Honda Hunter

What is the exact stock LT1 injector flow rate? Example 24.xx

Injuneer

24.896 #/HR (3.14 grams/sec)

That's what programmed into a stock PCM.

Honda Hunter

Thanks. Also what's the stock display injector flow rate?

sssalah

What do you mean by display?

Honda Hunter

Using Tunercat, in the ECM constant table it's the third option down. Right now mine is set at 3.81 GL/HR

rskrause

Fred's post was actually quite droll. There is no "exact" flow rate - it depends on what pressure the flow is measured at. A lot of the values in the PCM are somewhat arbitrary, and I am sure the injector flow rate of "24.896lb/h" is too. No one would bother to try to measure to the thousanth of a pound and there would a lot more variation than that between injectors so as to make a meaurement that precise meaningless anyway. That said, they do flow ~24lb/h at 43.5lbs of fuel pressure.

Rich

Injuneer

Actually, I suspect they rated it to 2 decimal places in grams/sec, and when they converted to pounds/hour, they just left it at 5 significant figures, rather than truncate it.

sssalah

Haven't worked with tunercat, but I guess you could change the units as in lt1-edit. I don't know why in tunercat it's expressed in volume rather than mass. If you consider the SG of gasoline at 0.78 then the mass flow would be 3.12 gm/sec.

rskrause

Well, to split a hair or two, volume/time IS a more logical way to express injector flow rate than mass/time. For a given delta P, the main determinant of injector flow would be simply the opening time. For liquids with similar viscosity, a similar volume would flow in the same period of time. The mass could vary by quite a bit. If you look at VP's web site http://www.vpracingfuels.com/vp_01_f...B7C8224762A4A2 you can see that there is a range of specific gravities that is large: from .676 to .800. This is a range of nearly 20%. This would create a large differnce in mass/h and likely an insigfnificant difference in volume/h.

Rich