CompleteCar

Riding shotgun in the 2014 BMW M4 Coupé

Riding shotgun in the 2014 BMW M4 Coupé

Published on September 25, 2013

There's arguably no bigger news for either BMW or performance car fans than the announcement of a new M3 - and the fifth generation of this heroic machine is on its way, although the Coupé version will actually be called the M4. We have a sneak preview of the two cars' technology ahead of a proposed July 2014 launch, before being taken for a rapid passenger ride in a prototype.

In the Metal:


The three prototypes on hand at Munich, one M3 and two M4s, were all heavily disguised. However, resplendent on a stand next to the main building was the M4 Concept vehicle as shown at the Pebble Beach Concours d'Elegance in August, and apparently this is pretty much how the finished article will look. The good news is it is sensational, with scarcely a bad angle to it (although the ramrod-straight leading shut line of the bonnet somehow looks a bit odd amid all the curves and bulges), and the only problem I can foresee is that this supremely elegant yet muscular Coupé will never get to wear the hallowed M3 badge. That belongs solely to the four-door saloon, a car that seemed to be curiously overlooked during all of our presentations at Maisach.

Inside is a long way from being confirmed and the three prototypes were in a fairly rough'n'ready state with few clues as to the production versions' cabins. Grey dials were on show, as was a chunky, three-spoke steering wheel, but the front seats were just placeholders for the time being. The standard 4 Series Coupé is a comfortable four-seater and there's no reason to doubt the M version will be any less accommodating.

Driving it:


First, the good points. We hitched a ride in a pre-production M4, driven by up-and-coming DTM star Dirk Werner, and the high-speed stability of the M Coupé is astonishing. Even from the passenger seat, its rigid body control and ability to change direction at faintly ludicrous velocity is exceptional for a rear-wheel drive vehicle. Through fast sweepers and tighter bends the M4 could carry much higher speeds than even the most ardent M Division fan could have predicted.

It's not boringly benign, though, Werner confirming that both the front and back ends are lively and part of proceedings. You might not be able to steer it on the throttle as readily as the old V8 predecessor, but there was certainly a sense of both the front and back moving around on the Maisach circuit. Werner also said the steering was superb, but on that score we'll obviously have to reserve judgment for now. The body control and ride seemed firm without being uncomfortable, while the brakes were plenty powerful enough on track.

Less emphatic were the noise and the pace of the M4. From the outside, regrettably this is one of the dullest sounding M Coupés yet, with a flat exhaust blare and no real mechanical overtones from the six-pot. Strangely, from the inside it sounds better - you'd think the induction noise in the cabin would be muted by the twin turbos, but that's not the case. In fact, on initial acceleration it's eerily reminiscent of the old straight-six S54 from the E46 M3, which is clearly a very good thing. Where it lets you down is in the final, upper rpm ranges; there's never any moment where the roar of the S55 becomes spine-tingling. This is a great shame, as the S14, S50, S54 and S65 lumps that have preceded it have all been aural delights in one way or another.

The outright pace of the M4 is hard to determine. With its massive torque plateau, 430hp and a target kerb weight of less than 1,500kg, it should feel ballistic compared to its already-rapid forebear - especially when you're only a passenger and there's a DTM driver giving it ten-tenths behind the wheel. However, the M4 didn't feel as quick as I was expecting in a straight line. Whether the airfield setting was diminishing the visual sense of speed or not, the big kick in the back I was anticipating from in excess of 500Nm never really made itself felt. The power delivery was linear, but a bit anodyne too.

What you get for your Money:

Exact specs are a long way from being finalised but this was a showcase for the cars' tech, so let's look at that. Some good news for M fans is the M3/M4 will be returning to a straight-six, in this instance an all-new unit codenamed S55 B30. This is adorned with two turbochargers and a top-mounted, water-cooled intercooler, which sits under the bonnet's 'Power Dome', a feature of M3s since the E46. The engine is equipped with an exhaust system that leads to the traditional M quad-piped muffler at the rear. There's a clever electronically-controlled flap in the exhaust that channels air straight through the back-box under heavy loads for a 'more sporty' noise; at other times, there's a cross-flow going on, with gases from the right-hand branch exiting the left-hand tailpipes and vice versa.

