Few cars on the planet can match the 1036bhp power output of the Ferrari FXX K.

From inside the cabin there's a rugged simplicity to it, stripped down to the bare essentials to squeeze out the extra 101bhp over the LaFerrari it’s based on.

I’m examining the car from the passenger seat at the start line of the hillclimb at Goodwood. My driver is Pat Blakeney, the operations manager for Thruxton circuit, and he’s a man under pressure.

Pat has driven for Ferrari at events for the past 15 years and now he’s behind the steering wheel of the FXX K, leading the lineup on the final run of the opening day of the Festival of Speed.

The morning run ended in disappointment. The FXX K’s battery and KERS system didn’t agree with the stop start nature of the procession towards the hillclimb, so the car could only limp up the hill and its weekend participation was put into doubt.

Ferrari’s technicians worked throughout the day to make sure it was ready for the final session, and at one of the standout spectator driving events of the year, the team was desperate for the car to put on a good show.

Fast forwards to the start line, and I’m sat next to Pat as various technicians lean in through the window offering advice. All the while he’s very aware that he’s driving one of just 40 €2.5m FXX Ks, and it isn’t his. And there’s a McLaren P1 GTR on the same run.

No matter the condition of the battery, this won't be a flat-out run, though. As much as Ferrari wants the car to steal the show, it also needs it back in one piece to return it to the owner who leant it to them.

Strict orders are given to Pat to offer the battery as much chance as possible of working to its full capacity. It is crucial not to turn the engine on and off too many times, otherwise it will drain itself and the car would “only” be relying on its 848bhp petrol motor.

The display shows an 80% charge for the battery - enough to run the full 1036 horses - and a technician leans in: “Traction control off; I want to see smoke”.

Qualifying driving mode on the centre console is selected to ensure maximum power for the short run, and Track mode on the steering wheel turns everything off.

The marshal gives the all-clear and there’s barely time to register the smoke billowing from the tyres before I’m pushed deep into the back of the bucket seat through the opening straight. The pull is sensational, and the engine screams out close to the full 9200rpm at the red line before a quick shift up on the seven-speed twin-clutch gearbox changes the tone.

There was a strict caveat to appreciate before the run; the car is in a completely alien nature. Designed for long and arduous track days, the stop start run to the hill and then the short 60sec blast is a far cry from the natural habitat of the FXX K.

To compensate, it’s on wet weather tyres; the much softer compound being preferred to slicks as the car doesn’t have the time to generate the significant temperature required to run on slicks.

Those rear wet weather tyres still squirm around looking for grip through the opening two corners in Track mode with everything off. That mode still allows a taste of the new aerodynamic capability of the FXX K, however. It generates 540kg of downforce at 133mph – double that of the LaFerrari. And you really feel it at times.

A quick flick of the switch and the car goes back into Race mode from Track, and the added traction control helps Pat push the car even further.

I think I hear him shout something but the only thing audible from inside my lid is the delirious roar from the engine behind us.

The electric motor takes absolutely nothing away from the thunder of the V12 naturally-aspirated 6.3-litre petrol engine behind our heads. And with the silencers on the exhaust from the LaFerrari now gone, it delivers an even more raucous noise than its sibling.

Charging up the final straight to the finish, a quick glance at the speedo shows the car kissing 200kph (125mph) and an exhilarated - and relieved - Pat allows himself a cheer as we cross the line.

Pat's run up the hill last year was in the LaFerrari and he says that the difference between the two cars is huge. The massive weight saving in the FXX K and the improved aerodynamics put it in a different league entirely, he says, as we reach the end of the run.

We stop at the top of the hill and get out. Pat, beaming, turns and says “I can die happy”.