Ferrari’s famously unhinged ‘XX’ series of cars – which count 2005’s FXX through 2008’s FXX Evo, 2010’s 599XX cars and the wild LaFerrari-based FXX-K of 2014 – have always been tethered to a racetrack. For the first time, Ferrari has revealed a pair of expletives that are road-legal.

Welcome, one and all, to the delightfully deranged duo of the Ferrari SF90 XX Stradale and the Ferrari SF90 XX Spider. In a team-up Marvel would be proud of, Maranello has matched the worlds of its Special Series cars and XX programme together for reasons… that are best left unexplored.

What we can explore are the places Ferrari has ventured to extract yet more magic from the already extreme ‘regular’ SF90.

That car’s herculean 3.9-litre turbo V8 was the starting point, and for the XX application benefits from polished inlet and exhaust ducts, a tickle to the compression ratio via new pistons and “specific machining of the combustion chamber”.

We’re told Ferrari binned the secondary air system, which cut 3.5kg of engine mass.

So it’s lighter, and noisier too, Ferrari explaining it as “a wonderfully rich explosion of iconic Ferrari V8 sound”. The tube from the intake plenum has been redesigned and repositioned – indeed the word ‘raucous’ is used – for better harmonic clarity. Screamy, then.

The three electric motors (one betwixt engine and ‘box, two on the front axle) get a power bump via Ferrari’s “patented extra boost vehicle dynamics logic”.

Though, if the fury of a combined 1016hp (1030CV) - up from the 'normal' car's 1000hp - feels a bit… XX, Ferrari assures us both SF90 XXs will go around 24km on e-power alone, up to 135km/h.

Oh, and there’s new gearbox mapping for the eight-speeder, pinched from the Daytona SP3 that also promises better overrun noise.

Shall we talk aero? Thine eyes will confirm what works have been put upon ye mighty XX, and the headline is… “a palpably faster lap time at Fiorano”. That time has yet to be confirmed, but it’ll be achieved via the SF90 XX’s downforce - double that of the regular car.

Literally from the ground up, Ferrari tweaked the underbody, the side louvres, and fitted a new larger front splitter and wider diffuser, a pair of ‘S-ducts’ on the bonnet and blown ducts on the bumper. The body itself proudly wears its racing pedigree, we’re told, with a subtle but noticeable reprofiling of Flavio Manzoni’s original design.

(The SF90 XX Spider features a flying buttress said to “seamlessly meld” with the car’s ‘arrow’ theme, while the roof itself is a retractable hard-top, able to open in 14secs at up to 45km/h.)

All of it peaks at the SF90 XX’s headliner: a huge, fixed rear wing, adjustable for either low drag or high downforce. And there is plenty of it: 315kg of max pressure at 250km/h on the rear, while the front benefits from a maximum possible 325kg at top speed.

Of course, speed. Ferrari reckons both SF90 XX Stradale and Spider will go from 0-100km/h in 2.3s, 0-200km/h in 6.5s for the Stradale (6.7s for the Spider), and a top speed of 320km/h for both. Again, both improvements on the regular road car numbers.

Attempting to harness such velocity will be electronic Side Slip Control 1.0, which takes in the various systems including torque vectoring and energy recovery. The 296 GTB’s ABS EVO controller makes an appearance here for better brake distribution, while the 6W-CDS sensor is said to deliver more data than before.

Wind up the ‘Qualifying’ mode on the eManettino, and you’re treated to additional boost in short bursts, “at the critical moment when the car is exiting a bend”. Only in a Ferrari XX car is cornering described as being ‘critical’.

You’re even told how many boosts you have left from a maximum of 30. Just like in Mario Kart, you will want to use them wisely.

Speaking of karts, Ferrari reckons the XX offers a nine per cent improvement in high speed handling conditions, while the roll rate has been reduced by 10 per cent for better control. Massive brakes, of course.

A car that wears its motorsport so prominently on the outside bears it inside, too. Alcantara adorns the dashboard, there's carbonfibre, and racing seats that are 1.3kg lighter than the regular Stradale’s single-piece items.

Ferrari will build 799 versions of the SF90 XX Stradale, and 599 of the SF90 XX Spider, with both representing “the latest and most extreme example of a concept of special versions, which pushes the performance of Ferrari’s road-going models to new levels”. Be afraid.

STORY Vijay Pattni