How does a swirl pot / fuel surge tank work?

How does a Fuel Surge Tank work?

One of the most frequent questions we get is, how does our Fuel Surge Tank / Swirl Pot works, and how to apply it to make a stable fuel system for high power output in race cars of various kind.

We have put a lot of time explaining this over e-mail and phone calls, trough links and trying to refer to Google. What we discovered was that the guides available were quite outdated and often the flow charts were made in the last millennium, in refined programs such as Paint or even worse.
To make it easier we will guide you trough some of the basics, with modern technology, and good-looking and easy-to-understand graphics.

What is the purpose of a fuel surge tank?

By using a Fuel Surge Tank / Swirl Pot, you ensure that your engine always gets the amount of fuel that´s needed for high power output in demanding conditions e.g. drifting, drag racing, track days. In conditions were your fuel system will be sustaining high lateral acceleration load for an extended period of time.
A Fuel Surge Tank / Swirl Pot ensures that the fuel pumps constantly receive the same access to fuel, regardless of the action of g-forces in constant or variable direction.

How does the fuel flow?

To understand how the fuel flows in a modern fuel system with an integrated surge tank is the cornerstone in understanding how to use a Fuel Surge Tank / Swirl Pot, and how it all fits together.
There are several possible setups. We here show how to build a proper system based on our top quality products, this is the basis, the variations are endless, even if they are all based on these grounds.

Flow chart for FST with external fuel pumps:

Click on image for high resolution .pdf!
How does a fuel surge tank work with external fuel pumps?

Flow chart for FST with internal fuel pumps:

Click on image for high resolution .pdf!
How does a fuel surge tank work with internal fuel pumps?

How does it work?

By using the flow in your fuel system the surge tank will be constantly filled with fuel. The lift-fuel pump will provide fuel from your fuel tank or fuel cell while the excess fuel returned from the Fuel Pressure Regulator is circulated back into the surge tank. These two flows generate a constant supply of fuel under any conditions, even if the fuel delivery from the fuel tank or fuel cell is reduced due to starvation during low fuel level or extreme conditions.

Our Fuel Surge Tank / Swirl Pot works as a buffer providing an inexpensive insurance policy to protect your engine and minimizes the risk of fuel loss.
Providing a constant level of fuel increases your chance to take advantage of all the power your engine delivers. If the fuel supply suddenly fails, there are high chances that your engine will take a lot of damage, especially at high power outputs and at high rpm´s.

The combination of products creates the fuel system…

Knowing which products to choose has never been easier. We are proud to offer a wide selection of high quality products for your fuel system, whether you´re vehicle has 200 hp or 2000 hp.
All our products are designed and manufactured to maintain the highest quality and live up to the reputation we have gained in the market worldwide.

Our product line ranges from a Universal Bracket for fuel pumps and fuel filters, to one of the absolute best Fuel Pressure Regulators you can find on the market today. We also offer unique FST-kits that are ready to adjust your fuel system , our FST in combination with the most commonly used fuel pumps from major manufacturers such as Bosch, Walbro & Deatchwerks.

Our range of fuel parts

Click on the images for product information.

Which fuel pump should I use?

The number of fuel pumps on the market has increased significantly in recent years. They have different characteristics, different flow per hour and are designed for a more precise power output than earlier models/versions. Choose carefully and find out as much as possible about the fuel pumps – For more information, use the manufacturer´s websites or contact your local dealer.
Which fuel pump should I use in combination with a swirl pot?
We have chosen to design our Fuel Surge Tank kits to work with some of the most common used fuel pumps on the market, fuel pumps that we know work satisfactory and are of good quality. We offer complete kits designed for single or dual use of Bosch 040, Walbro GSS341 & GST450 and Deatschwerks DW200 & DW301. We also offer a complete kit for using one our two externally mounted Bosch 044.

Did you find this guide usefull?

Please send us your feedback and input to