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One-Two Punch
Brabus SLK

Brabus Stuffs A V8 Into An SLK, Hammering Both The Laws of Physics And The Bank Account

Say "small and light roadster with a big V8 motor" and most people will have blurted out the magic words "AC Cobra" before you finish the sentence. But now there is a new contender for the title of lightweight, heavy-punching champion.
About as far from the coke-bottled, wide-arched, muscle bound image of the legendary Cobra as you can get, the sleek Mercedes-Benz SLK is nobody's idea of a muscle car. But cruising the autobahns right now is a discreetly modified black SLK that will leave the line shrouded in a cloud of buring rubber and bounce a menacing V8 rumble off the surrounding countryside.
With a 0-60 coming up in 4.5 seconds, 100 mph in 10.7 seconds and a 178 mph top speed, it will keep station with a hard-charging Ferrari F355 or a Porsche 911 Turbo. But as the SLK's 450 hp reaches the ground through an automatic transmission, its driver will be able to glance sideways and wave while his adversary frantically shifts gears every few seconds. This is ego annihilation made easily.

Pre-emptive Strike

Brabus SLK About two years ago, AMG tried to put their 3.6-liter straight six into the Mercedes-Benz SLK roadster. They ended up with a bump on the front of the hood because they could not get the engine far enough back in the chassis. MercedesBenz was not keen on having a carbuncle on the nose of Michael Mauer's beautiful design and said "Nein!"

In the meantime, Vath Motorentechnik near Frankfurt were a bit more clever and fitted their 265 hp 3.5-liter straight six by making adapter plates to move the engine back in the chassis a couple of inches. This, of course, has the added benefit of improving weight distribution, and the result is the car that Mercedes-Benz should have made in the first place.
For the 1999 model year, MercedesBenz will present the SLK V6 with the silky smooth 3.2-liter V6 motor, and there will of course be a more powerful AMG version as well. At that point, the tuning war for SLK V6s will no doubt be on.
Too late! Brabus have already sidestepped the whole issue and gone straight to the top with their SLK V8. Fourhundred-fifty horsepower from a 6.5-liter V8 is an argument of such strong persuasion that no V6 will ever get a look in.
"It was a logical step for us," explained engineering chief Ulrich
Gauffres, the man behind every technical aspect of Brabus' conversions. "We measured up the engine bay, and as we suspected, the V8 would slot in without too much trouble."
Brabus SLK The new three-valves-per-cylinder SOHC V8 as used in the E430 and E55 can be used in the SLK V8, but this new modular engine has less meat in its block which limits its ultimate capacity to around 6.0 liters on grounds of longevity. So far, Brabus has managed to extract around 420 hp from it.
The prototype SLK V8 uses the older fourvalves-per-cylinder DOHC M 119 motor but substitutes the pre-1996 closeddeck block which has more metal available for increasing the bore. The new square bore and stroke of 101 x 100 mm for 6409cc is achieved with a new longthrow crank machined from a steel billet married to new lightweight alloy pistons and lightened and balanced standard rods which help towards the 11.0: 1 compression ratio. Then Brabus engineers threw a polished intake manifold, gas-flowed heads with larger valves, high-lift cams, free-flow air cleaner and sports metal catalysts into the equation, and were pleased to see 450 hp at 5900 rpm on the dyno. Even more pleasing was the mega-torque figure of 488.6 lbs-ft at 3800 rpm. According to Brabus' engineering chief Ulrich Gauffres, the stock injectors are up to the job once the modified ECU tells them to stay open longer. A totally new ignition curve is also burned into the chip and then the engine requires feeding with super unleaded fuel.
Jaguar freely admits that they buy the Mercedes-Benz five-speed electronically controlled automatic transmission for their new supercharged XJR V8. No wonder really, as Brabus say it will take 517 lbs-ft of torque. So while it may need strengthening to take the grunt of their 7.3-liter V12 motor, it is not out of its depth in the SLK V8.
All the components aft of the gearbox had to be specially made for the car. The propeller shaft is a bespoke item, as is the rear differential base plate. The steel half plates on each side of the differential are welded together to form a cage, and all the points where the axle is linked to the suspension and chassis are considerably strengthened. The rear differential comes from the 206 mph Brabus E V12, which means that it is basically Mercedes-Benz but uprated with special internals and a beefed-up rear axle plate.
Brabus SLK At the front, a special cross-member was made up to carry the V8, and its attachment points to the bodyshell were strengthened. The idea of dropping a huge V8 motor into the SLK may give rise to visions of a packed engine bay and noseheavy handling. In fact, there is plenty of room in the SLK's long nose for this compact alloy V8 whose actual weight is not far off from the four-cylinder engine it displaces. "The four-cylinder engine has an alloy head but an iron block," Uli Gauffres explained. "The alloy V8 is not lighter, but it is not much heavier either." The major increase in weight up front actually comes from the larger radiator needed to throw off the greater heat of the big engine and the engine and gearbox oil coolers. Fully fueled with no occupants, the weight distribution is 53/47 percent with 1764 pounds and 1587 pounds over the front and rear axles respectively.
True enthusiasts agree that the handling of a stock SLK is rather suspect. This roadster rides well at low speeds, but when you go faster, it can pitch around on bumpy roads even in a straight line. It also feels rather nervous through undulating bends, especially in the wet and on loose surfaces where its short wheelbase does it no favors. This is one Mercedes that really needs its ASR.
With that as a starting point, the power and torque of the Brabus car seem like a recipe for a very big accident. But don't forget that Brabus are the premier Mercedes tuner. Don't forget that they are recognized as a manufacturer by the Kraftfahrtbundesamt (German Transit Authority). And don't forget that their cars are so well-sorted that some of the Board members of Mercedes-Benz prefer to drive Brabus cars in preference to AMG, their erstwhile in-house tuner.
This means that any Brabus-tuned car will have suspension and brakes well up to its enhanced performance. In the case of the SLK V8, this meant that while I was glad to see the back of the SLK 230 Kompressor I ran for nine months last year and its cement mixer motor, the balance and poise of the Brabus SLK V8 and its wonderful V8 soundtrack soon became addictive.

