The ultimate track weapon from BMW, the new M4 CSL
As its 50th birthday celebrations gather pace, BMW M GmbH is unveiling a new BMW M4 CSL, fusing old-school racing passion with innovative technology to create the ultimate performance experience. Its character is defined by a power hike of 40hp over the current BMW M4 Competition Coupé to 550hp and a host of meticulous weight-saving measures.
With years of experience in working with carbon-fiber-reinforced plastic (CFRP) for the body, chassis, and interior components, BMW M engineers have managed to restrict the special edition’s curb weight to 1,625kg (in the standard specification in the German market). As a result, the new BMW M4 CSL is 100kg lighter than the BMW M4 Competition Coupé (in the standard specification in the German market), sprinting from 0 to 62mph in 3.7 seconds, and 124mph in just 10.7 seconds – 1.8 seconds quicker than the BMW M4 Competition Coupé. The top speed is an electronically limited 190mph.
The new BMW M4 CSL has track driving as its raison d’être, its two-seater configuration and chassis set-up sharing the genes of its competition-spec sibling, the BMW M4 GT3. In tests on the Nürburgring’s Nordschleife circuit, it posted a lap time of 7:15.677 on the 12.8-mile track, with an official notarized time for the 12.943-mile circuit (the complete lap) of 7:20.207 – the best figures ever for a series-produced BMW car. Lap times aside, the new BMW M4 CSL allows drivers to enjoy an intense racing-car feeling on the road as well as on the track.
Production will begin at BMW Group Plant Dingolfing in July 2022 and is strictly limited to 1,000 units globally.
Fundamental and detailed: intelligent lightweight design in the BMW M4 CSL
Lightweight design has played a central role at BMW M GmbH from day one. In 1973 the BMW 3.0 CSL won the European Touring Car Championship at the first attempt. Today, the CSL designation stands for “Competition, Sport, Lightweight” and marks out high-performance models with particularly high output, rigorously reduced weight and a character honed purposefully for driving on the track.
Conventional components for the exterior, interior, powertrain, and chassis were replaced with lightweight model-specific alternatives. M Carbon full bucket seats reduced weight by 24kg, while 21kg was saved by removing the rear seats and belts. Chassis changes such as the use of lightweight M Carbon ceramic brakes and special light-alloy wheels, springs, and struts saved 21kg. Switching to ultra-lightweight sound insulation saved around 15kg. The use of CFRP in the body deducts 11kg, a titanium rear silencer cuts more than 4kg, and a further 4kg was saved from the BMW kidney grille, rear lights, floor mats, and climate control.
Roof, bonnet, and boot lid in carbon-fiber
The BMW M4 Competition Coupé already features a roof made from CFRP, cutting weight and lowering its center of gravity, which in turn enhances agility. The body of the BMW M4 CSL also includes the use of carbon fibre for the bonnet and boot lid.
The CFRP bonnet is approximately 1.2kg lighter than the BMW M4 Competition Coupé’s aluminum item. Its carbon-fiber structure is revealed by two unpainted, red-outlined indents extending in line with the BMW kidney grille to the edge of the bonnet. Red accent lines also emphasize the two fins on the CFRP roof and the contours of the extended side sills.
The Frozen Brooklyn Grey metallic exterior paint finish is exclusive to the BMW M4 CSL, with Alpine White and Sapphire Black also available. Classic “BMW Motorsport” emblems for the bonnet, boot lid, and wheel centers are also available, recalling the 1973 originals.
Also in CFRP are the splitters fitted to the lower edge of the front apron to generate additional downforce and the inserts in the air curtains. The splitters have red accents and “CSL” lettering. The bespoke BMW kidney grille has a stripped-back design and features red contour lines and “M4 CSL” badging, with the central air inlet subdivided by just two horizontal grille bars, saving 0.5kg.
The CFRP boot lid of the BMW M4 CSL provides a 6.7kg weight saving over the BMW M4 Competition Coupé, its carbon-fiber structure visible inside through the unpainted clearcoat. The boot lid sports a pronounced spoiler, referencing a similar feature of the 2003 BMW M3 CSL. The diffuser integrated into the rear apron and the exterior mirror caps are also made from CFRP.
BMW Laserlight: yellow headlights and innovative rear lights fitted as standard
Both in the welcome effect triggered when unlocking the doors and when the low and high beams are switched on, the BMW Laserlight headlights illuminate in yellow rather than white, bringing to mind the look of successful GT racing cars.
