Fuel Pump Flow Guide

Using the guides below you can quickly estimate your required fuel flow based on the following.

• Fuel - Petrol or E85

• Desired Boost pressure / Required Rail pressure

• Target Power (KW)

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General Rules

• The return line size needs to be equal to the supply or ideally, larger than the supply. This is because the return line needs to return fuel with as little restriction as possible.

• The longer the line, the larger the restriction. 

• The larger the pump, the larger the line should be.

Remember

1. Base rail pressure is normally 300kpa - 3 Bar - 43.5Psi

2. Boost pressure is added to your base rail pressure  43.5psi + Boost = Target kpa 

3. The following guide does not factor bends, banjo's, or any other restriction. 

4. Pump voltage is assumed 13.5V-14v. 10awg-12awg is typical for larger pumps.

5. Assuming you've sized appropriatley, If your fuel pump fuse or relay is melting this indicates

   1. Low voltage caused by,​

      1. Incorrect wire size​

      2. Incorrect Voltage - too low

      3. Poor earth

   2. Excessive pump head pressure caused by,​​

      1. Incorrect line size​

      2. Blocked or restricted supply or return

      3. Pressurised surge tank caused by in-tank pump too large for return line size​

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We made this chart for Aus Dyno ❤️ We're not responsible for your fuel system not working after following this guide. We are if it did work!! #ausdyno