Grabbing A Handful

One of my greatest drives ever started off in town as we drifted from stoplight to stoplight through Brabus' hometown of Bottrop. With just a whiff of throttle and a deep V8 woofle, the car zips up to the 30 mph urban limit, cruising through the afternoon traffic. Despite uprated springs and shocks, a bigger front roll bar and the addition of a rear antiroll bar, the ride quality over manhole covers and potholes is amazingly supple. More so considering the 225/40ZR18 and 255/35ZR18 tires on 8.5J and 9.5J x 18 inch Brabus Monoblock IV three-piece alloy wheels that fill out the wheelarches and together with the subtle body styling kit, help to give the car its meaner look.

It is that new suspension setup that raises my eyebrows further once we join the autobahn traffic and I am able to nail the throttle for the first time. With a big roar, the V8 coaxes the transmission into kickdown and we rocket away from the fast-flowing traffic at flank speed. Now the speedometer needle is soaring 'round its arc almost as fast as the tach needle next door, and as the clever net windbreaker device does not fit over the chromed Brabus rollover hoops, the wind noise and buffeting begin to match the deep growl from the big twin exhaust pipes.
The BMW that was gaining fast as we moved from the middle to the fast lane is now a receding speck in the mirror and in scant seconds, we have gone from 60 to 140 mph. All this with the top down and the sun shining. Boy, life is good!
Handling problems are often found by feeling what a powerful car is doing wrong under full steam, even in a straight line. Mercedes-Benz obviously recognized that the short-wheelbase SLK at stock ride height is inherently nervous, and tried to redress the balance by fitting wider rubber at the rear. But it is not enough.
The SLK V8 on the other hand has all the right moves. Even at 140 mph over bumps on the autobahn, the car stays solidly bolted to the tarmac. One undulation I know on this piece of road unsettles the rear of the standard car at two-thirds that speed. The Brabus car on the other hand hardly acknowledges the existence of this imperfection in its path.
Twenty minutes later, we are a fair way from base, and it is time to go home. Turned around, and cruising at a more moderate gait-a mere 100 mph-I have time to reflect on the finer points of the SLK V8 experience. By the way, not included in a pricetag already four times that of a normal SLK is a cosseting bespoke soft leather interior topped off with special wood or carbon trim and a lovely alloy gearshift and handbrake lever. This cabin is a nice place to be.
With its fantastic punch and wonderful burbling, growling soundtrack, the Brabus SLK V8 is more than halfway to acquiring the copyright on fun. It grips and handles in a confidence-inspiring way, too. The downside is that for all its sheer performance, it will never feel as tactile or rewarding in the bends as a 911 or a Ferrari. But does that really matter? Come rain or shine, the SLK V8 also carries over the two strong suits of the standard car-its great looks and that wonderfully clever folding hardtop. The combination is almost priceless.

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