It's mostly a massive wing and diffuser.
It’s kind of astonishing that Alfa Romeo hasn’t run some sort of racing program with the 4C, it’s mid-engined, lightweight, carbon fiber sports car. But an Italian hillclimb racer has taken the initiative and developed his own 4C race car.
As you can see, it’s a Frankenstein’s Monster of a thing. Details on it are scarce, but it seems to be based on the same carbon fiber tub chassis as the 4C road car. The bodywork, on the other hand, appears to have been altered considerably, particularly the elongated rear. But it has been done so subtly you would have stand the car next to a standard one to see the differences clearly.
Less subtle, though, are the aero devices. In fact, they’re about as subtle as a Saturn 5 rocket launch. The rear wing and diffuser are utterly preposterous but absolutely necessary on hillclimb courses that can change from tight and twisty to fast and flowing three times in a mile.
There’s a lot of power to keep on the ground, too. The 4C’s usual 1750cc, turbocharged four-cylinder engine remains in place, but the output has nearly tripled to 600 horsepower (448 kilowatts). Massively wide rear wheels put the power on the road (I’m convinced the fender wells are smaller than standard) and the shotgun exhaust makes it sound like a swarm of bees engaged in an artillery barrage.
This absolutely insane car is the work of Marco Gramenzi, a many-time Italian hillclimb champion who used to race a screaming Alfa Romeo 155 Ti DTM car. Apparently, Alfa Romeo gave its blessing to the 4C, and a number of its engineers were involved in the design and build process.
Gramenzi debuted the 4C at the start of 2016 season in April. In this video, shot last weekend, he appears to be driving a little bit tentatively - presumably the car is still in the testing and development stage. Once it’s fully sorted, expect Senore Gramenzi to assume his usual position well ahead of everyone else.