Record Breaker

The SF90 XX Stradale pushes the limits of road-car performance—and blurs the line between street and circuit.

Photo: Record Breaker 1
January 25, 2024

The letters XX have a magical connotation at Ferrari. Since 2005, the company has used this designation for a series of very special track-day machines: the Enzo-based FXX, the 599 XX (based on the 599 GTB Fiorano), and the FXX-K, which was derived from the LaFerrari. There are also improved Evo variants of each model, all offering new technologies that, in many cases, were applied to Maranello’s road cars.

Only a few dozen examples were produced per model, and without exception they are lighter, more powerful, faster, and more expensive than their road-going counterparts. Although they are not race cars in the normal sense—as they were not homologated by the FIA and are therefore not eligible to compete in FIA series—they were designed exclusively for track use (at dedicated, Ferrari-run events) and lack a license plate.

The SF90 XX breaks that tradition; it is a proper street car. This makes it more usable and—not insignificantly—allows Ferrari to sell many more. In total, 799 SF90 XX Stradales and 599 XX Spiders will be produced. All 1,398 cars have already been sold to the company’s best customers (i.e., those with at least five Ferraris already in their garage). Not included in the purchase price—which started at roughly €790,000 for the Stradale and €870,000 for the Spider, about 40 percent more than the regular SF90s—is access to those VIP track days.

Photo: Record Breaker 2

Ferrari says the SF90 XX is an experiment with the XX label, but there’s no question those chosen buyers will receive something special. To start, only the doors and roof are interchangeable between SF90 and XX. The latter is nearly a half-foot longer, taking it to nearly 191 inches. The extra length resides mainly in the rear, with the aim of placing the upright wing far back, allowing the wind to reach it as undisturbed as possible. This is Ferrari’s first fixed rear wing since the F50 of 1995.

The aero package has been further shaken up with slots atop the wheel arches and a completely different front end with more inlets and outlets to separate and direct cool and warm air. All told, the SF90 XX delivers 1,168 pounds of downforce at 155 mph, which is twice as much as the normal SF90. The new model is also much more ferocious-looking, rugged, and intimidating than the original.

You might be surprised to learn the XX only weighs 10 kilograms, or around 22 pounds, less than the regular SF90. That’s not much, but makes sense when you learn Ferrari actually saved some 66 pounds via thinner sheet metal, different interior panels, and lighter seats. But pounds were added back courtesy of larger brakes, the new rear wing, and especially the aluminum legs on which that wing sits.

Photo: Record Breaker 3

Test driver Raffaele de Simone set a new street-car lap record at Fiorano in the SF90 XX Stradale.

The XX’s power increase is similarly modest, with output rising by 30 hp to 1,030. The 4.0-liter twin-turbo V8 features slightly higher compression (9.54:1 versus 9.50:1) due to different pistons, which adds 17 hp and 3 lb-ft of torque. The hybrid system accounts for the rest of the increase. While the SF90’s two electric motors on the front axle (capable of 135 hp each) and the single one between V8 and gearbox (218 hp) remain unchanged, their combined output has risen 13 hp to 233 hp, due to the car’s 7.9-kWh battery being better cooled and therefore able to deliver more power.

The hybrid powertrain’s total torque figure also remains unchanged, at 663 lb-ft, since the eight-speed dual-clutch gearbox cannot handle more pulling power. (The gear ratios are the same as in the regular SF90.) However, it does receive the Daytona SP3’s shifting software to improve the engine’s sound, and further aural enhancement is provided by a redesigned “hot tube” that connects engine bay to cabin. After all, more speed is nothing without a better experience.

AS BEFITS THE XX NAME, Ferrari invited the press to drive the SF90 XX Stradale on the Fiorano circuit. The first session is wet, but still allows me time to gain plenty of impressions.

Photo: Record Breaker 4

First, unlike previous XX models, the SF90 XX is far from a stripped-down race car. Instead, the occupants are treated to air conditioning, infotaintment, and fine carbon-fiber bucket seats with an adjustable backrest (which are much better than those fitted to the regular SF90).

