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      03-09-2010, 05:45 PM   #1
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Drives: F80 M3
Join Date: Mar 2005
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Cool a-workx M3 proves that balance beats power on the track (great article!)

From bimmer-mag:

Simply Well Balanced
With well-executed but modest modifications, the a-worxk M3 wins its class at the 2009 Tuner Grand Prix, proving that a well-balanced car will beat a more powerful one every time.

By Ian Kuah
Photography by Ian Kuah

To make a car quicker from A to B, you don’t need more horsepower. Better handling and braking alone can do the trick, though it helps if the car also becomes more user-friendly and confidence-inspiring at the limit.

Better handling does not always mean stiffer, however, especially on public roads that fall short of Germany’s billiard table smooth tarmac. Here, a good secondary ride is needed to filter out the short, sharp bumps that can upset a powerful car mid-corner, just as it’s trying to deploy its horses for the exit.

And for track day use, a car’s suspension geometry is just as important as its shocks and springs, but geometry adjustments are rarely possible on unmodified road cars. Even the E92 M3, which is as close to a street/track car as BMW makes, doesn’t allow for the kind of front camber adjustment required to make full use of sticky R-compound tires.

Most M3 drivers will likely never notice the absence of such adjustments. But if you want to get the most out of the car on the street or at track days—or if you want to win your class at the Sport Auto magazine Tuner Grand Prix held every year at Hockenheim—you’ll need to figure out a way to work around it. And that’s exactly what German tuner a-workx did before entering its M3 in the Tuner GP’s Saloon Class for normally aspirated, street-legal cars.

Despite being only lightly modified compared to its direct competitors, the a-workx M3 managed to take the Saloon Class win ahead of cars like the C63 AMGs entered by Väth and Lorinser. To do so, a-workx honed the M3’s handling and grip to make full use of its available power, a formula that proved ideal on the relatively short and twisty Club Circuit at Hockenheim.

From Ferrari Challenge to Tuner GP

Based in Munich, a-workx is the brainchild of entrepreneur Franz Wieth, a hard-core enthusiast who in the early 1990s entered a 348 GTB in the German Ferrari Challenge. In 1999, he founded Wieth Racing to prepare road and race cars for customers, and in 2003 that company was taken over by his son, Niko. In 2006, Niko founded a-workx to address road car tuning activities, incorporating Wieth Racing into the new operation as its motorsport division.

Today, a-workx prepares cars for its own racing team (managed by Florian Hebel) and those of its customers, who enter their Radicals, BMWs, MINIs and Porsches in championships like the MINI Challenge, Porsche Carrera Cup, Porsche Alpenpokal and the Porsche Sport Cup, which a-workx won in 2009.

All this experience—as well as plenty of practice preparing street/track cars for customers—was put to good use sharpening the M3 DCT’s claws to make it work on both road and track. If exquisite overall balance is the cornerstone of the M3’s repertoire, only a foolish tuner would upset it. Any power increase has to be matched by a chassis upgrade, and the brakes have to be up to the task of corralling the extra horses, as well.

In Euro spec, the standard M3 puts out 420 hp at 8,300 rpm and 295 lb-ft of torque at 3,900 rpm. Since a-workx is the official German importer for exhaust manufacturer Akrapovic, one of the Slovenian systems naturally took the place of this M3’s stock exhaust. The Akrapovic Evolution exhaust system for the M3 consists of flow-optimized link pipes with a pair of 100-cell metallic catalytic converters, integrated resonators and free-flowing rear silencers.

Made entirely from titanium, this system shaves a useful 50.6 lbs. and lowers backpressure by nearly 50%. Lowering back pressure is particularly useful for gaining power and torque in forced aspiration engines, but it can have a negative effect on naturally aspirated engines. In this case, it worked as intended, achieving the perfect balance of increased power and torque while giving the M3 a more sporting, bass-rich exhaust note.

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On the dyno, the car shows an increase of 24 hp from 2,500 rpm upwards, along with an additional 25.8 lb-ft of torque throughout the rev range. The Akrapovic system also smooths out the dips and troughs in the factory power and torque curves, particularly between 3,500 and 6,500 rpm, and it required no additional ECU programming to achieve the desired effect. (The stock ECU adapts to the exhaust system’s lower backpressure automatically.)

While the a-workx M3’s 444 hp and 321 lb-ft might sound paltry compared with the numbers posted by the tuned C63 AMGs like the 575-hp Väth car mentioned earlier, power isn’t everything. In the case of the a-workx M3, its win over such powerhouses resulted instead from its 50/50 weight distribution, better suspension control and the ability to use almost all of its power more of the time. Another significant contributor to the car’s performance was the super-fast M-Double Clutch Transmission that saves around 1.5 seconds a lap over the manual at Hockenheim.

“The ‘box is absolutely superb on track, shifting like greased lightening,” said multiple Tuner GP winner and FIA GT Championship racer Wolfgang Kaufmann, who drove the car at Hockenheim. “Like a proper race car sequential gearbox, it takes away the distraction of a clutch and gearshift, enabling you to fully concentrate on your lap times.”

The manual may be more involving for the street driver, but there’s no getting away from the fact that not even a pro can approach DCT’s shifting times with a manual. DCT so convincingly chips away at lap times that the next question becomes how to get even more real world performance from your M3 without either compromising the integrity of its fabulous V8 or taking out a second mortgage on your house.