The rear lights of the new BMW M4 CSL use an innovative technology making its debut in a series-produced car. All light functions use LED units, while the covers have intricate light threads woven into them, illuminated using laser technology. The threads run parallel to one another before crossing over at the outer edges to create a stunning interpretation of the hallmark BMW L-shaped rear light contour. Illuminated “BMW Laser” lettering on the light covers hints at the innovative technology below the surface.
The model badges on the rear, front side panels, and BMW kidney grille also have a new design, with black surfaces and red outline.
Strut brace in the engine compartment, titanium rear silencer
In the engine compartment, an intricate cast aluminum strut brace takes the body rigidity of the new BMW M4 CSL to another level, with agility and steering precision optimized to maximum effect while minimizing material use and weight.
The new BMW M4 CSL’s rear silencer is made from titanium, cutting the weight of a conventional steel equivalent by 4.3kg. The twin tailpipes have matt black trim with a stripe-patterned perforation on its inner surface. The model-specific exhaust system comes with electronically controlled flaps, generating an intense racing aura both outside and inside the car. Gear changes are accompanied by precisely defined engine speed overshoot, while distinctive, low-frequency sound sequences can be heard on the overrun. The M Sound Control button on the center console lets the driver switch to a more restrained soundtrack when needed.
Model-specific light-alloy wheels and M Carbon ceramic brakes as standard
The forged cross-spoke M light-alloy wheels have been designed exclusively for the new BMW M4 CSL, and are fitted with track-focused 275/35 ZR19 tires at the front and 285/30 ZR20 at the rear. Alternative, more road-focused tires are available as a no-cost option.
The new BMW M4 CSL is fitted as standard with M Carbon ceramic brakes that are around 14.3kg lighter than the brakes on the BMW M4 Competition Coupé. Their red-painted calipers team up with 400mm x 38mm discs at the front and 380mm x 28mm discs at the rear. Two pedal feel settings can be selected from the M Setup menu.
Two very special seats
The lightweight coupé only has seats for the driver and front passenger, but these are no ordinary seats. The M Carbon racing bucket seats were developed exclusively for the BMW M4 CSL with the focus firmly on track driving. Their carbon-fiber structure and deliberate lack of comfort features such as heating and lumbar adjustment allowed weight to be reduced by 24kg. Their pronounced contours offer an extremely high level of lateral support and an integrated side airbag, while cut-outs enable the use of a six-point harness. The seats have a fixed backrest angle, while the seat height can only be adjusted in a workshop using a three-stage screw linkage. The forward/back adjustments can be made manually using a lever on the front edge of the seat. The head restraints can be disassembled for track use to avoid interfering with a helmet.
Trimmed in black leather with red Alcantara inserts for the outer backrest surfaces and head restraints, contrast stitching in the colors of BMW M GmbH adorn both the seat bolsters and the seat belts.
M Carbon bucket seats with enhanced comfort are available as an alternative option and are still 9.6kg lighter than the seats in the BMW M4 Competition Coupé. These optional seats combine racing functionality and lightweight design with a higher level of comfort, with electrically operated adjustment, seat heating, and an Easy-Entry function allowing easy access to the rear, where a stowage area behind the seats provides space for two helmets. Removing the rear seat cuts weight by around 21kg.
Carbon-fiber center console: reduced weight, unrestricted functionality
The center console of the new BMW M4 CSL is made entirely from CFRP, the material’s distinctive structure clearly visible around the gear selector and iDrive Controller. The use of carbon fibre more than halves the weight of the center console, a saving of around 4kg.
The new special-edition model shares the BMW M4 Competition Coupé’s signature interior design, focused entirely on performance. M-specific displays ergonomically optimized controls with red accents, the M-specific gear selector, and the anthracite-colored headliner create a racing aura even before the car has turned a wheel. Putting the finishing touches to the cockpit is the carbon-fiber interior trim strip and “CSL” badging below the head restraints, on the center console, and on the rear panel. The M Alcantara steering wheel features a red 12 o’clock marker, carbon-fiber inlays on the three spokes, and CFRP shift paddles.
Modified six-cylinder engine, eight-speed M Steptronic transmission, and rear-wheel drive for the ultimate performance experience
Modifications for the new BMW M4 CSL contribute to a maximum output of 550hp when the rev counter hits 6,250rpm – an increase of 40hp over the BMW M4 Competition Coupé. Peak torque of 650Nm is on tap from just 2,750rpm and sustained all the way up to 5,950rpm. A bespoke engine mounting and rigorous application of lightweight design principles ensure the new BMW M4 CSL achieves an even bigger gain in dynamic prowess than this extra dose of M power would suggest.
