understanding injector setup page

[garz]

For the calibration listed as 310cc injectors the fuel table values have been increased (roughly doubled). For more information you would have to ask each tuner why they did it that way.

thanks hondata - but that's the bit I'm not following
in the kal with the injectors listed as 310cc the fuel table values at WOT are around 2000
whereas in the kal with the injectors listed as 630cc the fuel table values at WOT are around 4000 -

ie double on the 630cc kal vs the 310cc - so the other way around ......?

[Hondata]

The higher the injector size the lower the injector pulse width. So the calibration with the higher fuel table values and higher injector size would be about the same as the other calibration.

[garz]

The higher the injector size the lower the injector pulse width. So the calibration with the higher fuel table values and higher injector size would be about the same as the other calibration.

thanks again - and i am really sorry if i am just not comprehending something obvious - but

if, per your first statement, the higher the injector size the lower the pulse width (for the same fuel flow) - then why does the higher injector size kal have LARGER fuel table numbers - not smaller ones ?

or put another way: To give approx. equivalent flow i would have expected the 310cc injectors to have to open for approx 2x a long as the 630cc injectors ( since they are around half the capacity ) and so i would have expected the fuel table numbers in the 310cc kal to be double those of the 630cc kal
but in fact its the other way around

so, it seems to be reversed if you see what i mean?

is the number in the main fuel tables not proportional to open duration?

[Hondata]

Let's say the 630cc injectors flow double that of the 310cc injectors.

If one calibration has injector=310cc and table=1000 and the other has injector=630cc and table=2000 then the injector pulse width will be the same.

It is a likely that the opposite has happened - the calibration with the injector entered as 310cc has had the fuel table values halved.

[garz]

thanks again for the reply

If one calibration has injector=310cc and table=1000 and the other has injector=630cc and table=2000 then the injector pulse width will be the same.

ah - ok - so it is reversed from what you would expect - the larger injector has a BIGGER number in the fuel tables as well as a bigger flow rate - wow!
at least this explains why the two maps run fine on the car - despite the apparent larger numbers in the bigger injector fuel tables

i guess the ecu must apply some non-visible calculations further down the chain of processes to take that bigger fuel table number and arrive at the same injector pulse - and the fuel table numbers are therefore pretty arbitrary - with the scaling driven by things we cannot see going on inside the ECU

It is a likely that the opposite has happened - the calibration with the injector entered as 310cc has had the fuel table values halved.

not sure i follow that bit - it seems like exactly what you said in your first sentence is all we need to explain what i am seeing - no?

[garz]

just to confirm the above - i did 2 sets of datalogs in the car - one with each kal - both at steady 70mph indicated vehicle speed

as expected the injector pulse widths are within 10% of each other -
confirming the 4000 fuel table value with the 630cc injector delivers the same fuel as the 2000 fuel table value with the 310cc injector

so it seems the ecu/kmanager software applies some non-meaningful scaling to the fuel table axis, via a calculation we cannot see, in order to display something visually useful on screen while you are tuning - but then later converts this back to an appropriate injector duration further down the chain of calculation steps

thanks for helping clear this up - it was confusing me

[6nfanatic]

Hi,

i agree with garz. Its confusing. So just to confirm: I am running a car on the stock 310cc inj with a fuelmap. Now i switch the 310cc with 440cc.
I dial that that in in the "inj size" tab. What do i need to do now to basically get the car started? It seems that the car is now VERY rich, the plugs are black and it wont start.
I had the thinking that entering the 440cc in the inj-size would affect the whole map, somehow "scaling it down"..

Do i also need to calculate ~ -40% to all my fuel tables?