Lower and lighter

a-workx has one answer: KW coil-over suspension that’s adjustable for ride height plus compression and rebound damping. The coilovers were made to a-workx’ specifications, with settings calibrated by Kaufmann. The KW coilovers are paired with a-workx’ own solid suspension top mounts, which are stronger than standard and allow more negative camber to be dialed in for improved grip. Reducing the ride height—the car sits 30mm lower than a stock M3—also requires some recalibration of the geometry, and the mounts allow a-workx to adjust settings for camber and toe. Before sending the M3 onto the track at Hockenheim, the company also corner balanced the car with the driver on board.

All of that allows the a-workx M3 to get the most out of its tires, which for the Tuner GP were dry-weather, racing-compound Michelin Pilot Sport Cups. (Since the M3 comes with Michelin Pilot Sport Cup rubber as standard, the rules allowed a-workx to use a similar tire with a different compound.)

The Michelins measure 235/35ZR-19 front and 265/30ZR-19 rear, and they’re mounted on 8.5 and 10.0 x 19-inch OZ Racing Ultraleggera HLT alloys. Although they’re cast, these OZ wheels are practically as light as forged alloys in the same sizes. Weighing just at 20.9 and 22 lbs. each, front and rear, they save a total of 20.7 lbs. over the standard M3 wheels.

If BMW’s M cars have a weakness, it’s their brakes. Rather than go with an expensive big brake kit, a-workx addresses this with braided hoses and ceramic composite brake pads to better resist heat. These pads are perfect for track days, yet they don’t squeal in normal road use.

Though economical, the setup obviously works, as evidenced by the fact that the car won its class. Watching Kaufmann push the M3 right to the edge during his Tuner GP laps revealed a further impression, which is that the car looked totally lacking in drama even at the limit.

It looked consistent, as well. To win his class in the Tuner GP, Kaufmann had to post not the fastest single lap but the fastest average over five laps. Kaufmann’s 1:12.534 sec average lap and 1:12.201 second-fastest lap were not only enough to beat the more powerful Väth C63 AMG—which recorded a 1:13.056 average and a 1:12.801 best lap—they were also enough to put the a-workx M3 right up there with some of the slower turbocharged Porsches.

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Crisp and quick

After Kaufmann proved the speed of the a-workx M3 on the track, it was down to me to see how well it would perform on public roads, and how suitable it would be as a daily driver. It’s certainly inconspicuous enough, with only its lower ride height, OZ Racing alloys and stripes to differentiate the a-workx car from any other white M3. And apart from its meatier, more bass-laden exhaust note, which leaves a better impression on both occupants and bystanders when it accelerates away, it starts up and drives around town like a standard car, too.

At low speeds, the ride on the KW coil-over suspension is barely firmer than stock. Thanks to a finely honed relationship between the uprated springs and dampers, it retains a good measure of comfort. The damping rates come into their own as the pace picks up, really smoothing out as speeds increase. And when you start to push hard on a twisty road, the suspension really impresses. Once you settle the car into a bend and start to lean on it, you can feel the coilovers’ rock-solid body control at work.

The combination of negative camber and sticky tires means that front-end grip is much improved, and the understeer normally experienced when using a bit too much throttle in a low gear in a tight bend is largely mitigated. This allows you to throttle up a bit earlier, and on track it makes for a higher exit speed from a bend and valuable fractions of a second against the stopwatch.

The different front-end geometry has also improved steering feel. Taking the original E30 M3 as a high point, each generation of M3 after that seems to have added a slight veil to the steering sensitivity. The a-workx suspension settings dial this back a generation, which is a good thing.

The modest negative camber dialed into the front end delivers a quicker turn-in, but there is no feeling of incipient oversteer as rear toe has been adjusted accordingly. If anything, both ends of the car track ’round resolutely until you near the limit, whereupon mild understeer gives way to a four-wheel drift followed by predictable oversteer.

The a-workx M3 has insane levels of mechanical grip, and its relative lack of torque compared to the 6.2-liter AMG also means that it’s harder to unhinge the rear end on good tarmac, especially as BMW’s clever electronic rear differential usually has more answers than a fixed-ratio mechanical diff. When it does let go, the slide is beautifully telegraphed, easy to catch and hold if you so wish. The stock M3 is a great drifter, but with less body roll and weight transfer, the a-workx car is even better.

It’s quick, too: Even though power hasn’t been increased substantially, our GPS-based Performance Box showed the a-workx M3 accelerating from zero to 62 mph in 4.4 seconds instead of 4.8 (as BMW claimed for a stock M3). It also scooted from 50 to 75 mph in 4.0 seconds in fourth gear rather than the 4.9 seconds recorded by BMW at the car’s introduction.

While the increase in power and torque is fairly modest in the overall scheme of things, the slightly crisper throttle response and even greater eagerness to chase down the redline is quite obvious. So, too, is the effect of increased grip and reduced unsprung weight on acceleration.

I have tested plenty of big-power supercharged M3s that are supercar killers in relatively plain clothing. But like supercars themselves, these cars are generally too fast for public roads. Even in Germany, going fast is becoming more difficult just through the sheer weight of traffic. With high speeds no longer a realistic goal, balance becomes ever more important.

Balance is one of the M3’s strong suits, and it’s critical that any modifications take place without disrupting BMW’s finely calibrated relationship between engine, chassis and brakes. The more familiar I became with the a-workx M3 DCT, the more it was apparent that this equilibrium had indeed been maintained. As a four-seat daily driver for sheer driving pleasure on both road and track, this crisp and well-balanced M3 hits the sweet spot.

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