Power was boosted by increasing charge pressure at the same time as making model-specific tweaks to the engine management. Yet this potent version of the 3.0-litre engine is also extremely efficient, with WLTP-calculated fuel consumption of 28.0 – 28.8mpg and CO2 emissions of 227 – 222g/km.
A design principle focused on extracting maximum power
The straight-six engine has been adapted from racing car machinery and is focused squarely on high rev speeds and maximum power delivery. The crankcase’s sleeve-free, closed-deck construction helps to make it extremely rigid, paving the way for very high combustion pressures that optimize power output. The free-revving performance is aided by a twin-wire-arc-sprayed iron coating for the cylinder bores and the forged lightweight crankshaft, while its torsional resistance enables it to handle extremely high levels of torque.
The M-specific components also include the cylinder head with the 3D-printed core. This additive manufacturing process enables geometric forms to be created that are beyond the capability of conventional metal casting techniques. As a result, the coolant duct routing could be optimized while also reducing weight.
Two mono-scroll turbochargers supply compressed air to cylinders 1 – 3 and 4 – 6 respectively while an indirect intercooler is supplied by a low-temperature circuit and specially-designed compressors. The system operates at a maximum charge pressure upped from 1.7 to 2.1 bar. Engine management has been modified accordingly to guarantee constant power delivery up to the top end of the rev range.
Operating at a maximum pressure of 350 bar, the High Precision Injection system ensures efficient mixture preparation and clean combustion. VALVETRONIC variable valve timing and Double-VANOS fully variable camshaft timing likewise form part of the M TwinPower Turbo technology. The straight-six engine is also fitted with a particulate filter to improve emissions.
The cooling system aboard the new BMW M4 CSL comprises a high-temperature and a low-temperature circuit. The indirect intercooler works using an electric coolant pump in the low-temperature system. The main module in the high-temperature circuit and two remote coolers in the wheel arches supply coolant to the engine block and turbochargers with the help of a mechanical water pump. An electric water pump and an electric fan can also cut in when required. The large openings in the front apron additionally channel the oncoming air to an engine oil cooler and transmission oil cooler.
The oil sump has two separate chambers and an integrated suction channel. An extra suction stage allows the map-controlled oil pump to draw lubricant from the smaller chamber, which steps in when extra capacity is needed. This ensures a consistent supply of oil at all times, even under extreme lateral and longitudinal acceleration on the track.
A firmer engine mounting produces an exhilarating, highly precise sensation that is reminiscent of a racing car. The transmission mounting has also been modified.
Eight-speed M Steptronic transmission with Drivelogic
The M-specific version of the eight-speed M Steptronic transmission with Drivelogic features ratio spacing attuned to the engine’s characteristics and extremely sharp shift action. Each gear change is clearly communicated to the driver, even when the transmission is operating in automated mode. Manual shifts with sequential gear selection can be performed using either the selector lever or the carbon-fiber shift paddles. Multiple downshifts to the lowest available gear can be executed in manual mode by pulling the left shift paddle while pressing the accelerator to the floor. M Steptronic does not force upshifts under acceleration in manual mode, even when the engine’s revs hit the limiter. In automated mode, automatic engine blipping reduces engine braking when downshifting. The driver can use the Drivelogic button integrated into the selector lever to alter the shift characteristics with a choice of three clearly distinguishable modes, including a special track-optimized setting.
Chassis precision at its finest
Providing the basis for the new BMW M4 CSL’s chassis is the pairing of a double-joint spring strut front axle and five-link rear axle. Standard equipment includes adaptive M suspension with electronically controlled dampers, electromechanical M Servotronic steering with variable ratio, and an M-specific version of the integrated braking system.
Eight-millimeter drop in ride height, auxiliary springs, and bespoke dampers
The model-specific suspension features an 8mm reduction in ride height compared with the BMW M4 Competition Coupé, lowering the center of gravity. Auxiliary springs are also fitted at both the front and rear axle and improve road contact in dynamic situations. The anti-roll bars at both axles and their mountings have likewise been specially engineered.
The front axle’s forged swivel bearing has more camber, increasing the ability to put down power through high-speed corners. On the rear axle, four additional ball joints with zero play take the place of the rubber mounts for the control arms on both the axle subframe and wheel carrier sides, lowering the secondary spring rates and optimizing wheel location, camber stiffness, and damper response. The rear-axle subframe has a rigid bolted connection to the body without any flexible rubber elements, improving directional stability.
