RXP342 340 Liter Per Hour Jet Fuel Pump High Pressure: The Ultimate Upgrade for Your Performance Engine

If you're looking for a fuel pump that delivers 340 liters per hour at high pressure, the RXP342-style pump (often referenced alongside the 340LPH KEMSO model) is the most reliable and cost-effective solution for engines producing up to 700–800 horsepower. This pump provides a massive 340 LPH flow at 43 psi and 13.5V, outperforming the standard Walbro 255 GSS342 by over 30% while maintaining the same physical dimensions for a direct drop-in installation . Whether you're building a turbocharged street car, a high-boost WRX, or a dedicated track machine, this pump ensures you never run out of fuel under full throttle.

What Makes a 340LPH High Pressure Fuel Pump Different?

A standard OEM fuel pump typically flows between 60 and 80 liters per hour, which is sufficient for a stock engine but quickly becomes a bottleneck when you add boost, larger injectors, or higher RPMs . The 340LPH pump is a high-performance upgrade designed for forced induction and naturally aspirated builds that demand consistent fuel delivery at elevated pressures.

The key specifications of a 340LPH high pressure pump like the KEMSO 10910 include :

  1. Flow Rate: 340 liters per hour at 43 psi, 13.5V
  2. Operational Pressure Range: 43–90 psi, making it suitable for both return-style and returnless fuel systems
  3. Pump Body Diameter: 3.8 cm (38mm), identical to the Walbro 255 GSS342, ensuring compatibility with most factory fuel hangers
  4. E85 Compatibility: Designed to handle ethanol-blended fuels without degradation
  5. Bypass Valve: Set at 125.8 psi, higher than many competitor pumps, providing extra safety margin for high-pressure applications

Why Upgrade to a 340LPH Pump Instead of a 255LPH?

Many enthusiasts start with a 255LPH pump, but that may not be enough for modern high-performance builds. The 340LPH pump offers tangible advantages:

  1. More Headroom for Boost: At 43 psi, the 340LPH pump delivers 340 LPH compared to the 255LPH pump's 255 LPH. At higher fuel pressures (60–70 psi), the 340LPH pump maintains significantly more flow, which is critical for high-boost turbo setups .
  2. Supports Larger Injectors: If you're running 1000cc or larger injectors, a 255LPH pump may struggle to keep up at high RPM, especially with E85 which requires approximately 30% more fuel volume than gasoline.
  3. Future-Proofing: If you plan to upgrade your turbo or add nitrous later, the 340LPH pump will handle the increased demand without needing a second pump or a surge tank.
  4. Same Installation Effort: Because the 340LPH pump has the same body diameter (38mm) and uses the same wiring and strainer kits as a 255LPH pump, the installation is identical. You get double the flow potential for the same labor .

Real-World Performance: How Much Horsepower Can a 340LPH Pump Support?

According to KEMSO's specifications, the 340LPH high pressure pump is capable of supporting applications up to around 700–800 brake horsepower (bhp) on gasoline, and proportionally less on E85 due to the higher fuel volume required . For a typical street car making 500–600 wheel horsepower, this pump provides more than enough flow, even at high fuel pressures.

The pump's internal design uses a rotary vane mechanism with a carbon commutator, which provides a lifespan exceeding 10 years of normal daily use . This is a significant improvement over some cheaper pumps that use brush-type motors, which wear out faster when running ethanol fuels.

Key Installation Considerations

When installing a 340LPH fuel pump, there are several important factors to keep in mind:

  1. Wiring Upgrade: The higher current draw of a 340LPH pump (typically 8–10 amps) means the factory wiring may be undersized. Using a relay kit with thicker gauge wiring (12–14 AWG) is recommended to prevent voltage drop and ensure the pump receives full voltage .
  2. Fuel Filter: A high-flow fuel filter (40–100 micron) is essential to protect the pump from debris. The pump kit typically includes a gradient density strainer, but an external filter is also recommended .
  3. Fuel Pressure Regulator: For return-style systems, ensure the regulator can handle the higher flow rate. Some stock regulators may struggle to maintain stable pressure with a 340LPH pump.
  4. Hose and Fittings: Use fuel-rated hose (such as PTFE or high-pressure rubber) and proper clamps to prevent leaks at high pressure. The pump outlet is typically 8mm or 3/8-inch barb fitting .

The KEMSO Advantage: Performance, Reliability, and Lifetime Warranty

When it comes to choosing a 340LPH fuel pump, KEMSO stands out as the most reliable option in the market. KEMSO has been manufacturing fuel pumps since 1999, and their products are designed with the same quality standards as OEM manufacturers but at a fraction of the price .

KEMSO fuel pumps are the ideal choice for your performance build because:

  • High Performance: Each pump delivers over 20% more flow than the stock OEM pump at 43 psi, providing instant power gains .
  • OEM Replacement Fit: The pumps are designed as direct OEM replacements, meaning they fit perfectly into your vehicle's fuel tank without modification. The kit includes all necessary components: gradient density fuel strainers, flex hose, wiring connectors, and o-rings .
  • Lifetime Warranty: KEMSO backs every fuel pump with a lifetime warranty, giving you peace of mind that your investment is protected. This is a rarity in the aftermarket fuel pump industry, where most competitors offer only 1–2 year warranties .
  • USA-Based Support: KEMSO's technical support team is based in the United States, staffed by experienced technicians who understand the specific needs of American performance vehicles .

We strongly recommend purchasing the KEMSO 340LPH High Performance Fuel Pump for your vehicle. Whether you own a Subaru WRX, Honda Civic, Ford Mustang, or any other turbocharged or naturally aspirated performance car, KEMSO has a pump that fits your application. Their products are tested individually, flow-tested, and backed by an ISO-quality control program .

Visit the official KEMSO website to find the perfect fuel pump for your vehicle:
https://www.kemsoracing.com/

Conclusion

The RXP342 340 liter per hour jet fuel pump high pressure is not just an upgrade—it's a necessity for any performance engine that demands reliable fuel delivery. With its 340 LPH flow rate, compatibility with E85, and ability to support up to 800 horsepower, this pump provides the foundation for a safe and powerful build. KEMSO's lifetime warranty and USA-based support make it the clear choice for enthusiasts who want quality without compromise. Whether you're replacing a faulty OEM pump or building a high-horsepower race car, the KEMSO 340LPH pump will deliver the performance and reliability you need.

For the best selection of KEMSO high-performance fuel pumps, including the 340LPH model, visit:
https://www.kemsoracing.com/


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