Second, the XX’s suspension is tighter. Roll stiffness has been increased by ten percent, and Ferrari has fitted the manually adjustable Multimatic dampers found in the regular SF90’s optional Assetto Fiorano package. (The magnetorheological dampers found on the normal SF90 are optional on the XX, and allow the use of Ferrari’s front axle lift system.)

Even on damp asphalt, the XX’s nose still dives quite a bit during braking, although its tail seems to rise less, making the rear end quieter and more stable when steering. Where the regular SF90’s front and rear axles somewhat feel as though they’re working against each other during turn-in, the XX’s axles help each other, making the newer car less of a handful.

Photo: Record Breaker 5

Also assisting is the latest version of the brilliant ABS Evo brake-by-wire system. On the damp track, I can still brake deeply to the apex and the XX dutifully follows the direction of the steering wheel. The brake pedal has a short stroke yet still allows excellent modulation; it’s sublime.

The steering delivers a good sense of what’s happening with the front wheels. Its weight increases when the nose is pressed down, then lightens again when throttle is applied. The XX does not have the very light, hyper-direct steering of the F8 or 488, instead offering a balanced steering feel for quick but measured reflexes.

My right foot becomes more important than usual when exiting a turn, as the XX offers 30 “power boosts” when in Qualify mode. During a boost, the powertrain delivers its maximum output of 1,030 hp for up to five seconds. (Without a boost, the XX produces 1,017 hp.) This drops about 0.25 second from a lap of Fiorano, during which seven boosts are deployed.

Photo: Record Breaker 6

The driver doesn’t have to do anything besides flooring the gas pedal. Then, one by one, the 30 yellow bars disappear from the digital instrument cluster. You can also “save” boosts courtesy of regeneration—just like in Formula 1 before starting a flying lap.

I CAN ATTEMPT THESE LATER in the day, once the track has dried out and the mechanics have fitted Michelin Pilot Sport Cup 2 tires in place of the morning’s Bridgestone Potenza run-flats. After three laps, a data engineer opens up the telemetry and overlays my best lap with that of Ferrari test driver Raffaele de Simone.

With the SF90 XX, de Simone set a new street car record at Fiorano: 1:17.3, when fitted with carbon-fiber wheels and fierce Cup 2R rubber, some 1.4 seconds faster than an SF90 Stradale Assetto Fiorano. (While that’s a big gap when comparing road car to road car, previous XX models were several seconds faster than the street machines from which they were derived.) Interestingly, he achieves this feat in CT-Off mode, in which traction control is disabled and stability control intervenes much later. ESC Off mode, de Simone notes, is only for when you want to drift.

Photo: Record Breaker 7

So where is de Simone faster? The data engineer walks me through my lap to demonstrate, as I re-live the experience.

At the first braking point, the XX’s nose dives deep and the front end responds razor-sharp to the steering wheel. The rear end is agile and pushes the nose in—partially. The nose is still loose, but less so than with the regular SF90.

My speed at the apex is only a few km/h slower than that of the Fiorano hero. But then de Simone coasts before putting the gas down with a velvet foot, gently building up full throttle and maintaining traction. On the telemetry screen, his throttle trace is a gradually descending line.

Photo: Record Breaker 8

My trace is a vertical line, more likely to go all the way to the bottom. The abrupt acceleration that follows is more than the rear tires can handle, and shows up as hefty outliers in the graphs of both throttle and steering as I lift and countersteer a few times to stay on the track. De Simone has already pulled ahead.

Traction in slow and medium-speed corners is tricky with so much power, but on the fast stretches the XX has no such problem. The test driver’s speed line rises well above mine, and for the next turn he brakes later and harder, so his braking zone is shorter and he continues at speed longer. Looking at the graph, his every movement of the wheel and pedals appears flawless.

I lose another few tenths, and in the next fourth gear combination he pulls ahead even further. Where I give a short burst of gas between corners, de Simone accelerates longer. Our steering input is the same, so the difference is all to do with confidence and talent.

Photo: Record Breaker 9

Then it’s hard acceleration into fifth gear toward the right turn onto the bridge. The bangs and reactions of the eight-speed transmission are even more ferocious because of the new shifting software; shifts are super-fast, with fierce shocks and the rough sound of a pneumatically operated racing gearbox. Then it’s time to brake hard and deep and drop two gears to reach the apex.

