Agent Orange

Fire Orange paint and bold HRE wheels make this M3 a bravura showcase for Arkym's sexy bodywork. A 604-hp supercharger from ESS makes it an ultra-intense driving experience, as well.

Agent Orange 1
October 17, 2011

With its ground-scraping stance, black HRE alloy wheels and retina-searing Fire Orange paint, this project M3 would be expected to have an audible bark to match its visual bite. Push the Start button, however, and the BMW’s engine comes to life with a distinctively stock-sounding exhaust note.

Huh? Where’s the boisterous noise we’ve come to expect from heavily modified M3s like this one?

Oh, it’s there. All you have to do is press this little button on the remote and blam! Hidden valves open in all four exhaust pipes, allowing the uncorked roar of the S65 V8 to be heard in all its glory.

It’s a brilliant idea when you think about it. Loud exhausts are fun and exhilarating…to a point. The point at which they become decidedly un-fun may be when you drive past a police officer who eyes you suspiciously, or when you want to park in front of a restaurant without shattering the windows along the sidewalk.

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With this M3’s iPE Innotech Valvetronic F1 exhaust system, a simple press of a button reduces the engine note to a polite burble, one that’s quiet enough to convince the local constables that your taste for bright orange cars doesn’t necessarily mean you’re a speed-addicted lunatic.

But let’s be realistic: If you’re driving an M3, you probably are a speed-addicted lunatic, something that’s most definitely true if you’re driving this particular M3. Masterminded by Arkym, a relatively new company that specializes in aerodynamic body parts for BMWs, the car has been built to showcase those parts as well as the tuning philosophy behind them.

Fire Orange firebreather

Painted in Fire Orange, the same color used by BMW on the Euro-only M3 GTS, the car’s stock front bumper has been replaced with Arkym’s AeroRace carbon fiber bumper, which features an integrated carbon splitter as well as aggressive side intakes that arc upwards from the outside before diving back towards the center opening. At the rear, its stock trunk lid was binned in favor of an AeroRace carbon fiber equivalent and its stock rear bumper complemented by Arkym’s carbon fiber diffuser.

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HRE supplied a set of P43 alloy wheels, which measure 10.5 × 19 inches at all four corners and are wrapped with Toyo Proxes 1 tires that measure 255/35ZR-19 at the front and 295/30ZR-19 at the rear. A Brembo big brake kit uses 380mm rotors at all four corners in conjunction with six-piston calipers, while a set of KW Clubsport coilovers allow ride height and damping rates to be dialed in precisely for a variety of conditions.

While those mods might be enough for some companies, Arkym wanted to make sure its M3 was as fast as it looked, so the bodywork manufacturer turned to ESS Tuning for help under the hood. Founded in the Netherlands in 1995, ESS produced a scant 30 supercharger systems for BMWs in its first year. Before long, however, the company’s products started attracting attention from enthusiasts in the U.K., Germany and even the U.S., though ESS didn’t officially import its products here until 2005. Once that process began, the response was so positive that ESS set up a North American headquarters in Chandler, Arizona in 2008. According to Roman Zepeda, head of marketing for the company’s U.S. division, ESS currently offers a comprehensive line of supercharger systems and other power-enhancing components for BMWs and other makes.

When the E90/92 M3 was launched in Europe in 2007, ESS developed a forced induction kit to augment the car’s high-revving, 414-hp V8, first with the 575-crankshaft hp VT2-575 and then with the 600-hp VT2-600 kit. While the crew at Arkym could have installed one of these systems, they went one better and cajoled ESS into delivering a prototype of the even-more-powerful VT2-650, which wasn’t yet available to the public and was the only one of its kind in North America at the time of our test.

A removable supercharger suits a split personality M3

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Like the more conservative systems, the VT2-650 uses a Vortech V3Si centrifugal supercharger, the same unit found on all of the company’s late-model supercharger systems. Inhalation takes place through a high-flow K&N filter attached to a cast plastic high-temperature supercharger intake, which delivers air to ESS’ cast aluminum intake manifold with integrated velocity stacks; on the Arkym M3, this part is wrapped in carbon fiber weave for an improved appearance.

