Ive been looking at the various signatures of you guys, and at all of the mods that involve fuel pressure regulators, and injectors and have a question that I cant seem to find the answer to.

Im guessing that 40#, 60# etc fuel injectors refer to how many pounds of fuel the injectors will deliver per hour at wide open throttle, is this correct?

It makes sense that more fuel equals more power, but how does fuel pressure figure into the equation? I have always been told that liquid gas will not burn, that only the fumes will burn, which is why the fuel injectors atomize the gas, so my question involves a higher fuel pressure to create a finer mist as it enters the combustion chamber, will this if nothing else result in better fuel mileage, and possibly more horsepower as you should get a better burn?

And finally, if this theory is correct, is it accomplished with nothing more then an inline fuel pressure regulator or is it something else that would also need to be done? While Im on the ssbject of gas and air mixtures, my friend has a little rice burner Acura Integra, it has been heavily modded, and is pretty snappy. He has a guage that monitors for lack of a better term the richness of the fuel. It has LEDs on it, and bounces around in red/yellow/green bands while normal driving conditions, but when he hits it it goes all green. He said it ensures there is enough O2 to fuel to ensure proper combustion, is this something that any of you guys worry about, or is this something that is more important on small heavily modified engines?

As always, thanks for any input and responses.

 

Fuel injectors are rated at what is the maximum volume of fuel they can flow. IE: 60# injectors will flow 60# an hour at 43.5 psi fuel pressure. This is from memory. They will flow something like 70 something # hour at GM fuel pressure of 58 psi.

At WOT they are timed/pulsed to flow the amount of fuel you need to maintain your commanded AFR which should be somewhere at 80% or less of the maximum they are capable of flowing.

Your buddy sounds like he has a narrowband AFR gauge, which basically tells him that his AFR is somewhere above or below stoich AFR of 14.7:1. To accurately determing AFR you need a Wideband 02 sensor and gauge... Yes it is very important to monitor and tune based upon your AFR.

 

Injectors are rated for a particular flow at a particular pressure. So more pressure equates to more flow (to a point) fuel injectors are made to cycle and do not operate consistently at static flow (full open) which is why we like to keep them operating below the 80% range. For an afr sensor a narrowband is just a flashy POS that is useless for WOT fueling since they are only capable of tell you lean or rich from 14.7:1 and optimal WOT fuel is in the rich range. You need a wideband O2 to really be useful in reading how rich or lean the fueling is.

 

Thanks for the help seems to make sense to me.