By adding a pair of turbochargers to its legendary inline-six, BMW turned the ever-popular 3-Series into a tuner’s dream. With 300hp and 300 lb-ft in factory spec, the 335i was the perfect starting point for a balls-out performance project – something numerous aftermarket tuners have already proven.
While the tuning potential for the 335i car seemed limitless, not every owner was comfortable invalidating a perfectly good factory warranty in the name of power. Luckily, those customers have a new option in the form of the 335is.

Just announced, the 2011 335is will be available in coupe and convertible form starting this spring. A model exclusive to the North American market – where almost 35% of 3-Series sales are the 335i – the new variant was developed with performance enthusiasts in mind. Upgrades include more power, an optional DCT gearbox, a distinctive body and wheel package plus unique interior trim, slotting it perfectly between a regular 335i and the M3.

Power for the 335is comes from a factory-tweaked version of BMW’s 3.0-liter twin-turbo six-pot N54 engine found in everything from the 135i to the X6. Horsepower is bumped to 320, while torque jumps to 332 lb-ft.

An overboost feature permits up to seven seconds of additional manifold pressure under certain conditions, allowing a temporary spike in torque up to 370 lb-ft.

With extra power comes responsibility (and heat), so BMW fitted a larger cooling system and external oil cooler in the front bumper. And because coupes more likely to see track duty, it sacrifices foglights to maximize airflow through the reshaped ducting in the front bumper. Convertibles, on the other hand, keep the additional lighting.

For further proof that BMW takes a simple power upgrade seriously, look no further than the engine mounts, which have also been upgraded to deal with the added load.

A six-speed manual transmission is standard issue, with no option for a conventional automatic. Instead, BMW offers a seven-speed dual-clutch gearbox (DCT in Bimmer-speak) similar to the one on the M3, complete with launch-control to make you look like a hero at stoplights.

While purists may prefer the six-speed (which is fitted with a factory short-shift kit), there are performance gains to be had with the quick-shifting DCT. The manual 335is coupe gets to 60mph in 5.1 seconds, while the sequential ’box does it in five-flat (convertibles take 5.2 seconds regardless of tranny). Manually shifting the DCT can be done either by bumping the shift knob forward or back, or by pulling on the shift paddles, which now feature dedicated upshift (right) and downshift (left) levers.

Besides shifting faster, the DCT also rev-matches on downshifts, once again making the driver sound like a racing veteran. Upshifts are just as entertaining, especially under full throttle when the exhaust emits a racecar-like burble-fart as the engine speed changes instantly moving up through the gears.

The tuned exhaust system deserves partial credit, delivering a guttural rumble at idle that turns into a melodious rasp as the revs build. This motor music is best experienced from outside the car, and will certainly garner the respect of fellow enthusiasts.

The 335is wears special bodywork in addition to the styling update just introduced for all 2011 3-Series coupes and convertibles. The front bumper has not only been reshaped for greater airflow, but also wears black kidney grilles. Shadowline window trim is part of the package, and the exterior mirrors are painted black for a more aggressive look.

The standard 18” wheels are finished in dark silver BMW calls Ferric grey. They are fitted with staggered-fit 225/40 and 235/35 summer performance tires.

The rear fascia still houses exhaust tips on each side, but also gets an integrated rear diffuser – painted body color with a black accent – that acts as a high-speed aerodynamic aid to reduce rear end lift.

The interior continues the theme, with an anthracite headliner setting the stage for a sportier cockpit. BMW’s textured aluminum “glacier” trim is finished in a dark silver that not only looks more appropriate than wood, but also matched the dark grey dials, which bear the 335is logo. The thick M-Sport steering wheel offers excellent feel and adds to the sincerity of the 335is as a driver’s car. Sport seats, naturally, are standard.

The chassis has the M-Sport suspension on both coupe and convertible, lowering the chassis 10mm. Brakes are four-piston calipers squeezing 13.7” vented discs front with single-piston grippers acting on 13.2” rear rotors.

On the Estoril race circuit in Portugal, the 335is proved itself the ideal enthusiast’s companion. The additional horsepower is modest, but the extra torque makes its presence known; exiting virtually any corner required considered application of the throttle to keep the traction control indicator (or the “happy light” as one colleague called it) from blinking incessantly.

Killing the traction control allowed faster laps, but required a greater degree of smoothness. Defeating the stability control altogether (which BMW forbade us with the eight hand-built prototypes we sampled) would have certainly resulted in massive powerslides and copious tire smoke.

For this brief introduction, the entertainment value of the raucous mechanical sounds of the turbocharged-six and its sport exhaust meant nobody was disappointed by the experience.

The 335is DCT lacks the M3’s M mode, allowing it to occasionally upshift before reaching redline. It also ignored certain downshift requests, often waiting until it fell to the optimum rpm before making the shift (and not just to protect against over-revving). While it’s a fast, smooth shifter, it seems to do a fair amount of thinking for the driver, something that might be a turnoff to ethusiasts who should consider the manual.

The 335is will be officially unveiled at the New York Auto Show in April. Convertible models will arrive in dealers later that month, while 335is Coupe will show up in June.

Colors are limited to Alpine white, red, blue, silver, Space grey and black metallic. Pricing starts at $50525 for the coupe and $59075 for the convertible. Most of the usual BMW option packages (premium, winter, premium audio, etc) will be available on this models.