The large square tank is where the engine's breathers terminate. Ethanol fuel creates a lot of liquid in the blowby gasses and a large volume breather tank is needed. The engine oil filter is forward of the tank.
If you have ever tried to mess with a late model CANBUS equipped car when modified for racing you can appreciate the idea of a completely user-configurable management system. Even with sophisticated tuners with a lot of technical support, OEM system can drive you crazy when used for racing.
Ever disconnect the radio antenna and have the car only work intermittently afterwards? Welcome to the world of trying to race a late model car with the stock ECU.
The PDM cleanly, simply and reliably handles a race car's power management replacing tons of switches and relays. It has smart functions as well like user defined activation logic. All race cars should have them!
To keep the engine fed under high cornering G-Loads a Radium FCST (Fuelcell Compatible Surge Tank) internal surge tank is used. This is one of the most sanitary ways to safely integrate a surge tank into a race car fuel system with no external mounting of pumps or tanks needed!
The 2.2-liter FCST has one Walbro 450 LPH pump as a lift pump to feed the surge tank with two Walbro 450 LPH pumps feeding the engine from the surge tank.