With various alternative fuels it's adviced to change the C/R. Now what are some general rules of the thumb / good ideas for compression when you run these fuels? I'm talking about E85, CNG, LPG primairily but also racegas like C12 and C16. Also turbo and N/A. In stock form the N/A UZ is like C/R 10 or 10.5. Anyone played with this already?