Karbonius Composites BMW E46 M3 CSL Program

The E46 M3 CSL will undoubtedly go down as one of the more sought after special editions from BMW’s motorsport outfit. Unfortunately for us in North America, even the sheer opportunity to add a CSL to our garages was denied from the beginning. This omittance left us with two options; pay an exorbitant amount of money for scarce OEM CSL parts or wait for a reputable company to create components for the masses that would mimic the CLS’s hardcore spirit.

As luck would have it, Karbonius is the company that we’ve been waiting for all these years; they’ve built their stellar reputation upon recreating the soul of the CSL and, in some ways, even making significant improvements over the original.

At the core of replicating the CSL’s aura is the fabled carbon airbox who’s visual beauty is only matched by the noise it produces. The Karbonius unit doesn’t just give you both of those in spades, but also leverages technological progress to make their airbox shine above any other CSL-inspired alternative. Modifications to the trumpet diameter, shape, and construction (carbon fiber instead of plastic) all play important roles in increasing airflow and minimizing turbulence within the airbox. The result of this effort is noticeable gains—up to 25hp depending on other modifications and tune—as well as much improved throttle response.

Karbonius’s carbon snorkel is somewhat of an unsung hero in the CSL equation—the airbox certainly steals the show, understandably—but the snorkel is the perfect sidekick. This piece helps channel cool, ambient air from the fog light area directly into the airbox and will directly contribute to the aforementioned power gains.

Karbonius’s obsession with all things CSL is evident with this piece. This engine cover can be seen on the CSL concept, but never made it to production. Made from pre-preg carbon like the other pieces in the suite and adorned with a stainless CSL plate, this cover is the ultimate cherry on top of the proverbial CSL sundae.