I arrive there at 71 km/h [44 mph], with de Simone at 68 km/h. That initally sounds hopeful, but it is not. Where I get understeer after releasing the brake pedal too early and have to wait to get on the gas, he has already accelerated away. As a result, my speed line dips below his once again.

At the top of the bridge, the car almost takes off, and on the telemetry I can see the V8’s revs spike. On this short stretch, the XX hits 180 km/h [112 mph] just into fifth gear, then I have to brake quickly down hill into a right-hander. Our graphs show similar waves, but de Simone’s are all more refined and peak higher.

Photo: Record Breaker 10

I steer into the off-camber turn, and the car turns in with light oversteer. The XX is calmer here than the regular SF90, its rear end more stable. I countersteer into the apex then powerslide to the outside curbstones, using the full width of the track. The key is to keep the slip angle small to avoid losing forward progress, and Ferrari’s Side Slip Control electronics help tremendously.

Any passenger would credit me with de Simone’s abilities, because SSC’s interventions can’t be heard and are barely felt. Perhaps the only thing Ferrari’s wonderfully precise driving aids lack is a multi-position traction control setting; currently, it’s all on or all off.

After dropping down a short straight, I drop two gears for the hairpin. The slowest point of Fiorano is tackled at barely 40 km/h [25 mph] and I can feel the electric motors on the front axle pulling the nose through the corner, with the outer wheel doing more work. In fact, this is the only place on the track where I really feel the all-wheel drive.

Halfway through the hairpin, my telemetry graph undulates up and down. With frowning eyebrows, the engineer asks what was going on here.

“Showboating for the video,” I reply, honestly, as in steering with the throttle to induce camera-friendly oversteer and wheel spin. (It’s hopelessly slower than the ideal way, but fun.) His smile reflects a lack of understanding: “Less show and more go,” he advises for a faster time.

Next comes the fastest corner on the circuit, a right-hander taken high in fourth gear. The Ferrari man hits 192 km/h [119 mph] there, while I peak at 176 km/h [109 mph]; he arrives faster and dares to get on the gas sooner. The XX enters this turn significantly harder and more calmly than the regular SF90, then carries this speed and poise out again as the downforce does its thing, allowing me to get back on the gas earlier without fear of the rear end getting light.

“Let the wing do its job and have confidence,” the engineer advises me. “The rear end really stays put.”

Because of his higher exit speed, de Simone picks up time on the short straight to the final corner, a long third-gear 180. Once again, cornering is fighting oversteer, as the semi-slick Michelins can’t handle it. As so often is the case with modern supercars, the rubber is the limiting factor. With two fat black stripes following me out of the turn, my XX experience comes to an end. It is time for the debriefing.

Comparing my lap time with the record is (fortunately for me) not possible. To avoid exceeding local noise limits, we had to cruise down the front straight. A fine excuse, but the fact that a well-meaning amateur can reasonably follow Ferrari’s top test driver in some corners in this monster of a machine is telling.

This is a world-class performer. A 1,030-hp poster child should be almost terrifying, but the car doesn’t give that feeling. Instead, the XX is easier to control than the regular SF90, but still impetuous and combative. The electronics work superbly, letting me drive over the limit undisturbed while still maintaining a safety net. And with its tighter suspension and better aerodynamics, it manages to create a level of confidence that reminds me most of the ego boost delivered by the magisterial 488 Pista, a car that lets its driver rise far above him or herself on the track.

The SF90 XX Stradale pulls off that same trick, and, unlike its predecessors, doesn’t require access to a super-exclusive XX Program track day. Of course, it’s easy to shoot holes in the purity of this SF90, because, compared to its predecessors, this street version is much less extreme, not a “proper” XX. It is, however, unquestionably an XXL supercar.

Also from Issue 212

  • Portofino M
  • Dino 246 GT restoration
  • Eugenio Bodda interview
  • 7,500-mile 458 Spider road trip
  • FCA Coppa GT winner
  • F1: Conclusions
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