Damping forces for each wheel are adjusted in a few milliseconds using electromagnetic valves to suit the changing conditions. There are three modes in the M Setup menu: SPORT was fine-tuned during exhaustive testing at the Nordschleife. SPORT PLUS is designed for perfectly surfaced race tracks, while COMFORT is ideal for everyday driving.
M Traction Control honed for the track
The inclusion of the integrated braking system enables the DSC (Dynamic Stability Control) system to intervene more swiftly and precisely than ever. Traction control duties have also been relocated from the DSC control unit to the engine management, allowing the engine’s power to be adjusted with exceptional sensitivity when accelerating on slippery surfaces.
The new BMW M4 CSL lets the driver set individual intervention thresholds for wheel slip in ten different stages, with the option of deactivating DSC by engaging M Dynamic Mode. M Traction Control stages 1 to 5 are the same as in the BMW M4 Competition Coupé, while stages 6 to 10 have been devised for track conditions and are geared towards optimizing traction to deliver quick lap times.
Two-seater with exclusive sports car cockpit
The M Carbon full bucket seats, M Alcantara steering wheel, and M-specific control panel on a center console hewn from CFRP create the perfect setting for driving pleasure. Standard equipment includes Merino leather with extended features and M seat belts with contrast stitching in the colors of BMW M GmbH.
The CSL model badge is displayed in the information display of the standard BMW Live Cockpit Professional, comprising a 12.3-inch instrument cluster and a 10.25-inch control display. The interaction between the driver and vehicle can take place via touch control on the controlled display, the iDrive Controller, the multifunction buttons on the steering wheel or voice control. BMW Live Cockpit Professional also includes the BMW Intelligent Personal Assistant, cloud-based navigation system BMW Maps, telephony with wireless charging, smartphone integration enabling the use of Apple CarPlay and Android Auto, two USB ports for data transfer, a Wi-Fi interface, and numerous advanced digital services. Standard equipment also includes a 10-speaker HiFi system with a 205-watt amplifier.
The BMW Head-Up Display is available as an option for the new BMW M4 CSL as part of the Ultimate Road Pack, supporting the driver to focus on the task at hand by projecting relevant information onto the windscreen. It includes M-specific elements such as a color rev counter, Shift Lights, and M View. In addition, the Ultimate Road Pack for the M4 CSL also includes Comfort Access, Driving Assistant, Parking Assistant, Folding Wing Mirrors with automatic dimming, and Wireless mobile phone charging.
Comfort-enhancing features and assistance systems focused on the essentials
The lightweight design of the new BMW M4 CSL means the onboard systems are focused on the essentials for track driving. Driving Assistant, which includes Lane Departure Warning, Speed Limit Info, and Front Collision Warning with brake intervention can be selected via the optional Ultimate Road Pack.
Individually configurable vehicle settings
The Setup button on the center console provides direct access to the configuration options for the engine, shock absorbers, steering, and braking system. Two individually composed variants of the M Setup can be stored with the driver’s settings for the engine sound, M Traction Control, Automatic Start/Stop function, and the gearshift characteristics. The configuration can then be recalled by pressing one of the two red M buttons on the steering wheel.
M Drive Professional and M Mode button
The standard M Drive Professional helps the driver to make improvements in their pursuit of the ideal line and faster lap times. For example, dramatic use of oversteer and opposite lock is recorded by the M Drift Analyser, while a steering-on-the-throttle performance rating comprises a mark between one and five stars with a comparison against the driver’s previous best. An overall view also displays the number of drifts recorded, the distance covered while sideways, and other facts and figures.
The M Laptimer, meanwhile, sends a variety of information to both the instrument cluster and the BMW Head-Up Display. This allows the driver to keep an eye on how much quicker they are than their current fastest lap. The display shows the number of laps completed so far, the distance covered, and the duration of the current stint. Drivers can also analyze the data in detail with the BMW M Laptimer iPhone app and share it with the online community.
The M Mode button can be used to adjust the responses of the various systems, with the usual ROAD and SPORT modes joined by a TRACK mode. In SPORT mode, the instrument cluster and Head-Up Display switch to M View, which only presents information relevant to sporty driving such as an M-specific rev dial and Shift Lights, digital speed read-out, and gear indication. Data including coolant temperature, charge pressure, tire condition, and lateral and longitudinal acceleration can be displayed in the side areas of the instrument cluster.
TRACK mode is activated by an extended press of the M Mode button and confirmed using the iDrive Controller. This setting deactivates all comfort and safety functions of the driver assistance systems, the controlled display is switched off to focus the driver’s attention, and the instrument cluster and Head-Up Display switch to M View, with road sign detection also hidden.