End of Injection Timing Open Discussion

[kevinodb1]

Hi Folks

Just to put some perspective of how long it may take for the Fuel to get from the end of the injector to the valve face, here are some calculations:

It is about 2.6 Millisecs at 2000 RPM and 0.8 Millisecs at 6500 RPM, it varies depending on revs, the airflows are from STD EA files that come with the software, I have averaged them.

This time needs to be taken into account in the overall timing for EOIT.

Who knows what speed the Injector is actually spraying at? But we can only assume its mixes with the air and assumes that velocity and that will have to do.

I now finished some other calculations that show the EOIT really is only relevant at low revs because the rest of the time it will never be right anyway, as per what the Lucas Racing reference I posted earlier says.

Still useful for the Low rev scenarios though.

I have updated the original table I had in this post to show transit time of the fuel from the Injector tip to Valve face in Milliseconds.

I have added a second table that shows that for the STD LT1 cam the Intake duration where flow is meaningful(@.050 onwards) is exceeded by the actual Pulsewidth from 2000 RPM on even for small throttle openings.

Cheers
Kevin