I think that would be dependent on how much residual pressure there is in the cylinder. Since ethanol has different heat of combustion you'd probably need to actually test it to see. However we can do a quick check of the ratio of gas molecules in ethanol vs gasoline.
Ethanol burning:
C2H5OH + 3 O2 -> 2 CO2 + 3H2O
Gasoline (assuming an isotrope of octane)
2C8H14 + 23 O2 -> 16 CO2 + 14 H2O
I hope I got that right. Anyways, we see for each mole of oxygen we are making 30/23 moles of exhaust gas, with gasoline. With ethanol, we are making 5/3 moles of exhaust gas for each mole of oxygen, which is a little more. Ethanol's standard enthalpy of combustion is 1371 kJ/mol, with 3 moles of oxygen. Octane has standard enthalpy of comubstion of 5074 kJ/mol, using 11.5 mol of oxygen. This means gasoline produces approximately 441kJ/mol oxygen, while ethanol produces 457kJ/mol oxygen. However ethanol's slightly greater amount of combustion heat is probably offset somewhat by the greater heat of vaporization, but we can see that the behavior of the 2 fuels is somewhat similar. Since ethanol is producing a slightly greater amount of exhaust gas (5/3=~1.667, 30/23=~1.305), it probably would spool a turbo a bit faster. However most of the exhaust is still nitrogen, so the advantage isn't as big as the difference between those 2 ratios. But it does seem like burning ethanol does produce slightly more combustion pressure because of this
Speaking of which, methanol looks like one kickass performance fuel, it has HUGE latent heat of vaporization :O 35kJ/mol vs. 38 for ethanol, but you need twice as much to burn the same amount of oxygen. Dayum.