4g63 Fuel System Upgrades for 600+ Hp: Walbro Pumps and Injector Sizing

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4G63 Fuel System Upgrades for 600+ Hp: Walbro Pumps and Injector Sizing

The 4G63 engine has a storied history in the world of performance tuning, particularly among Mitsubishi enthusiasts. To achieve over 600 horsepower, significant upgrades to the fuel system are essential. This article will explore the best options for fuel pumps and injector sizing to support a high-powered 4G63 build.

Understanding Fuel Requirements

Before diving into specific components, it’s crucial to understand the fuel requirements of a 600+ hp engine. At this power level, the engine demands a reliable and efficient fuel delivery system to maintain optimal performance.

  • Fuel flow rate must meet or exceed engine demands.
  • Fuel pressure must be stable under high-load conditions.
  • Compatibility with high-octane fuels is necessary.

Walbro Fuel Pumps

Walbro pumps are widely regarded as some of the best options for high-performance fuel systems. They offer reliability and high flow rates, making them ideal for a 4G63 engine pushing 600+ hp.

  • Walbro 255 LPH (GSS342) – This pump is a popular choice for many tuners. It can support up to 600 hp with the right injector sizing.
  • Walbro 450 LPH (GSS307) – For those looking for even more capacity, the 450 model is capable of supporting over 800 hp, ensuring ample fuel delivery.

Injector Sizing

Choosing the right fuel injectors is just as critical as selecting the pump. The injectors must be able to deliver enough fuel to meet the engine’s demands while maintaining proper spray patterns for optimal combustion.

Calculating Injector Size

To calculate the required injector size for a 600 hp 4G63, you can use the following formula:

  • Fuel Flow Rate (in lbs/hr) = (Horsepower x BSFC) / Fuel Injector Duty Cycle
  • Typical Brake Specific Fuel Consumption (BSFC) for turbo engines is around 0.6 to 0.8.
  • A safe injector duty cycle is 80% or lower.

For example, if we assume a BSFC of 0.75 and an 80% duty cycle, the calculation for 600 hp would look like this:

  • Fuel Flow Rate = (600 hp x 0.75) / 0.8 = 562.5 lbs/hr
  • 1000cc Injectors – These injectors are a common choice for 600+ hp setups, providing ample flow without sacrificing reliability.
  • 1300cc Injectors – For those who may push beyond 600 hp in the future, 1300cc injectors offer extra capacity and headroom.

Fuel System Considerations

When upgrading the fuel system for a 4G63 engine, several additional components should be considered to ensure a comprehensive and effective setup.

  • Fuel Pressure Regulator: A high-performance adjustable fuel pressure regulator allows for precise tuning of fuel pressure.
  • Fuel Lines: Upgraded fuel lines capable of handling higher pressures are essential to prevent fuel starvation.
  • Fuel Filters: High-flow fuel filters help maintain fuel quality and protect injectors from debris.

Conclusion

Upgrading the fuel system of a 4G63 engine to support 600+ hp requires careful selection of pumps and injectors. Walbro pumps offer reliable performance, while proper injector sizing ensures that the engine receives the fuel it needs for optimal performance. By considering all aspects of the fuel system, you can achieve the horsepower goals while maintaining engine reliability.