The surge tank is an important part of any turbocharged fuel system because it stops your engine from starving fuel. The fuel surge tank ensures that your engine gets the amount of fuel it needs for high power output.
This is important in demanding conditions such as drifting, drag racing and track days. A situation like this means that your fuel system will be exposed to high levels of lateral acceleration loads for an extended period of time.
The fuel surge tank means that the fuel pump always gets fuel the same way regardless of gravity.

How does it work?
The fuel surge tank works on the principle that two flows produce a stable fuel supply under any conditions. By using the flow in the fuel system, the surge tank will be constantly filled with fuel. The lift fuel pump will supply fuel from your fuel tank while excess fuel returned from the fuel pressure regulator is circulated back to the pressure tank. This means that even under low fuel levels or extreme conditions, there will still be a constant supply of fuel due to starvation and reduced fuel delivery from the fuel tank or fuel cell.

Why buy a fuel surge tank?
A pressure regulator keeps your pump pumping fuel, never having to worry about starving your engine of fuel. Providing stable fuel levels increases your chances of utilizing all the power your engine has to offer. If the fuel supply is suddenly interrupted, there is a good chance that your engine will take a lot of damage, especially at high power output and high revs.