Hondata

This may be a bit of a non kmanager specific questions and more of a general EFI question in some regards. What are the values in the fuel table? I've heard of these called 'fuel units'. In something like a split second controller, you have duty ms for secondary injectors for instance. Are the values time or a volume thing?

Also, how are these values related to how much fuel is actually delivered per put. If you have the throttle plate wide open, it's a different world than say 40% open... but the map could still be in the same area.. over 80kpa -- but 40% throttle is quite a bit less air. I guess I'm curious as to how it would not be running way rich under light acceleration that made it to columns 8+ if throttle plate isn't wide open. Any insight into how this is actually working would be great.

Wayne

The values are 'ms' which are milliseconds I believe. If this is true, to figure out the mass of fuel injected for each pulse, you'd have to know some information and make some assumptions. You would need Mdot or mass flow rate, density, area of injector opening, and exit velocity of the fuel, which is related to fuel pressure. Then Mdot = density*velocity*area, so actual mass would be M = Mdot * pulse time.


For your second question, The relationship between MAP and TPS is not necessarily linear. For instance, let just make the assumption that TPS goes from 0 to 100% and MAP goes from 0 to 100 kPa (which is close anyway). Now, in one of my datalogs I just pulled up here, 11% throttle yielded a 55 kPa MAP reading. Later in that log, 100% throttle gave a 98 KPa reading. The relationship is non-linear by far, and the shape of our fuel tables reflect that.

Just to confirm what I thought, I took at datalog on the highway slowly increasing TPS from 0% until I hit WOT, then graphed the results. They did what I thought they'd do.




I believe this has a lot to do with how the valve in a TB acts as well as intake system's geometry, etc....

I think you answered a question I didn't ask

In fact -- I'm not sure how to better word my question -- doh.