Skip advert

Kleeman SLK55K S8: Special K

Kleemann's supercharged SLK AMG has the performance to scare an SLR McLaren

Denmark is best known for its bacon, but after today I shall always associate it with a totally mad Mercedes-Benz SLK. And the thing that really threw the dynamic qualities of this modified car into sharp focus was a drive in another ultra-quick Mercedes product. Last month, you see, I drove a Mercedes SLR McLaren for the first time. Quite an occasion for a Woking boy. We've got a Martian invasion, The Jam and the McLaren F1 team to be proud of and now to that we can add an exotic supercar. Unfortunately, driving the SLR turned out to be an anti-climax. The SLR is exceedingly quick because even a hefty 1725kg GT stonks along a bit when there's 627bhp in its nose. Trouble is, it's far too big and wide and therefore very difficult to place accurately on anything narrower than a runway. Also, its carbon discs are very effective at stopping the car but lack feel not just when you're applying the stoppers but also when you come back off them. In the wet, traction control should be left on unless you're a Finnish rally hero because the auto 'box will occasionally kick-down when you're not expecting it, causing all sorts of worry. The SLR has pedigree and raw power but, that said, it's disappointing to the brink of pointlessness. Not a quality you'd imagine could be applied to a car costing £313,495. And if you need any further convincing, the Kleemann I'm driving today costs a third of the Woking Merc's price but provides at least double the fun. Kleemann has been around since the mid-1980s, taking ordinary Mercedes and turning them into something rather different. Its latest product is the SLK55K S8, and what an unbelievable piece of kit it is. The most important fact that you need to know is that this car packs 596bhp - only 31bhp shy of the SLR. The second important fact is that the S8 weighs just under 1500kg - a number close to the 1400kg that was Gordon Murray's target weight for the SLR until Mercedes loaded it with telephones and a jacuzzi. Kleemann starts with a standard SLK55 AMG, powered by the same naturally aspirated 5.5-litre V8 that's fitted to the CLK55 and C55 AMGs. Kleemann then fits its own Swedish-designed Lysholm supercharger to the motor. The twin-screw blower is unique in that it's 'in-unit' with both the intake manifold and a patented air-to- water intercooler. To fit the system it's not necessary to remove the car's engine so it's barely more than a day's work to carry out the conversion to either a new or used SLK55. Fitting the supercharger alone lifts power to 550bhp. The S8 (which denotes the Stage 8 tuning package) also has Kleemann's own stainless steel headers, a quartet of racing cats, and a pair of sports camshafts, which together up the power output to 596bhp at 5800rpm. Apparently the standard Mercedes exhaust system is extremely restrictive and creates exhaust back-pressure at medium to high engine speeds. Back pressure is bad news on a supercharged engine because the pressure tries to stall the blower, making it work harder. And that extra effort saps power from the engine. The Kleemann range of Mercedes tuning goodies and engine conversions is imported into Britain by Kleemann Ltd (UK), which is based in a small garage in the East Sussex village of Mayfield. It's a picturesque spot, but not a place you'd expect to find 500bhp+ tuned cars. Nor is it a place where using them in anger would go down well, so as soon as we've collected the car we head south for the cracking Eastbourne to Seaford road that runs along the top of Beachy Head. You can't hear the supercharger working, all you can hear is the most fantastic rumble and bark from the V8. There's not a huge performance advantage in paddling up and down the gears, but a massive emotional one. The motor just explodes in front of you in a wall of sound and objects that were way in front of you are suddenly not. Onlookers don't expect this level of orchestral drama from an SLK. Considering what it can do, the S8 is pretty subtle. Only the fancy wheels really make it stand out from a cooking model. A very hot sun has removed every molecule of moisture from the road surface. This is very good news, especially for the owners of this car. I dread to think what it must be like on a slippery surface. Mercedes-Benz traction control systems are right out of Orwell's 1984 and usually unwilling to permit even a little bit of fun. The S8 laughs in the face of intervention. Mash the throttle to the floor and even with the traction control on there's an explosion from the tail as both rear wheels spin-up, are electronically checked, and then spin again. Behind you is left a morse-code-like pattern of tyre marks on the road. Turn it off completely and you can lay rubber from one side of the county to the other. Or from standstill to your local tyre warehouse. The topping weather has also attracted a large number of motorhomes and retired folk in old Rovers to the area. None are driven briskly but none are more than a few seconds' irritation for the S8 driver. Even in this left-hooker - rhd is available - overtaking is dead easy. Pop it down a gear to get the correct soundtrack and stand on it. Very few cars accelerate with the Kleemann's vigour. Predictable, instantaneous, reassuring overtaking power. No worries about dropping off the cam or losing boost, just a massive shove. The motor has 568lb ft of torque from 2000rpm onwards and Kleemann claims a 0-62mph time of only 3.7sec. It's very believable. This engine in the previous SLK - and several madcap tuning companies did put monster motors in it - would have created something barely more than a hot rod, but the new SLK is four times the sports car its predecessor was. It steers accurately and has far better body control. The ride is pretty stiff, but that's not surprising given the wheel and tyre combination on this car, and the fact it was developed far away from Britain's bumpy roads. Time to get the calculator out. As you might expect, rather large numbers are involved. First, we have to tap in £55,000 for the standard SLK55 AMG. The combined supercharger/ intake manifold/intercooler costs £14,094 (inc VAT) plus £1051 to re-map the car's ECU. If you just have to have the full 596bhp then you'll also need the £4134 tubular headers and the £4562 stainless system. Finally, the camshafts at £4347. That'll get you the full power of the S8. If you want an exact replica of the car we're driving then you're looking at the thick end of six grand for the wheels and tyres and £2643 for the limited-slip differential. It all adds up to an extra £41,000 over the price of the car. I'd stick to just the performance-improving parts and leave the car on standard wheels and body. That alone brings the price into the £70Ks. You could also decide to do without the 46bhp that the exhausts and cams bring with them. After all, an SLK with 550bhp is not going to be a slouch. But I'd want the full experience. You can't apply standard economics to a car like the Kleemann S8 because it's so far down the nutty road. Name me another car with almost 600bhp that costs less. Better still, name one with a power-to-weight ratio circa 400bhp per ton for this sort of money. A couple of years ago I drove the Brabus SL65. Mad as a box of frogs and immensely fast. In truth, though, a bit over the top and not really worth the extra it cost over a standard SL55 AMG. In Germany it was a real blast, the way it would surge from 150 to 185mph in what seemed the blink of an eye. In the UK, however, you'd struggle to have as much fun with it anywhere other than Santa Pod. This is where the Kleemann S8 is different. You're buying a modern version of Shelby's 427 Cobra. A small and manageable car (alright, maybe a 7-litre Cobra isn't that manageable but you know what I mean) that's fairly discreet but packs a massive punch.


