I'm sure what you experienced was more to do with the turbo boost than valves. Valve timing makes a difference in power and economy, but so does 10lbs of turbo boost. If you search my posts under alcohol fuel, you may see where I have stated several times the loss in economy of ethanol engines could be more than made up in compression ratio's and turbo boost. Converting to ethanol fuel should require a 30lbs turbo boost and 11:1 pistons at a minimum. It will run without it, but you lose efficiency. Ethanol won't ping except under the most dire environment. Dragsters can burn a piston, but they also produce 2000 hp. Flex fuel is just a stop gap measure until we get serious about ethanol. I could take the same 2 liter 4 banger an get 400hp easy to pull a full size truck. When you don't need 400hp, you should get 4-6cyl economy.
If I was guaranteed a steady supply of E85, I would convert in a heartbeat. But once you convert, you can't burn gas, unless you can find 110-120 octane.
I'm sure what you experienced was more to do with the turbo boost than valves. Valve timing makes a difference in power and economy, but so does 10lbs of turbo boost. I thought the same thing but the wastegate had been untouched from the factory. The increase in power was pretty significant, coupled with the fact that the Borg-Warner auto trans wasn't set to handle that increase (as well as the torque improvement) is what led to me spinning off of I-610. It was a pretty weird feeling losing complete control of such a heavy car like that.