This is a pretty nifty race modification. The mechanical fuel pump is running on a 6 throw crankshaft driven at cam speed. This way instead of having a halibrand style injection that feeds all cylinders continuously, fuel is only shot into the intake tract when the air velocity is high providing much better fuel atomization. This would also prevent fuel pooling behind the intake valves, and increase fuel economy.
Still not as good as a piezoelectric injector though like the Sauber is running 8 of.