255 Liter Per Hour Fuel Pump High Pressure/Volume E85: The Ultimate Guide for 800+ HP Builds

If you are aiming for 800 horsepower or more on E85, a 255 liter per hour (LPH) fuel pump is the absolute minimum starting point, and in most cases, it will be insufficient for sustained high-power operation. Due to the lower energy density of ethanol, E85 requires roughly 35-45% more fuel volume than gasoline to produce the same horsepower . A 255 LPH pump, when properly engineered for E85, can support approximately 650-750 horsepower on a naturally aspirated engine or up to 500-550 horsepower on forced induction when using gasoline; however, its effective support for E85 at 1000 horsepower is typically limited to around 400-450 horsepower . For reliable 1000+ horsepower on E85, you will almost certainly need to step up to pumps rated at 450 LPH or higher, such as the Walbro 450 LPH or 525 LPH units . This guide will explain exactly what a 255 LPH E85 pump can and cannot do, how to choose the right one, and what supporting modifications are essential for success.

Why 255 LPH Is Often the Minimum for E85 Applications

The fundamental challenge with E85 is its lower energy density. Ethanol contains about 85% of the energy per gallon compared to gasoline, meaning your engine must burn significantly more fuel to achieve the same power output . For a 1000 horsepower target on E85, you need a pump that can deliver at least 800 LPH at system pressure, which is far beyond the capacity of any single 255 LPH pump . However, a high-quality 255 LPH pump remains a popular choice for moderate builds (400-600 hp) and as a reliable upgrade for stock fuel systems.

Key specifications for a 255 LPH E85 pump:

  • Flow Rate: 255 LPH (67 US GPH) at 43 PSI and 13.5 volts .
  • Operating Pressure: Capable of maintaining flow up to 110-112 PSI, which is critical for forced induction applications .
  • Ethanol Compatibility: Must be explicitly rated for E85. Look for pumps with Viton seals, stainless steel internals, and anodized aluminum components to resist ethanol corrosion .
  • Current Draw: Typically draws 8-12 amps, requiring upgraded wiring to prevent voltage drop .

The Role of 255 LPH Pumps in Real-World E85 Builds

While a single 255 LPH pump cannot support 1000 horsepower on E85, it can be a building block for higher-output systems. Many builders use two 255 LPH pumps in parallel or in a staged configuration to achieve the necessary flow. For example, dual 255 LPH pumps can deliver over 500 LPH combined, which is sufficient for many 800-900 hp E85 applications . However, this approach adds complexity, cost, and potential failure points.

For single-pump setups, a 255 LPH pump is best suited for:

  • 400-600 hp naturally aspirated E85 engines. This is a common upgrade for street cars with moderate power goals.
  • Carbureted applications. Carbureted engines can often use a 255 LPH pump to support up to 750 hp on E85 because they operate at lower fuel pressure .
  • As a direct replacement for a failing stock pump. Many aftermarket 255 LPH pumps are drop-in replacements for common OEM pumps, making them a simple upgrade .

Essential Supporting Modifications for a 255 LPH E85 Pump

A high-flow fuel pump cannot operate in isolation. Even the best 255 LPH pump will fail to deliver if the rest of the fuel system is not upgraded. Here are the critical supporting components:

  1. Upgraded Fuel Lines:

    • Factory fuel lines are often too restrictive for high-flow E85 systems. For 255 LPH pumps, you should use at least 3/8-inch (AN-6) or larger lines. For multi-pump setups, 1/2-inch (AN-8) lines are recommended .
    • Use E85-compatible hoses, such as PTFE-lined or stainless steel braided lines, to prevent ethanol degradation .

  2. Proper Fuel Pressure Regulation:

    • E85 requires a return-style fuel system with a high-quality fuel pressure regulator (FPR). Set the base pressure to 43-50 PSI (3 bar) for most applications .
    • For forced induction, use a rising-rate regulator that increases fuel pressure with boost to maintain consistent flow.