 Kleeman SLK55K S8
LocationFront, longitudinal
Cylinder BlockAluminium alloy
Cylinder HeadAluminium alloy dohc per bank, 24 valves, Lysholm supercharger
Max Power596bhp @ 5800rpm
Max Torque568lb ft @ 2000rpm
TransmissionSeven-speed auto, Kleemann limited-slip differential, rear-wheel-drive
Front SuspensionMacPherson struts, coil springs, gas dampers, anti-roll bar
Rear SuspensionMulti-link, coil springs, gas dampers, anti-roll bar
BrakesCross-drilled and vented discs
Wheels8.5 x 19in fr, 9.5 x 19 in rr
Tyres235/35 ZR19 front, 265/30 ZR19 rear, Dunlop SP SportMaxx
Weight Kerb1495kg
Power to Weight405bhp per ton
Max Speed187mph (limited)
Basic Price£90,640 (as tested, see text)
On SaleNow
0 to 60 MPH3.7sec (claimed)
Skip advert
Skip advert

Most Popular

Ford Mustang GT 2024 review – old school in all the right ways
Ford Mustang GT – front

Ford Mustang GT 2024 review – old school in all the right ways

We loved the new Ford Mustang in track-focused Dark Horse form – how does the standard GT fare?
23 May 2024
BMW M135i 2024 review – a match for the Volkswagen Golf R?
BMW M135i review

BMW M135i 2024 review – a match for the Volkswagen Golf R?

BMW’s hot hatch is a good car, but no longer a unique one, and misses the mark for pure fun
22 May 2024
BMW M340i xDrive Touring Fast Fleet test – 6000 miles in the six-cylinder estate
evo Fast Fleet BMW M340i xDrive Touring
Long term tests

BMW M340i xDrive Touring Fast Fleet test – 6000 miles in the six-cylinder estate

The six-cylinder M Performance estate departs the evo Fast Fleet, confirming a renaissance for the everyday BMW
20 May 2024