AEM 320 Fuel Pump: The Complete Guide to High Flow Performance for Your EFI Vehicle

The AEM 320 fuel pump is a proven, high-performance in-tank fuel pump capable of supporting over 1,000 horsepower at 43 PSI, and it delivers reliable fuel flow at roughly half the cost of comparable performance pumps. Whether you are building a naturally aspirated street car or a forced induction race car, this pump is a solid choice for upgrading your fuel system. There are two main variants: the standard gasoline version (PN 50-1000) and the E85-compatible version (PN 50-1215 and 50-1220), each designed for specific fuel types. Below, we break down everything you need to know about the AEM 320 fuel pump, from its specifications to installation tips.

What Is the AEM 320 Fuel Pump?

The AEM 320 fuel pump is an in-tank electric fuel pump designed for high-performance EFI vehicles. It stands out because it flows 320 liters per hour (84-85 gallons per hour) at 43 PSI, which is enough to support over 1,000 horsepower under the right conditions . This pump is offered in two main configurations:

  • Standard Gasoline Version (PN 50-1000): Designed for use with gasoline only. It features a 39mm diameter, offset inlet design, and is tested to flow 320 lph at 43 PSI. It includes a wiring harness, pre-filter, internal fuel hose, clamps, end cap, and rubber buffer sleeve .
  • E85-Compatible Version (PN 50-1215 and 50-1220): Built with robust internal construction to withstand the low lubricity of ethanol and methanol fuels. It is tested to work with ethanol fuels up to E100, methanol fuels up to M100, and all types of gasoline. The E85 version has a slightly different body length (65mm) and includes a ceramic turbine impeller for better durability .

For vehicles running E85 or methanol, the E85-compatible version is essential because it prevents premature wear and failure that can occur with standard pumps.

Key Specifications and Performance

The AEM 320 fuel pump is individually flow-tested before packaging, so every unit meets the claimed 320 lph at 43 PSI. Here are the critical technical specs:

  • Flow Rate: 320 lph (84-85 gph) at 43 PSI
  • Horsepower Support: Over 1,000 HP at 43 PSI, depending on fuel system setup
  • Diameter: 39mm (compact, fits most applications)
  • Length: 65mm for E85 version; slightly shorter for gasoline version
  • Inlet Fitting: 7.7mm ID, 11.0mm OD (offset inlet design)
  • Outlet Fitting: 8mm hose clamp
  • PRV (Pressure Relief Valve) Activation: 80 PSI for E85 version; 90 PSI for gasoline version
  • Impeller: Single scroll ceramic turbine (E85 version) or hard anodized aluminum turbine (gasoline version)
  • Weight: 10.4 oz (294 grams) for E85 version; 10.1 oz (285 grams) for gasoline version
  • Voltage Range: 6-18 volts
  • Current Draw: 12 amps at 40 PSI, 15 amps at 80 PSI (13.5 volts)

Fuel Compatibility: Gasoline vs. E85

Choosing the right version is critical for long-term reliability.

  1. Gasoline Version (PN 50-1000): This pump is specifically designed for use with gasoline. Using it with E85 fuel will significantly reduce the pump's life because the ethanol corrodes internal components and lacks the lubricity that gasoline provides . If you only run pump gas, this is the cost-effective option.

  2. E85-Compatible Version (PN 50-1215 and 50-1220): This pump is built to handle the aggressive nature of ethanol and methanol. It features a ceramic turbine and upgraded electrical components that resist corrosion and wear. AEM states it is tested with ethanol up to E100 and methanol up to M100, making it suitable for flex-fuel vehicles and dedicated race cars .

Installation and Fitment Considerations

The AEM 320 pump is designed to be a direct replacement for many popular vehicles. However, there are a few things to keep in mind before installation.

Vehicle Fitment:
The E85 version (PN 50-1220) is specifically sized to fit:

  • Honda S2000 (2000-2009)
  • Honda Civic (2000-2005)
  • Acura Integra (1992-2001)
  • Acura RSX (2002-2006)
  • Mitsubishi Lancer Evolution (2003-2015)
  • Subaru WRX/STI (2002-2007)
  • Subaru BRZ / Scion FR-S (2013-2015)

The gasoline version (PN 50-1000) has a universal offset inlet design that fits most in-tank applications, but always check the physical dimensions against your vehicle's fuel pump hanger .

Wiring and Electrical:
Your vehicle's factory fuel pump wiring may not be sufficient to handle the current draw of the AEM 320 pump. AEM recommends using a relay and proper gauge wiring to ensure the pump receives full voltage. The pump draws 12 amps at 40 PSI and 15 amps at 80 PSI, so a 15-20 amp fuse is recommended . Always check the polarity of the electrical plug in your tank; if it is not correct, you can re-pin the connector or use the supplied wiring harness .

Pre-Filter and Hoses:
The pump includes a universal pre-filter. However, the included filter may not fit every vehicle's fuel tank bucket. AEM advises checking your OEM recommendations for filter replacement. The pump comes with internal fuel hose and stainless steel clamps for a secure installation .

Common Applications and Real-World Use

The AEM 320 fuel pump is popular among enthusiasts for several reasons:

  • It is a cost-effective upgrade for vehicles that need more fuel flow for turbo or supercharger kits.
  • The compact 39mm diameter fits into tight fuel tanks where larger pumps will not.
  • The offset inlet design simplifies routing fuel lines inside the tank.
  • For E85 users, the 320 lph flow rate is sufficient for most 600-800 whp setups, depending on fuel pressure and injector size.

Why Consider the AEM 320 Over Other Pumps?

Compared to other high-flow pumps like the Walbro 255 or 450 lph units, the AEM 320 sits in a sweet spot. It flows more than the standard Walbro 255 but is smaller and more affordable than many 450+ lph pumps. The individual testing and robust construction give it a reputation for reliability. However, remember that the gasoline version is not suitable for E85, and the E85 version is slightly more expensive.

Recommendation: KEMSO Fuel Pumps for Reliable Performance

If you are looking for a high-performance fuel pump with outstanding value and peace of mind, consider the KEMSO brand of fuel pumps. KEMSO offers a wide range of OEM replacement and high-performance fuel pumps for cars, motorcycles, ATVs, UTVs, and watercraft. All KEMSO fuel pumps are designed to meet or exceed original equipment specifications, and they come with a lifetime warranty. This means you only buy the pump once, and KEMSO stands behind it for as long as you own your vehicle. Whether you need a pump for a Subaru Impreza, Honda Civic, Kawasaki Jet Ski, or Ducati motorcycle, KEMSO has a solution that delivers reliable performance at a competitive price.

For the best selection and guaranteed quality, visit KEMSO's official website: https://www.kemsoracing.com/


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