Agent Orange

BMW M3 fire orange color

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With its ground-scraping stance, blackย HREย alloy wheels and retina-searing Fireย 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 BMWโ€™s engine comes to life with a distinctively stock-sounding exhaust note.

Huh? Whereโ€™s the boisterous noise weโ€™ve come to expect from heavily modified M3s like this one?

Oh, itโ€™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.

Itโ€™s a brilliant idea when you think about it. Loud exhausts are fun and exhilaratingโ€ฆto 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.

Agent Orange Engine

With this M3โ€™s iPE Innotech Valvetronic F1 exhaust system, a simple press of a button reduces the engine note to a polite burble, one thatโ€™s quiet enough to convince the local constables that your taste for bright orange cars doesnโ€™t necessarily mean youโ€™re a speed-addicted lunatic.

But letโ€™s be realistic: If youโ€™re driving an M3, you probably are a speed-addicted lunatic, something thatโ€™s most definitely true if youโ€™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 byย BMWย on the Euro-only M3ย GTS, the carโ€™s stock front bumper has been replaced with Arkymโ€™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 Arkymโ€™s carbon fiber diffuser.

Agent Orange Rear End

HREย supplied a set of P43 alloy wheels, which measure 10.5 ร— 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 toย ESSย Tuning for help under the hood. Founded in the Netherlands in 1995,ย ESSย produced a scant 30 supercharger systems for BMWs in its first year. Before long, however, the companyโ€™s products started attracting attention from enthusiasts in the U.K., Germany and even the U.S., thoughย ESSย didnโ€™t officially import its products here until 2005. Once that process began, the response was so positive thatย ESSย set up a North American headquarters in Chandler, Arizona in 2008. According to Roman Zepeda, head of marketing for the companyโ€™s U.S. division,ย ESSย 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,ย ESSย developed a forced induction kit to augment the carโ€™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 cajoledย ESSย into delivering a prototype of the even-more-powerful VT2-650, which wasnโ€™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

Interior of the Agent Orange

Like the more conservative systems, the VT2-650 uses a Vortech V3Si centrifugal supercharger, the same unit found on all of the companyโ€™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 ESSโ€™ 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 itโ€™s a complete kit, the VT2-650 also includes high-temperature hoses and custom-milledย CNCย 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 ESSโ€™ recalibrated software settings, which also remove BMWโ€™s 155-mph top-speed governor. The kit also includes a 100,000-mile drive belt with additionalย OEMย rollers and a sturdier crankshaft pulley designed to work specifically with the VT2-650, plus anย ESSย 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 settingsโ€”On, Off or Autoโ€”to be selected by remote control from the carโ€™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 engineโ€™s throttle position sensorโ€”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.

Side of the Agent Orange

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

Whenย ESSย 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 700โ€”a big increase over the stock engineโ€™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 โ€œMโ€ button unpressed. Switch the exhaust valves to Off and press that little โ€œMโ€ button on the dash, however, and the equation is altered drastically, resulting in the most intense modified M3 Iโ€™ve ever experienced.

A Demented Level of Acceleration

Put simply, thisย BMWย 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 DCTโ€™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 protestโ€”or is that joy? Even though the Toyo tires and KW Clubsport coilovers deliver sky-high grip, itโ€™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. Itโ€™s as loud as anย ALMSย 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. Thereโ€™s no way to explore this carโ€™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 thatย ESS delivers on its promise of huge power with no loss of driveability. Itโ€™s a good match for Arkymโ€™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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Rick Wilkinson

Hi, Iโ€™m Rick. Iโ€™ve been fascinated by cars since I could barely reach the pedals, and I turned that passion into a career. With over a decade working hands-on in the automotive industry, Iโ€™ve spent years learning what makes vehicles tick. Now, Iโ€™m here to share my knowledge and help my readers. Check out my articles!