Originally Posted by fahr_side
We were discussing why it that cars running given power levels can get away with running smaller turbines and exhaust housings on e85 than those burning gasoline. The effects of high-octane / low-calorific-value fuels on CR, timing and boost are well-understood.
You were talking about this? - The smaller turbos reach their max efficiency sooner and therefore heat up quicker then larger turbos, but because ethanol burns cooler then gas, the air charge remains cooler and more dense which means more total air molecules.