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The Dinan-tuned M2 S2 turns BMW’s modern classic up to eleven

The BMW M2 is a spiffy coupe right out of the gate, but what would it take to make it better? If you ask Nathan Fette of Dinan, a tuning company based in Morgan Hill, CA, it starts with one overriding objective: “to develop the fastest, best handling and most reliable, street legal cars available anywhere.”

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It’s going to take a little more than a hearty spirit, mind you. You’ll need a litany of upgrades, more power, and some careful engineering to better one of the best from the Bavarian automaker. With that in mind, We sat down with the folks from Dinan to get a better understanding of the company’s strategy when tuning a vehicle like the BMW M2, and then headed out to some of our favorite Californian backroads for some seat time in their latest offering.

Improving performance without typical aftermarket caveats

The tuning company’s tweaks to the diminutive coupe are extensive enough to warrant a new name, the Dinan M2 S2, and the modifications touch on the drive train, suspension, brakes, rolling stock, and aesthetics to elevate the car into a performance realm beyond what the factory had in mind. “Our goal is to make the driving experience even more exciting without sacrificing the refined handling, reliability or warranty coverage that owners of such vehicles can come to expect,” Fette explains.

While some of that might come across as a bit of hyperbole, there’s an important takeaway there too, and that’s the emphasis on reliability and Dinan’s warranty coverage. Ultimately, there are a lot of different routes that owners can take to bolster their ride’s performance, but whether or not it will impact the car’s temperament is often a mystery that’s only revealed some time later. Considering that, Dinan’s commitment to their products with coverage that matches BMW’s own factory warranty on vehicles like the M2 speaks volumes about the company’s confidence in their engineering.

It also means that Dinan performance enhancements, and the cars they have been installed in, are covered for up to four years or 50,000 miles, which includes any potential consequential damage.

The Dinan M2 S2

Founded in 1979, Dinan has become one of the preeminent tuning outfits over the years for BMWs. Its known for their OEM-like execution and commitment to a level of quality and refinement that jives with the tastes of this particular faction of owners. The company has also served as a technical partner to BMW Motorsport in the Rolex Grand-Am Daytona Prototype series, and has contributed to the team’s back-to-back-to-back championship successes as well as and two overall wins at the 24 Hours of Daytona.

As you might expect, lessons learned out on the racetrack often find their way into engineering solutions for Dinan’s road-going offerings. The latest vehicle to go under the knife is BMW’s newest M car, the M2. Lauded as something of a return to form for BMW’s performance division, the M2 offers a sense of balance, relative simplicity, and driving engagement that’s been pushed toward the background of other BMW M models in recent years.

Looking at the extensive list of modifications the tuner has done to create the M2 S2, that aforementioned coverage certainly looks reassuring. With that said, we’re also left to wonder if they’ve inadvertently altered those balanced fundamentals that make the M2 such a joy to drive.

As you might expect, lessons learned out on the racetrack often find their way into engineering solutions for Dinan’s road-going offerings

“In stock trim the M2 is a well-rounded vehicle. It harkens back to the E36/E46 M3 days where the car was about balance in power and handling with a footprint that let nimbleness be a major contributing factor,” Dinan’s Dan McNiff tells Digital Trends. “Whereas most new cars have simply gotten bigger, softer, and try to compensate with more output, the M2 bucks that trend. We wanted to really emphasize what sets the M2 apart as a driver’s car while maintaining that overall sense of a well-rounded vehicle that is not simply all about a lot of power or creature comforts.”

But don’t think for a second that Dinan has ignored the motor in this myriad of enhancements. Output now stands at 446 horsepower and 458 pound-feet of torque, gains of 81 hp and 115 lb-ft over the stock M2. The additional grunt comes from a host of changes that start with an engine management tune that Dinan touts as the only emissions legal aftermarket ECU on the market. “The backbone of any tuned setup is the engine tune itself, which allows optimization of boost, air, fuel, and lambda targets among other variables,” Dinan’s James Leong tells Digital Trends. “These specific parameters allow the car to extract as much power as possible out of the engine.”

That software tweak is required in order for the ECU to process the additional fuel and air coming in, the latter of which are delivered by way of a Dinan cold air intake system and a turbo upgrade to the M2’s 3.0-liter six cylinder motor. “The compressor wheel inside the turbocharger is increased in size allowing around 30 percent greater flow, thus enabling additional boost pressures at higher engine speeds while retaining efficiency,” Leong explains. “These are rebuilt factory turbos that are machined to Dinan specifications, along with an upgraded thrust system to ensure reliable and prolonged life.” On the other end of the combustion formula, Dinan’s stainless steel high-flow exhaust system and resonator delete kit let the engine breathe easier while enhancing the car’s sonic character.

Out on the road, what’s striking about the engine modifications is how stock-like the car’s behavior remains. Like the factory M2, power delivery remains surprisingly linear and the throttle inputs are easy to modulate with similarly predictable granularity – it’s just that the pace has changed for the better. Dinan doesn’t offer instrumented testing performance specs, but our tuned-and-toned backside data logger indicates that the sprint to 60 mph from a standstill is more than a couple of ticks quicker than BMW’s quoted stock time of 4.2 seconds when equipped with the DCT gearbox. That should put it on par with a factory M4, if not a bit quicker.

Dinan’s commitment to their products with coverage that matches BMW’s own factory warranty speaks volumes about the company’s confidence.

The M2’s suspension system was another key focal point for modification. Dinan’s adjustable coilover system is the center of the package, a setup that allows for ride height adjustments that provide up to a one inch lower stance up front and up to and inch and a half at the rear, while spring rates are up about 18 percent in front and 5 percent in the back. The coilover setup is supported by a host of other Dinan suspension pieces here that include upgraded sway bars with adjustable end links, adjustable camber plates, a rear suspension link kit and a tension strut ball joint kit.

“We wanted to pair the drivetrain modifications with a suspension system that allows all that power to be delivered to the ground and used effectively,” says Fette. “The suspension setup is designed to dramatically improve grip in the corners for reduced understeer, sharp turn-in, a substantial reduction in body roll as well as reducing dive under breaking and squat under acceleration.”

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Out on the pockmarked streets of Los Angeles, the new setup does have a stiffer ride over small imperfections in the road, likely due to this test car’s adjustable suspension being lowered as far as it’ll go to bring the center of gravity down and enhance the visual drama. But getting the car out to some twisting stretches of tarmac in the San Gabriel Mountains puts the Dinan M2 S2 in its element, where Dinan’s modifications have yielded an M2 that is eminently planted, composed, and clearly poised to hold its own at your next autocross or track day.

Going a la carte

The old hot rodder’s mantra of “fast, cheap, and reliable – you can only pick two,” is not betrayed by the Dinan M2 S2. All in, our tester – which was outfitted with the optional forged wheel and tire package, along with a Brembo big brake kit –  tallies up a grand total of $28,358 on top of the price of the donor car, and that’s before installation (though it’s worth noting that about $16,000 of that is comprised of the aforementioned wheel/tire/brake package).

If that’s a little rich for your blood, fear not, as Dinan also offers the components that comprise the M2 S2 package as individual parts, allowing owners to do their upgrades incrementally, or focus on specific aspects of their car’s performance if they choose.

Still though, Dinan prefers to think of the M2 S2 as a wholly realized concept. “We employed the same philosophy [as BMW did with the factory M2] throughout every additional upgrade, and ultimately we ended up with what we view as an augmented M2 that doesn’t sacrifice any of its original character or charm,” says Fette. “It just makes it better.”