A swirl pot is a unit which sits in the petrol tank on the bottom . the fuel feed comes out of the pipe on the tank which comes from the swirl pot. Think of it as a holder of fuel which always has a constant supply to the pump . Its to prevent a surge although u can still get a surge if ur unlucky . Im no pro but thats what it does. Use an accumalator aswell , think this prevents any air in the fuel line .