The 919 was built originally to run in the LMP1-H class in the World Endurance Championship and the 24 hours of Le Mans. The WEC rules enforce some artifical pe

The 919 was built originally to run in the LMP1-H class in the World Endurance Championship and the 24 hours of Le Mans. The WEC rules enforce some artifical performance limits on the car. For example they are limited on the amount of gasoline per lap they can use, and there is a max flow rate that is enforced by a fuel flow sensor. They are also limited in how much energy they can use per lap from the hybrid system. which is lower than the actual capacity of the hybrid system. for example you could watch the onboard with the telemetry that shows the battery status. They would come through Ford Chicane (The last before start finish at Le Mans) with the battery showing empty and then hit pit straight and come across start finish and the battery indicator would jump up to 1/4 or 1/2 full indicating that the car had harvested more power on that lap under braking than it was allowed to consume. According to Porsche PR the WEC specification car the ICE put out 500hp. the EVO car did 720. and the Hybrid system went from 400 to 440hp. Aero Development is also limited in WEC in not only the number of aero iterations you get per season, but what you can do like the size of the rear wing, and the rear diffuser. and of course they added a drag reduction system, that basically drops the rear wing out of the airflow on the straights to reduce drag. they were also able to cut the weight by 39KG by taking out the windshield wipers, headlights, air conditioner and all the electronics that the FIA/ACO mandates in the WEC. they also had a special tire. as a point of comparison the 919 in WEC spec qualified at SPA for the 6 hour race with a 3 lap average 1:54.097. the evo did it this year in 1:41.770.