When can unofficial be unbelievable? When perhaps the ultimate sports car of its generation can run unrestricted.

The Porsche 919 Hybrid’s racing career is officially over, but its legacy in racing isn’t.

Without any rules or restrictions, Porsche engineers took on the challenge of seeing just how fast its all-conquering LMP1 car, which has won the last three 24 Hours of Le Mans and three FIA World Endurance Championship titles, could go around the 4.352-mile (7.004-km) Circuit de Spa-Francorchamps.

Porsche is planning to run the 919 Hybrid this year in selected non-race events as part of its “Porsche 919 Tribute Tour.”

For this event, Porsche created an ‘Evo’ version of the car. The powertrain remained untouched. However, there were plenty of other areas to exploit.

With a full boost of electric power, the car could run at 8.49 megajoule rather than 6.37 in 2017. There were significant downforce and overall efficiency increases (53 and 66 percent, respectively), thanks to a much larger front diffuser and fixed side skirts.

On the tire front, Porsche noted Michelin’s interest in this chance.

“Michelin was immediately interested to work with a car that produces more downforce than a Formula One car. Keeping the tire dimensions (31/71-18), the target was to increase the grip level significantly. Michelin developed new compounds to deliver the necessary grip with no compromise on safety,” Porsche’s release said.

Stephen Mitas, Porsche’s chief race engineer for the LMP1, outlined the overall opportunity.

“It was kind of an engineer’s dream come true for us,” Mitas said. “Having developed, improved and raced the car for four years, the guys had a very close relationship to it. We all knew, no matter how successful the 919 Hybrid was, it could never show its full abilities.

“Actually even the Evo version doesn’t fully exploit the technical potential. This time we were not limited by regulations but resources. It is a very satisfying feeling that what we’ve done to the car was enough to crack the Formula One record.”

That Formula 1 fastest lap is last year’s pole time, a lap of 1:42.553 set by four-time World Champion Lewis Hamilton in the Mercedes F1 W08 EQ Power+ on August 26, 2017. Of note, the official lap record can only be set in race conditions, and that time is a 1:46.577 set by Sebastian Vettel in the Ferrari SF70H in the 2017 Belgian Grand Prix.

Alas, Neel Jani beat Hamilton’s mark with a best time of 1:41.770. For Jani, getting to drive this car at its theoretical zenith was the capper to an outstanding four years of the LMP1 program.

A top speed of 359 km/h and an average speed of 245.61 km/h: With the #Porsche 919 Hybrid Evo, @neeljani lapped the 7.004 kilometre long circuit of Spa-Francorchamps in 1:41.770 minutes. More: https://t.co/AqxoMbuaY4 pic.twitter.com/OZ3HhjXsYm

— Porsche Newsroom (@PorscheNewsroom) April 9, 2018

“The 919 Evo is brutally impressive,” said the Swiss driver. “It is definitely the fastest car I ever drove. The grip level is at a fully new dimension for me, I couldn’t imagine this amount beforehand. The speed on which everything happens on a single lap with the 919 Evo is that fast that the demand on reaction speed is very different to what I was used to in the WEC.

“We are not only faster than the F1 pole from 2017. Today’s lap was twelve seconds faster compared to our WEC pole position from last year!

“We have had three very intense days at Spa. Today I knew on the very first lap in the morning that the car’s performance was super. The race engineers did a great job setting up the car and the Michelin tires are sensational. A big thank you to Porsche for this experience.”

This lap won’t count as an official record, since it was set in a private session with the car outside homologated regulations.

Enjoy this! https://t.co/RRACP5K1iR

— Andre Lotterer (@Andre_Lotterer) April 9, 2018

But that is besides the point in this instance. Porsche can say its LMP1 car is faster than a Formula 1 car when the regulatory “box” can be opened up. It showcases the car’s ultimate potential.

For more information, check out Porsche’s Newsroom piece here.

Next up for Porsche’s 919 is a demo lap on the legendary Nordschleife in May. That will occur just before the start of the 24-Hours Nurburgring race on May 12.

The car is also set to appear at these events:

• Goodwood Festival of Speed (July 12 to 15)
• Festival of Porsche in Brands Hatch (September 2)
• Porsche Rennsport Reunion VI in Monterey, Calif. (September 26 to 29).