03-14-2019, 05:32 PM
Im working on a 2250 ISB thats been deleted by a reputable tuner but this truck is experiencing heavier than usual fuel consumption.
I noticed a couple of things - first thing - The turbo is closing to 94% at idle (stock setting) and since its deleted - i dont see why that needs to happen. I watched final fueling and adjusted VGA position while the truck was at idle and noticed by opening the turbo from 94% to 50%, it dropped from 11.5 mg/stroke to 9.5 mg/ stroke. with the amount of idling this truck does - theres no reason to make boost at idle and use the extra fuel so I went searching for the table that controls it but had no luck finding it.
the tables that control the upper and lower VGT limits had no effect on this so there must be something else - hopefully someone can chime in on what needs to be adjusted to stop the turbo from making boost at idle.
Second thing - I know engineers develop these engines to have the best mix of power / economy within the target guidelines of NOx production but since this engine is deleted and were not worried about NOx production, I was considering making small adjustments to the main SOI increment to slightly advance the injection timing and see what kind of mileage gains / losses come from it.
My question there is; has anyone jumped into this?
I noticed a couple of things - first thing - The turbo is closing to 94% at idle (stock setting) and since its deleted - i dont see why that needs to happen. I watched final fueling and adjusted VGA position while the truck was at idle and noticed by opening the turbo from 94% to 50%, it dropped from 11.5 mg/stroke to 9.5 mg/ stroke. with the amount of idling this truck does - theres no reason to make boost at idle and use the extra fuel so I went searching for the table that controls it but had no luck finding it.
the tables that control the upper and lower VGT limits had no effect on this so there must be something else - hopefully someone can chime in on what needs to be adjusted to stop the turbo from making boost at idle.
Second thing - I know engineers develop these engines to have the best mix of power / economy within the target guidelines of NOx production but since this engine is deleted and were not worried about NOx production, I was considering making small adjustments to the main SOI increment to slightly advance the injection timing and see what kind of mileage gains / losses come from it.
My question there is; has anyone jumped into this?
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