In terms of motive power, every effort has been made throughout the entire induction, combustion and exhaust process to smooth the flow of air/gases and improve the efficiency and power of the engine. Stats quoted so far are 430hp at 7,300rpm, against an expected 7,500rpm redline, and a huge torque plateau from "below 2,000rpm until above 5,000rpm". Peak torque has not been pegged as yet but officials kept repeating the phrase "well in excess of 500Nm", which compares favourably with its predecessor's peak of 400Nm at 3,900rpm. Bizarrely, we were shown a graph of the torque and power curves of the E92 M3 versus the new models - but there were no markings on the X and Y axis with which to put this data into perspective. All we can say is that the F80/F82 curves were always above the E92 data.

This engine, which features Valvetronic, double Vanos, direct injection, a closed-deck crankcase, a forged crankshaft and cylinders canted over at 30 degrees; weighs 10kg less than the V8 of the predecessor and will put its power to the rear wheels via a six-speed manual gearbox (again, 10kg lighter than the V8's unit), developed from the item found in the 1 Series M Coupé. That's right, a manual gearbox will be standard. Thank the Lord. A third-generation, seven-speed DCT dual clutch shifter will be an option, with Comfort, Sport and Sport+ modes. There's an Active M Differential at the rear, this time with an electric actuator to vary the locking effect, and racetrack-inspired oil supply and cooling systems ensure the Ms will be capable of tough circuit work.

Brake discs will be steel as standard, gripped by four-pot calipers front and two-pots at rear, but opt for optional carbon brakes and these go up to six- and four-pot respectively. All disc sizes were not confirmed but M Engineering Vice-President Albert Biermann did at least yield the nugget that the carbon front discs would be a massive 400mm in diameter.

Carbon fibre reinforced plastic (CFRP) will be used extensively during production and BMW chiefs on hand constantly referred to 'light weight' and 'drivetrain rigidity' as key principles in the development of the cars. CFRP can be found in the roof (in a first, the M3 Saloon will get this feature - it has previously only been found on Coupé and Gran Coupé M cars), the boot lids with integrated spoilers harking back to the M3 CSL's ducktail affair, the roof-supporting bow that is an integral part of the body-in-white (a CFRP bow is a first for any BMW), a CFRP propshaft and a boomerang-shaped CFRP front strut brace. At a rough guess, M3/M4 Engineering Project Manager Michael Wimbeck said the CFRP components saved 20-25kg between them.

Drivetrain and chassis rigidity highlights include that forged crankshaft for a more responsive engine, with forged aluminium components scattered everywhere in the ball-jointed suspension and a rear axle carrier on both M3 and M4 that is bolted directly to the chassis, with no rubber bushing at all. This precludes lateral movement and ensures more surefooted handling.

Unsprung and rotating masses have also been targeted, an example being the forged aluminium alloy wheels weighing 6kg less overall than a set of E92 rims. And finally, the M3/M4 will feature electromechanical power steering, geared for sharpness and feedback - we hope!

Worth Noting

With current market demand meaning the growing trend of downsizing and turbocharging is the only way for manufacturers to get equivalent or better power figures from new models, it was inevitable that M Division would follow suit - and we've already had the 1 Series M Coupé, X5 and X6 M models and of course the M5s and M6s with their forced induction V8s. However, the M3 has a long normally-aspirated heritage and it remains to be seen whether buyers prefer its broader, more accessible performance in the absence of any particular high-end fireworks.

Summary

Overall, at this stage we're a little underwhelmed - sorry, BMW. There's no doubt the new M3/M4 twins will comfortably outperform their predecessors in every conceivable way, especially when it comes to very high speed cornering, and there's also a planned sub-200g/km CO2 figure to consider, which for a 430hp petrol six is black magic of the highest order. But, to be honest, we're not sure why M Division was pushing this so heavily, as surely mpg and CO2 are not the prime considerations of an M4 buyer.

And that sop to the green brigade feels like it might have taken some of the focus out of the M4. At this stage, it doesn't seem as vocal or visceral as its predecessor, and there's a fear it may just be a bit too refined and grown up - kind of an E36 M3 for the present day; much faster than its forebear, but not as enjoyable. Of course, we'll know more when we finally get the chance to have a go behind the wheel, and the on-sale date is a fair way off just yet, so expect further refinements and tweaks in the meantime that will make the M3/M4 twins' drool-inducing on-paper spec translate into a truly entertaining road machine. Here's hoping.