While a fuel pump might seem like an upgrade only for fully built cars with huge turbos, even those of us pushing the limits of stock frame turbos may have something to gain. Fuel pumps, like all fluid pumps, have a maximum flow capacity and an optimal efficiency window. Ideally you want to choose a fuel pump that never has to operate outside of its efficiency range on your particular setup. The stock fuel pump on most FWD Volvos will support an absolute maximum of somewhere around 300 bhp. This means that even a tuned car with a stock turbo may be experiencing the effects of a fuel pump operating outside of its optimal efficiency window.