Staged injectors

[ATS_Scott]

Anyone tried this before? I think I need to set-up the injector O/P to custom 44 then I simply set-up the fuel trims for inj. 5-8. to be off until I estimate I'll need them, and adjust the main fuel table to compensate? Should I roll the second set on gradually, or just set them to say 50% and adjust from there? Anyone have a better solution?
Thanks,
Scott

[Pavlo]

Read the help on the ECUCAL software. Inj O/P 44 should work, but you need to set the secondaries to 61.7% in the inj trim tables to turn them off in the areas you don't want them being used. You can phase them in gradually or in fairly quickly, bu t do it in an area you don't sit at for long periods to stop them phasing in and out whilst cruising for instance.

You can reduce the primary trims in the same area if you want, but them be aware that the injector opening times will be different between the 2 sets, and you need to log injector times for each set of injectors to know if you're macing either set out.

[MRMRacing]

Moved this to supportforum, administrator.

[ATS_Scott]

Pavlo, Thanks for the input. I'll give it a try.
I'm mainly concerned with actual implementation, (tuning) with either the injector trims, or main fuel table.

I suppose I'll try rolling in the secondaries quickly, and then just tune with the main fuel table, If I can't get duty cycles down where I need them, I can trim primaries and secondaries equally. I think then my main fuel table will make sense. Seem like a good approach?

[Ian]

Are both the staged and normal injectors the same size or different? I setup staged injectors as follows;

Calculate the Base Fuel Multiplier for both injectors on. If the injectors are the same size then multiply the BFM by (4/3) and input the new value.
In the injector trim tables set the normal cylinder trims to 150 and the staged cylinder trims to 61.7 (Off).
Setup Load lines in the trim tables as suitable for your staging. The prestaging Load line will show 150 for normal injectors and 61.7 for the secondary injectors. The line where the secondary injectors start to switch on will show 150 for the normal injectors and 62.1 for the secondary injectors. The load line for all injectors on will show 75 for both normal and staged injectors. The 75% factor multiplied by the (4/3) factor in the recalculated BFM means the Base Fuel delivery table will not appear any different to a normal calibration.

The cylinder trims allow a range of 2.6 so provided that the injector flows are within a 1.6 range additional trims are not required. If the range isn't enough then I prefer to use one of the Aux Trim tables to correct the difference rather than the Base Fuel Delivery table.

[ATS_Scott]

Ian, Thanks for the detailed reply. That was exactly what I was looking for, and makes good sense. I'm actually not sure of injector size yet. I need to get that nailed down soon. Thanks again!