  3. Electrical System Upgrades:

    • A 255 LPH E85 pump draws 8-12 amps at 13.5 volts. Factory wiring is often too thin, causing voltage drop that reduces pump flow .
    • Install a dedicated relay kit with 10-gauge or larger wiring directly from the battery. Use a fused power supply to protect the system .
    • Ensure your alternator can handle the additional load. A 100-amp alternator is usually sufficient for a single pump, but higher-output alternators may be needed for dual pumps or other high-draw accessories .

  4. Filtering and Installation:

    • Use a 10-micron pre-filter before the pump to protect it from debris, which is common in E85 due to its hygroscopic nature .
    • Mount the pump in-tank, submerged in fuel, to prevent cavitation and ensure consistent cooling .
    • Use a high-quality fuel sock (strainer) on the pump inlet to prevent large particles from entering the pump .

Comparing Popular 255 LPH E85 Fuel Pumps

Several manufacturers offer reliable 255 LPH pumps that are E85-compatible. Here are the most common options:

  • Walbro GSS341 / F90000267: The industry standard. The Walbro 255 LPH high-pressure pump is widely used and trusted. It features a dual-channel turbine design for improved efficiency and is rated for 500-550 hp on gasoline and 400-450 hp on E85 . The pump is available in both standard and offset inlet configurations for easier installation .
  • Deatschwerks DW200: A direct competitor to the Walbro GSS341, the DW200 offers a 3-year warranty for E85 use, which is best in class . It flows 255 LPH at 3 bar (43.5 PSI) and is designed for silent operation . It is compatible with many OEM hanger assemblies and includes a universal installation kit .
  • AEM 50-1200 / 50-1215: AEM’s 320 LPH pump (often listed as 255 LPH equivalent) is designed for high-output EFI vehicles. It is tested to flow 320 LPH at 43 PSI and is compatible with E100, M100, and gasoline . The compact 39mm diameter fits most applications, and the offset inlet design eases installation .
  • Hyperfuel 255 LPH (FiTech): Designed specifically for E85, this pump supports up to 650 hp for EFI and 750 hp for carbureted applications. It features a center inlet and is whisper-quiet . It is a direct replacement for many common pump sizes.

Why You Should Consider the KEMSO Brand for Your Fuel Pump

When building a high-horsepower E85 system, reliability is everything. KEMSO Racing offers a premium line of high-performance, OEM replacement fuel pumps that are engineered for demanding applications.

Why choose KEMSO:

  • High-Performance Design: KEMSO fuel pumps are built to handle the increased flow and pressure demands of E85, ensuring your engine gets the fuel it needs under all conditions.
  • OEM Replacement: Designed as direct replacements for many factory pumps, KEMSO pumps simplify installation and reduce the need for custom modifications.
  • Lifetime Warranty: Every KEMSO fuel pump comes with a lifetime warranty, giving you peace of mind that your investment is protected.

Visit KEMSO Racing today to explore their full line of fuel pumps and supporting components for your E85 build: https://www.kemsoracing.com/

Putting It All Together: Real-World Horsepower Expectations

To summarize, here is what a 255 LPH E85 pump can realistically support:

  • Naturally Aspirated E85: Up to 500-600 hp, depending on engine efficiency and fuel system design.
  • Carbureted E85: Up to 750 hp, due to lower operating pressures .
  • Forced Induction E85: Typically 400-450 hp, because higher fuel pressure reduces flow rate .

For anything beyond these numbers, you will need to either:

  • Use dual 255 LPH pumps in parallel.
  • Upgrade to a single high-flow pump (450 LPH or higher) like the Walbro 450 LPH or 525 LPH .
  • Consider a brushless pump for improved efficiency and longevity at high pressures .

Remember: A fuel pump is only as good as the system it is installed in. Always upgrade your wiring, fuel lines, and pressure regulator to match the pump’s capabilities. And for the most demanding builds, trust a brand like KEMSO that offers lifetime warranty and proven performance.

For more information on high-performance fuel pumps and to find the perfect solution for your build, visit KEMSO Racing at https://www.kemsoracing.com/.


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