Mercedes-Benz SLR 722
Limited Edition SLR loses weight and gains power
It was a personal best. A nice round 200kph over the speed limit. Dead straight, perfectly surfaced, deserted dual carriageway, not a soul in sight. The limit was 80kph, set that low because of danger from stray camels. But there were no camels within the featureless vista scanned by our hyperactive eyes, so no danger.
OK, I wasn’t driving at the time. But that doesn’t much lessen the illicit thrill of almost 175mph on a public road that isn’t a German autobahn, especially given the continuing savagery of the acceleration right up to the point of backing off. The Mercedes-Benz SLR McLaren may not be the apogee of the supercar art that its price suggests it should be (how can it be when a Ferrari 599 is better in nearly every way and costs around half as much?), but there are some things it does with panache.
Besides, the SLR we’re driving is the car that could salvage the model’s reputation. Called (deep breath) the Mercedes-Benz SLR McLaren 722 Edition, it has been built in response to some existing SLR owners’ desires for ‘more sportiness’. As if 208mph and a 3.8sec 0-62 time weren’t sporty enough already…
There will be just 150 722s, and instead of costing the usual £317,610 it will relieve you of £334,300. You may already know what the 722 bit means. Stirling Moss and Denis Jenkinson won the 1955 Mille Miglia road race in an SLR racer bearing the number 722, which denoted the car’s 7.22am start time. Moss drove the whole way himself at an average speed which was never beaten. Today’s SLR has no competition history of its own, but it basks in massive reflected glory.
Long term tests
The extra £17K that makes the 722 difference doesn’t seem, objectively, to buy you much. Most important to the way the 722 drives are the new front splitter, suspension lowered by 10mm and new Koni dampers set 15 per cent stiffer in bump.
The splitter increases front downforce by 128 per cent, and the flip-up rear wing (deployed at very high speed or under firm braking) rises up a further five degrees to help balance the new forces. The dampers have aluminium casings, which are lighter than the steel shells of the previous Bilsteins, and the new wheels are also lighter to the further benefit of unsprung weight. The brake discs are still carbon-ceramic but the front ones are now bigger.
There’s also red detailing for the engine intake tract, brake callipers, upholstery and dials, plus three ‘722’ badges (two on the front wings, one by the gear selector) and – vitally – a modified engine-management map. This raises the supercharged, 5.5-litre AMG V8’s power from 617 to 641bhp and its torque from 575 to 605lb ft. And that puts 1mph on the top speed, making 209mph, and shaves 0.2sec from the 0-62mph time, now down to 3.6sec.
There’s a sense of menace about an SLR when you press the starter button concealed under the gear selector’s flip-up lid. Those four side-exit exhausts harrumph and splutter, their aural explosiveness the greater for their proximity to your ears. The extra power and the 722’s 44kg weight loss help create an even bigger explosion on that first exploratory prod of the accelerator pedal, too, helped by a torque converter in the five-speed auto ’box that’s keen to lock up as quickly as it can.
Unlike most other Mercedes-Benzes, the SLR has a proper manual mode for its transmission, which neither downshifts on throttle-flooring nor upshifts at the rev limit. You can select three different shift speeds for the sequential paddle-shifters, the fastest of which does a passable imitation of a Ferrari F1-shift, even if it isn’t quite as quick.
It’s not great at synchronising engine speed with road speed on a downshift, but unlike most autos it lets you apply your own meaningful throttle-blip to keep things smooth. There’s a lovely burst of supercharger whine as you do this. And, unlike a Ferrari-type robotised manual, the transmission is guaranteed to be smooth in automatic mode, even in the quicker-shifting sport setting. This is a good transmission, well matched to the engine’s bombastic torque.
So far, so pretty damn fine. But, Houston, the rocketship has a problem. I’m driving on what looks like a smooth, flat section of Dubai desert road, where what few bends there are can be happily taken at two or three times the posted advisory limits, but the 722 seems to be inventing bumps of its own. There’s a constant vertical choppiness at the back, as if springs and dampers are badly mismatched (the springs themselves are standard and merely sit on lower platforms).
And now, at last, a sinuous mountain road. Healthy speed, not excessive, turn-in and – good grief! I have never known a road-going car with a fiercer turn-in than this one. Up to now I’ve felt the steering to be quick and very positive, with more weight and feedback than the standard SLR, but suddenly there’s a whole new dimension to its character.
The turn-in loads up the outside rear wheel quite violently, which tightens the line as if leaning on a big spring. So I pay off a little lock, the loading goes, and now the SLR isn’t turning tightly enough. So I steer a little more again, and the process is repeated. There’s a huge amount of grip, albeit moveable grip, but the 722 is very hard to place accurately. Corners are taken in a series of bites.
Why does it do this? A 599 turns and stays stuck to its line, subtly adjustable as needed. A 722 feels hyperactive; not nervous, exactly, because it is essentially benign despite initial threats of huge oversteer, but very physical as you battle away with endless steering corrections. Is it the damper settings? Are they too stiff? The engineers don’t think so. For them, the 722 is just ‘a bit more sporty’, as intended.
This is a curious car. The brakes still have a long, springy travel, although they are easier to modulate than they were. The silver-painted plastic vents and details in the cabin are outrageous in a car of this cost; why aren’t they made from machined aluminium? And the seats give you a numb bum, despite the car’s GT credentials.
It’s blazingly rapid and it can be a lot of fun, but the 722 makes no sense in a world that contains the Ferrari 599 GTB Fiorano. Not that this will matter to the 150 722 buyers. Anyway, there’s an SLR roadster on the way, so let’s hope the Big Mac finally gets it together then.
|Engine||V8, 5439cc, 32v, supercharger|
|Max power||641bhp @ 6500rpm|
|Max torque||605lb ft @ 4000rpm|
|Top speed||209mph (claimed)|