Ebay GT45 + 5.9 Magnum + E85 blow thru
Also,,Speed density system CANNOT account for changing exhaust restrictions that alter VE. So a shift in A/F Lean is common when uncorking a closed system that maybe limiting output, at least in open loop
Also exhaust pressure alters a wide band's accuracy, assuming its even accurate to begin with and not too close to the exit or there's any upstream leaks.
Make sure this setting doesnt happen to be 50%