► We drive the BMW M4 Moto GP Safety Car
► First time testing new water injection system
► CAR magazine drives it first
Retrofitted adrenalin. That’s what the rear bumper sticker on the BMW M4 Moto GP Safety Car promises. And if our first encounter with the car is anything to go by, that’s exactly what it will deliver when it becomes the top-of-the-line M4 GTS road car in 2016, complete with BMW’s innovative water-injection (WI) technology.
According to Frank van Meel, the recently appointed head of BMW M division, WI is a means to improve performance as well as fuel economy. With WI fitted, the power output of the twin-turbo 3.0-litre straight-six increases from 425bhp to at least 500, while maximum torque climbs from 406lb ft to 442 at an unchanged 1850-5500rpm. There’s only one production-ready prototype of the M4 GTS in existence – this MotoGP safety car – so we’ve come to Qatar’s scorching Losail Circuit on GP weekend to put it to the test…
The story behind BMW's Moto GP role
The safety car driver’s name is Miguel, but everyone calls him Mike. On some race weekends he gets to drive as few as three laps because, in contrast to F1, accidents on two wheels rarely produce bulky wrecks or dangerous debris. Short, fit and fluent in Spanglish, Mike is evidently a happy camper. ‘I drive everything with everything off,’ is his opening gambit. Responds the minder from BMW: ‘But please guys, please remember we have only this one car.’
To learn the track, Mike leads the way in an X5M driven Carlos Sainz-style. Hot on Mike’s heels, the M4 reels in most corners and the long start-finish straight in fast-forward mode, but at this speed the tyres heat up before I am allowed to give it stick. When the tarmac ahead finally clears, the car leaps forward with a hoarse growl and a whiff of French tyre smoke.
How does the M4 safety car drive?
The extra 75bhp should be a real game-changer, but surprisingly it is not so much the extra urge that makes this M4 special, it’s the much more emotional driving experience. That’s emotional as in loud noise, pungent smells, instant response, deceptive grip, heartbeat feel. When you first hit the Start Engine button you can’t actually hear the siphoning of the water-injection, but you register the louder and deeper voice of the exhaust, which is made of thin-wall titanium and has shed the second silencer for a less compromised flow. Blip the throttle and the rumble will briefly climax in a surround-sound roar before dropping a few octaves again. The other big change concerns the seats, or lack of seats.
The rear bench has gone, and the front seats are thinly upholstered slim-fit Recaro buckets with no height adjustment and fitted with electric blue, six-point Schroth harnesses. Apart from three rocker switches to activate the flashing lights, the cockpit is pure M4, but swathed in carbonfibre, suede and black leather. The lavish equipment includes blindspot and lane-departure warning, air-con, even sat-nav. ‘I have programmed the M buttons to my liking,’ beams Mike. ‘M1 equals Sport mode, hitting M2 deactivates all electronic aids. Enjoy the car!’
Handling on track
At first though, I don’t. Not to the extent I had hoped for, anyway. For a start, I keep veering off the racing line, cursing myself for not practising on the PlayStation. Then something increasingly odd starts happening to the tyres: they lose grip, and quickly degrade. After only two laps, the thing feels as if it’s rolling on raw eggs. There’s frustrating understeer followed by random snap oversteer, merely touching the kerbs requires an instant flick at the wheel, shifting up in the middle of a fast corner is an absolute no-go. Which is not helpful on Losail, where certain sections are too fast for third and too slow for fourth. I catch myself thinking that a 911 or a Cayman would be a much nicer, more composed and even faster drive, but then comes a shock when I pit after only two laps and the crew check the tyre pressures. The result: 66psi all-round instead of a recommended 30psi. Not good at all.
Right now BMW won’t officially confirm that the road version of this M4 will even be badged GTS, since the acronym is also used by AMG and Porsche. They may call it CSL (coupe sport lightweight) – a moniker created in the early ’70s for the legendary Batmobile, which returned in 2003 for a special-edition M3. They’ll save up to 100kg by removing the rear seats, making doors and lids of aluminium, and fitting carbonfibre buckets, hollow-spoke rims and a decontented interior. The rollcage will be an optional extra, but all the drag-cutting addenda featured on the pace car are likely to be carried over. These are part of the M Performance aero kit, featuring front splitters and blade, bespoke sill extensions, more slippery door mirrors, smoother undertray, lift-reducing rear apron and adjustable tail rudder.
