On 91 I was seeing 16*, on the 3.8 paxton pulley...should be 9-10psi. On my initial base E50 tune, I was seeing 19*, adding 6 all the way up. I'll report back when I add more and see how much I get.
I'm sure my timing will go up with better e85. I'm sitting at 71% e85 right now. Just finished the tune last week with Lund. Just waiting for the track to open to tune the transmission shift points.