Obligitory Disclaimer: Do this at your own risk!
Converting to e85
Trying e85 on the stock fuel system won't get you far, as it requires ~27% more fuel than a gasoline tune. So, you'll need to start by getting upgraded injectors and a fuel pump. For a stock frame turbo a minimum of 850cc injectors and 255 lph fuel pump are recommended. Aftermarket turbo kits or highly modified stock turbo cars would be wise to get 1000cc injectors at a minimum, as well as a double pumper (dual fuel pump) kit from Buschur racing or someone else.
To get your tune roughly close, please see Jack_of_Trades post here: http://forums.evolutionm.net/showthread.php?p=5580387#post5580387
You will also want to increase the amount of fuel and timing in your very low load cells, as well as increase your startup IPW http://forums.evolutionm.net/showthread.php?t=347668 (calculation here http://forums.evolutionm.net/showpost.php?p=6279359&postcount=123 )
There is also quite a bit of interesting information in the MegaSquirt flex fuel manual here: http://www.megamanual.com/flexfuel.htm
Generally, when tuning for e85 one positive is the ability for more boost, but the real power generally comes from the ability to run greatly increased timing.
Generally e85 likes a gas AFR range tune at ~12 AFR, but be careful as some stations (especially in the north / midwest) will change to e70 blends in winter, even though their signs still say e85. A GM Flex fuel sensor with a display from zeitronix can tell you the exact ethanol content of your fuel so you can keep a safe tune.