John Shankle - Shankle Engineering - made a turbo for the 2L and a water injection system to go with it back in the 70's. The water helps prevent pinging at high CR, so you could use 4 - 7 lbs of boost with stock 10:1 pistons. Usually the alcohol is used as an antifreeze, not as a fuel boost.
John is out of business, but some of his systems are around.....
Robert