Injectors

When choosing injectors for tuning, motorsport or performance, the size must match the engine’s expected power level. However, it is important not only to choose injectors based on the exact power target, but also to add a little extra capacity so the injectors do not run all the way up to maximum duty cycle under full load for extended periods of time.

If the injectors are pushed to run almost fully open, it can reduce the safety margin of the fuel system and make the setup less optimal. That is why injectors are often chosen with a little extra capacity, so there is some headroom in the system when the engine is under heavy load. As a practical example, a project with a 4-cylinder engine targeting around 300 hp will typically require 4 injectors of approximately 441 cc. This provides a little extra reserve, so the fuel system is not operating right at the limit under high load.

Qualitec injectors fit almost all cars. They come with 14 mm O-rings, and the length is typically always the same across all cars. The length from centre to centre of the O-ring is approximately 64 mm. You can also see our guide to injector sizes.