Flex Fuel Tuning Guide
07-05-2019, 01:05 PM
#1
Flex Fuel Tuning Guide I have been researching for ideas on tuning flex fuel for a few weeks and I haven’t come up with much other than getting the sensor working (major thanks to roughneck427!)
My car (05 V with P59 PCM) recognizes alcohol percentage and I have copied over the flex fuel spark tables as well as the stoichiometric data for % of alcohol from the L59 motor. Didn’t see anything else that was different for FF in the tune. PCM recognizes alc % and adjusts stoich.
Did a log the other night with 60.5% alcohol content and commanded AFR was about 11.2 at idle. Spark table was set anywhere from 2.9-4* timing in WOT areas of the FF spark table but when I went WOT it was adding more like 7* timing. I am street tuning and I’m a 22* flat across the table on 93 octane but fueling is pretty well dialed in. Still on stock heads, manifolds and cats
Where is the extra timing coming from? Does anyone have a guide on actually tuning FF? I also realize I will not benefit from E till I have a few more mods but I am trying to learn on my own vehicle before I deal with my buddies’ cars.
Derek
My car (05 V with P59 PCM) recognizes alcohol percentage and I have copied over the flex fuel spark tables as well as the stoichiometric data for % of alcohol from the L59 motor. Didn’t see anything else that was different for FF in the tune. PCM recognizes alc % and adjusts stoich.
Did a log the other night with 60.5% alcohol content and commanded AFR was about 11.2 at idle. Spark table was set anywhere from 2.9-4* timing in WOT areas of the FF spark table but when I went WOT it was adding more like 7* timing. I am street tuning and I’m a 22* flat across the table on 93 octane but fueling is pretty well dialed in. Still on stock heads, manifolds and cats
Where is the extra timing coming from? Does anyone have a guide on actually tuning FF? I also realize I will not benefit from E till I have a few more mods but I am trying to learn on my own vehicle before I deal with my buddies’ cars.
Derek
