Injector Size for Honda/Acura I4

Picking the correct injector size for your Honda or Acura engine is critical when playing with more power. The correct injector size is determined by the horsepower the engine can potentially generate. There is also minor variation based on whether the engine a naturally aspirated or forced induction setup.

Below there are two charts. Each chart has the following things in common:

• The injector sizes listed here are recommended minimums. Always round up: 432cc => 450cc, 216cc => 240cc.
• Engine with 4 injectors.
• Maximum duty cycle of 85% for the injectors.
• Stock fuel pressure.
• Uses the formulas found here.

... most EL, Civic, RSX, Integra, Prelude, and Accord injectors are 240-310cc. All EL, Civic and Integra (including TypeR's and JDM models) are 240cc saturated injectors. When choosing aftermarket injectors, pick ones that are larger than 240cc, and that are saturated (high-impedance), NOT peak-and-hold (low-impedance) ones.

Have fun fueling the fire! If you find any problems with the info listed here, feel free to contact me.