How does BMW's planned water injection system work?
The water-injection’s pipes and tank add about 10kg. In an ideal world, BMW would use the condensation from the AC unit to cool down the intake manifold, but for packaging and sustainability reasons this approach may not materialise until the next-generation 4-series in 2018. At any rate, the H2O reservoir will have to be more accessible than in the prototype, where it is tucked away in the boot. By improving the thermodynamic efficiency, WI is claimed to boost power and torque by up to 8% while reducing fuel consumption by a similar measure.
Its effect is particularly noticeable at high revs and during very fast full-throttle autobahn stints when the water mist helps to tune down the combustion temperature which in turn reduces the knock tendency. In response, the black box can increase the boost pressure and advance the spark timing. Since high-load knock would no longer be an issue, the compression ratio may be increased which in turn works wonders for the performance vs economy equation. Under race conditions, the water container needs to be refilled every time you stop for fuel. Normal driving quintuples the range.
Still in pit lane, we are anxiously waiting for the car to return from its second run, this time on properly inflated tyres. Everything looks good now, except for the weather. Within minutes light drizzle becomes heavy rain, but despite the slippery surface the reset M4 feels much better planted and consequently more confidence-inspiring. Even close to the redline at 7600rpm the engine sounds so stressless, as if it would happily spin into five-figure territory. Since the middle section of the torque curve resembles a pool table, it helps the flow on this circuit to keep the transmission in third and fourth most of the time, with only one downchange into second required as you enter the slowest bend. Not surprisingly, the correct tyre pressure transforms the car. The temperature of the Michelins (255/35 in the front, 275/35 in the back) is now building up more slowly and more progressively, the breakaway characteristics are more benign and the amount of grip that carries the car through the two fast kinks has almost doubled.
How fast is the BMW M4 with water injection?
Although BMW is still coy about performance figures, I reckon the production model will hit 62mph in under 4sec (the regular M4 does it in 4.3) thanks to adjusted gearing and some fettling of the M-diff, which does a better job distributing the torque than putting down the power. But even 3.9sec wouldn’t eclipse the heavier 510bhp AMG GTS (3.8sec), the lighter upcoming 470bhp Audi TT RS or the awesome Porsche 911 GT3 (3.5sec). Top speed is normally governed at 156mph, but the optional M Driver’s Pack will hoik that to 181mph.
Pricing? Well, the M3 GTS launched in late 2009 offered a power boost to 450bhp in exchange for more than £90k – double the outlay for the 420bhp version. A similar strategy reportedly applies to the spicier M4, tipped to cost just under £100k. But unlike the GTS, of which only 150 pieces were made, BMW plans 750 units of the M4 GTS/CSL.
Is it worth the extra outlay?
To find out, I wrangle ten more minutes out of the increasingly nervous MotoGP squad. This time, no photography, just driving. Hard, but not as hard as the unlucky Spanish doctor who damaged his X5M medical car the day before by cold deformation. This time, it’s DSC off plus a mental memo not to overheat the front tyres. And, voilà, it works! At last it is back, the enticing mix of sharpness and compliance, agility and smoothness, poise and intuition. Corner by corner, the enchanted brain wanders further down, through the hip into the right foot. Like the bike riders who are already warming up their engines, the person at the wheel of this M4 needs plenty of patience to tackle the slow esses where less is more, and too much will result, you guessed it, in a spin.
But what makes the heart thump are the looong third-gear arcs which issue an open invitation to throttle-steer the M4 all the way through to the next set of chevrons. The adjustable coil-over suspension unique to this model keeps body roll in check and absorbs deceleration dive. With a less firm calibration, this set-up should be fine for normal road driving. The carbon-ceramic brakes are strong and full of stamina, but you need whaam-whaam-whaam downshift support to turn in.
When race control switch on the red lights the session is definitely over, but the M4 GTS has made its point. This car is not merely about grunt and oomph. What gets you hooked are the intensity and intimacy that define the adventure of putting the BMW to the limit. Everything is familiar, yet most things are different. Driving position, overall agility and precision, the sharpness of the handling and the sweetness of the feedback, the delightful steering, the neatly balanced chassis and that unique ready-for-action attitude which must always remain a forte of every M car.