Since it’s a complete kit, the VT2-650 also includes high-temperature hoses and custom-milled CNC brackets that allow the supercharger to be installed and removed without permanent modifications. A high-capacity liquid intercooler ensures adequate cooling while a compact Vortech Maxflow Racing blow-off valve relieves excess pressure. Eight higher-capacity Bosch fuel injectors fulfill the need for additional fuel according to ESS’ recalibrated software settings, which also remove BMW’s 155-mph top-speed governor. The kit also includes a 100,000-mile drive belt with additional OEM rollers and a sturdier crankshaft pulley designed to work specifically with the VT2-650, plus an ESS oil breather assembly.

Spent gases exit through the aforementioned iPE Innotech Valvetronic F1 switchable exhaust. Constructed of stainless steel, the system allows one of three settings—On, Off or Auto—to be selected by remote control from the car’s interior.

In the On setting, valves close off two of the four pipes, resulting in a quieter exhaust note suitable for normal driving. In Auto, the exhaust is controlled by the engine’s throttle position sensor—if the driver opens the throttle fully, the valves in the exhaust automatically open and the sound of the exhaust goes from muffled street car to full-bore race car. In the Off setting, the exhaust valves open up completely and stay open, making the Arkym M3 sound like a race car from idle to redline.

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(Note: This exhaust system is for “off-road use” only—i.e. for track use only—in part because it lacks catalytic convertors. Though we tested it on the street, we do not endorse the use of “off-road only” parts on BMWs being driven on the street, especially when they remove the catalytic converters that help ensure clean air for everyone.)

When ESS dyno-tested the finished car, the VT-650 exceeded all expectations, producing 604 horsepower at the wheels. Take into account a 15% driveline loss and crank horsepower is close to 700—a big increase over the stock engine’s 417-hp EU/404-hp U.S. output.

As effective as it is, the supercharger itself is scarcely audible, leaving little to give the game away so long as the driver goes easy on the throttle while leaving the exhaust in the Off position and the “M” button unpressed. Switch the exhaust valves to Off and press that little “M” button on the dash, however, and the equation is altered drastically, resulting in the most intense modified M3 I’ve ever experienced.

A demented level of acceleration

Put simply, this BMW delivers a demented level of acceleration. As I pull onto one of the bridges that arc into and out of downtown Los Angeles, a full dose of throttle has the M3 lunging down the road, pinning me back in the seat. Pulling DCT’s left paddle for a lightning-fast upshift allows the acceleration to continue unabated as the tires squirm for traction and the rear of the car wiggles in protest—or is that joy? Even though the Toyo tires and KW Clubsport coilovers deliver sky-high grip, it’s still possible to detach the tires from terra firma with an aggressive dose of throttle.

As engine speeds approach redline, the quick-revving S65 V8 engine uncorks an incredibly hard-edged and raspy howl. It’s as loud as an ALMS racer, the sound echoing off nearby buildings as if they were the concrete barriers at the Long Beach GP.

Honestly, the combination of relentless, internal organ-rearranging acceleration and staccato engine note is so intense that words can hardly describe it. Somewhat ironically, this M3 remains an easy car to drive at any speed thanks to its confidence-inspiring handling and quick steering response. That said, this is definitely one of those road tests that really should have taken place on a race track. There’s no way to explore this car’s true capabilities on a public road, especially one crowded with errant drivers in minivans and local police with prying eyes and blank ticket books.

As inadequate as it is, our spell behind the wheel offered sufficient proof that ESS delivers on its promise of huge power with no loss of driveability. It’s a good match for Arkym’s modifications to the body and chassis, ensuring that this M3 goes as fast as it looks without sacrificing the essential balance that makes these cars so fun to drive in the first place.

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