Flow honing is a process that opens up an injector nozzle to gain more fuel flow. A flow hone nozzle usually flows 15-20% more fuel than a comparable lpm edm'd nozzle, meaning a 50 lpm flow honed nozzle will flow 15-20% more than a 50 lpm edm'd nozzle.Either flow hone your stock ones or can add this option for a set of new injectors or nozzles. Generally one can open up a set of injectors about 10-15% on what they flow in LPM (liters per minute).