Powertrain
INTERNAL COMBUSTION ENGINE
The combustion engine is a modern V8 5.0L 32-valve double overhead camshafts (DOHC) and dual variable timing independent (Ti-VCT). To ensure optimal weight distribution and a lower center of gravity, the engine is positioned entirely behind the front track axle in a rather low position, thanks to the dry sump lubrication. The engine is supercharged by a 2.9L twin-screw compressor that offers a progressive increase in torque, even at low revs, at a constant pressure of 11 PSI. The compressor is equipped with a liquid intercooler with 2 radiators located in the side air intakes of the front bumper. The combustion engine alone delivers 750 horsepower at 7,000 rpm and 878 Nm of torque at 4,400 rpm. The final assembly of the internal components of the engine is carried out meticulously, by hand, in Italy. The engine’s electronics management is entrusted to a MOTEC ECU, and is supported by a software package that was specially developed by Puritalia and a proprietary OBDII control unit that comply with EURO 6 environmental regulations.
ELECTRIC MOTOR
The advanced axial flux electric motor is supplied by Yasa and produces up to 370 Nm of torque and 215hp of peak power at a weight of just over 25Kg. The engine was integrated by Puritalia directly on the rear differential, thanks to its extremely compact diameter of 305mm and axial depth of 106mm. In this configuration, the torque delivered by the electric motor bypasses the gearbox gear ratio and acts directly on the rear wheels through the final ratio only. This configuration is optimal to transfer the enormous torque provided the electric motor to the wheels, that is always fully available from 0 to 7,000 rpm. The control of the electric motor acts alongside the automated gearbox control AMT, increasing the thrust during the opening of the clutch necessary for gear shifting. This results in continuous acceleration – even during gear changes. Puritalia engineers also incorporated an electronically managed clutch that disengages the electric motor from the differential in specific usage conditions to avoid dragging when it’s not needed. To ensure the performance of the electric motor even during the most intense periods of use, the engine temperature is constantly monitored and managed by a cooling system that provides a flow of up to 20 liters / hour of dielectric oil.
BATTERY PACK
Puritalia Berlinetta has two lithium-iron-phosphate (LiFePO) battery packs, entirely designed and built by Puritalia, that guarantee a total capacity of 5.2 kWh; the main battery pack is positioned under the trunk area while the secondary is in the area behind the seats, in a low position for the car’s center of gravity. The two 700V battery packs are dynamically managed in parallel; they’re used individually in normal conditions, and in combination (to raise the current up to 230A) when the Puritalia eMozione© function is activated, in order to provide the maximum power and torque. A complete charge of the battery packs requires just over 3 hours via an electric socket and the special charger supplied with the car. The batteries can also be charged during braking and while coasting through a special function that can be activated by the driver. Both battery packs integrate the BMS (Battery Management System) and cooling management system.
COOLING
A great deal of attention was given to studying heat diffusion and resulted in the design of the appropriate cooling systems, because, contrary to what one might think, the electrical components of the hybrid powertrain generate as much heat as a combustion engine. The air intake on the hood leverages the air depression to facilitate the expulsion of heat from the engine compartment. The cooling of the powertrain is carried out by 10 radiators positioned near the air intakes on the front and rear bumpers and the flat bottom of the car. These radiators provide for the cooling of the combustion engine, the intercooler, the transmission, the differential, the electric motor, the AC inverter, and the battery packs.