertrain response.
A further use of CFRP can be found in the engine compartment for the engine strut brace. Weighing only 1.5kgs it offers superior rigidity to a comparable aluminium component, and at the same time plays a key part in the excellent steering response and precision of both vehicles. The use of carbon-fibre in these models is a reminder that BMW is a global leader in high-strength, lightweight CFRP construction, and that it was BMW who brought out the first mass-production vehicle with a body consisting entirely of this material – the innovative BMW i3.
Design: striking use of forms underlines standout performance capability.
Viewed from the front, the BMW M3 Saloon and BMW M4 Coupé have a powerfully expressive ‘face’, with a modern take on the twin headlight arrangement and a distinctive double-slat kidney grille with M designation. The aggressive front apron, with its trio of large intakes, supplies cooling air to the engine and brakes. Among the other hallmark BMW M design features is the characteristic powerdome on the bonnet, which hints at the potential of the muscular M TwinPower Turbo engine and creates space for the intercooler. The twin-stalk side mirrors are another classic BMW M design feature.
The sides of both cars clearly show the hallmark BMW proportions of a long bonnet, long wheelbase, set back glasshouse and short front overhang, further emphasised by familiar M design elements. The new M side gills perform both a stylistic and a functional role: integrated into them are Air Breathers, which team up with the Aero Curtains in the front apron to help optimise the airflow around the wheel arches and therefore improve aerodynamics.
The dark colour of the CFRP roof (with its contoured roofline) gives both models a lower-slung and more compact appearance, as the eye perceives the roof pillars – painted in body colour – to be the uppermost point of the car. A flowing roofline then gains in momentum once again as it heads rearwards, increasing aerodynamic downforce and giving the rear a more muscular look at the same time.
At the rear, there are greater differences in the two models. The BMW M3 Saloon is fitted with a lip spoiler to reduce lift, while the tailgate of the BMW M4 Coupé features an integrated rear spoiler and is made from a carbon-fibre compound.
Both models feature prominently flared rear wheel arches, which, in combination with the wide track, give the cars a very purposeful stance. The high-gloss pair of twin exhaust tailpipes are framed by the sculptural rear apron with its integrated diffuser.
Interior design: flawless ergonomics in a sporting ambience.
The bespoke front seats take inspiration from the bucket seats fitted in racing cars, and feature a full-size single-piece back panel. This means the construction of the seats is very flat, while the high, width-adjustable side bolsters and low-set seat surface allow an ideal seating position and provide excellent support. Despite this, these BMW M seats also include electric adjustment and heating as standard. On the seat surface, the stitching, upholstery segmentation and perforation lend the seats a slim-fitting feel, whilst the BMW M logo on the seat is illuminated for the first time.
Like the front seats, the distinctively contoured backrests of the rear seats also offer exceptional lateral support: they are made from a lightweight composite material and can be folded in a 60:40 split. This gives the BMW M3 and BMW M4 a level of everyday usability that is well beyond the norm for high-performance sports cars.
Equipment: extensive standard equipment joined by a host of options that enhance dynamics and comfort.
In addition, customers can choose from a broad range of optional equipment to give the cars either an additional sporting edge, or boost comfort levels further still. For those buyers wishing to personalise their cars yet further, the wide-reaching spectrum of BMW Individual – including BMW Individual paint finishes, BMW Individual Merino leather and BMW Individual interior trim elements – will be available later in 2014.
Further options for comprehensive driver information
Naturally, the BMW M3 Saloon and BMW M4 Coupé are also available with the wide variety of driver assistance systems and mobility services introduced under the BMW ConnectedDrive banner, some of which will already be familiar from the BMW 3 Series and BMW 4 Series. Among the highlights are the latest-generation of the Professional Navigation system, offering extra capability, sharper graphics and 3D elements for the map display; Driving Assistant Plus, which warns the driver of a looming collision with a pedestrian; Adaptive full LED headlights with an intelligent anti-dazzle High-beam Assistant and a further developed version of Active Cruise Control with Stop & Go function.
The optional M Head-up Display comes with additional, M-specific functions such as a gear display, rev counter and Optimum Shift Indicator.
Production: return to the birthplace of the BMW M3.
The first-generation BMW M3 exceeded all sales expectations: including the Convertible variant, the various evolution stages of the car and the special-edition models, BMW sold a total of 17,970 M3s worldwide by the time production ceased in 1991.
In 1997 the BMW M3 became the world’s first volume-produced car to be available with a Sequential M Gearbox (SMG). This transmission was based on the conventional gearbox for the M3, but with a clutch that was activated electro-hydraulically. 71,242 units of the Coupé, Convertible and Saloon combined were produced at Plant Regensburg.
The pinnacle of this generation was the BMW M3 CSL, introduced in 2003. The suffix stood for “Coupé Sport Lightweight”, justified by elements such as a carbon-fibre roof, centre console and door panels, a lighter rear window and the omission of numerous comfort-oriented features. With a kerb weight of just 1,385kgs, it weighed 110kgs below the standard M3. All 1,383 units of the 360hp vehicle were sold within just a few months.
Highlights during the production run included the BMW M3 GTS, which contained a larger 4.4-litre V8 to produce a peak output of 450hp. The GTS featured specially developed chassis components and aerodynamic measures, plus a two-seat cockpit conceived for track use. Only available with Fire Orange paintwork, the GTS was aimed specifically at circuit driving as well as road use. Just 135 examples of this model were delivered to customers, with just 15 coming to the UK.