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I have a couple ideas so I'm curious what the other "self" tuners think, and or do.. I really like the driveability of the 30# injectors. The 42's are what I would call decent for the weekend cruiser, but far from ideal for the daily driver. Rolling idle at startup, deceleration surge,very rich on deceleration, super fat at idle, or super lean at wot. With only one injector slope and no MAF meter there is only so much you can do. I'm not convinced or I suppose just havent had the time to make my truck perfect with the 42's. For now I'm running the 30's again. If the fuel pressure were increased to 55 PSI then the 30's would act more like 39's and be enough for 460 flywheel hp. So after doing something like that obviously the part throttle and wot fueling is going to be off. At wot you may be commanding 13.0, but now you will see 11.0 AFR due to the 30% increase in fuel flow from the pressure increase. So how do you compensate for that? Here are my thoughts on how to do it.
First, you could decrease KVEFF value that is multiplied against your VE table by 30%. This would allow the numbers in my VE table to still appear correct, but the multiplier used against that VE table value "KVEFF" would be lowered by 30% resulting in 30% less fuel for that VE table value. In my case my VE table shows about 91% at wot on the top 2 rows of the VE table. KVEFF(Airmass Flow Multiplier) is 1.4. By decreasing this value by 30%to .98, it should allow me to achieve my commanded 13.0 AFR that I have in my base fuel table under wot load conditions. So by entering 11.5 in the top rows of the base fuel table I should still be able to achieve the commanded AFR during wot. How does that sound to those that know what I'm referring to?
Would I need to change my injector slope value from 30 to 39? If I do that will I need to reduce the injector offset vs batt voltage values by 30%? Will the startup fuel pw values need to also be reduced by 30%? Will adjusting KVEFF take care of all of the above at their original stock 30# settings?
Does the ECM use the VE table values when trying to hone in on stoich in closed loop operation? Does it use the injector slope to do this? Does it use both?
First, you could decrease KVEFF value that is multiplied against your VE table by 30%. This would allow the numbers in my VE table to still appear correct, but the multiplier used against that VE table value "KVEFF" would be lowered by 30% resulting in 30% less fuel for that VE table value. In my case my VE table shows about 91% at wot on the top 2 rows of the VE table. KVEFF(Airmass Flow Multiplier) is 1.4. By decreasing this value by 30%to .98, it should allow me to achieve my commanded 13.0 AFR that I have in my base fuel table under wot load conditions. So by entering 11.5 in the top rows of the base fuel table I should still be able to achieve the commanded AFR during wot. How does that sound to those that know what I'm referring to?
Would I need to change my injector slope value from 30 to 39? If I do that will I need to reduce the injector offset vs batt voltage values by 30%? Will the startup fuel pw values need to also be reduced by 30%? Will adjusting KVEFF take care of all of the above at their original stock 30# settings?
Does the ECM use the VE table values when trying to hone in on stoich in closed loop operation? Does it use the injector slope to do this? Does it use both?
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