[CaryTheLabelGuy]

Furthermore, 4gals of E85 (testing a true 85%) mixed with 91 oct (E10) is about 94 octane (E29) (R+M/2) and that's if you have access to decent 91.

Contrast that to E85/93 octane mixes, 4gals of 93 octane (E10) mixed with true E85 is also E29, but overall octane is raised to right at 96 octane (R+M/2).

It's not until you get into the E30+ range before you really start to significantly increase the detonation threshold, especially mixed with a quality 93 octane.

By E60 or so (especially with a quality 93 blend), you have most of the benefits of running a full-tank of E85......key word here being 'most'. "The more ethanol the better", will always be true. Obviously your car is incapable of running much more ethanol content than E32 (unless you have a ZCP, then you can get to about E40 or so), but it's better than 91 by itself for sure. I wouldn't venture past Map 2 or maybe a map 6 targeting no more than 21 psi or so.

Like stated above, you need increase your FOL to at least 70 or even try 75.