Originally Posted by
cobaltssoverbooster
yea they shut the alch comp system down. under virtual mode if the engine sees no vacuum changes, no premature detonation events and can correct for the fuel ratio by trimming it will skew the trims by adding a virtual alch comp value. Its a pain in the ass when it tries to wander around figuring out fuel but if you fix the tables to treat alcohol the same as pump gas then it should not wander on you. Downside you cant run e85 as a blended tuning option, you will have to have designated tune files.
someone tried to upgrade the system to have an actual blend sensor inputting data but they had a little trouble getting the computer to switch correctly between the tables and ended up going back to the stock virtual programming. if you add one in and get it to work that would make you the first i know of finishing the conversion.