Im trying to get my idle air fuel ratio leaned out on a turbo 5.3 running E85. I have managed to get a decent idle speed and it starts and runs but is really rich at Idle. This is a no O2 sensor, SD only, open loop tune. I have widebands for both sides of engine. I have tried ID2000 and FIC2150 data but cant seem to get the AFR above .7 lambda at idle. I have the upper RPM tuned to .79 Lambda (1.225 in BE). I have throttle position % set to a higher then normal setting for PE (1.13) so it is not enriching at idle. I have tried going from normal injector pulsewidth and offset values down to .1ms. The car runs great for what it is, a stock LM7 with a cam change and 12 PSI boost from a China GT45 turbo, but the richness at idle is bothering me. using 240lb/hr injector flow at 58psi base.
LM7 5.3L stock bottom end.
Stock 862 Heads.
LS9 head gaskets
BTR Turbo cam and springs.
Single Walbro 450 LPH, 58PSI base.
E85 that tests right now at E70. (10.7 Stoich setting)
2900 lbs with driver ran a 9.69 @143MPH
Thanks in advance, any help is appreciated.