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that's what i'm really tryin to figure out. I know there is a point the extra compression is not worth the little gain. the engine has to work harder driving the next piston up on compression. don't want to use exspensive race fuel neither. like to run it on 110. looks like 16:1 is the platue as far as diminishing returns. thanks

I think what you are really asking is when does the benefit of a higher CR exceed the $ cost associated with the initial build and maintenance. You can't just look at a curve that only represents power gain wit a higher CR. You have to look at the intersecting point between the power gain curve and the cost curve ( includes build costs and some amount of breakage / repair costs ). So how much $ do you have to spend on the $ curve? Initial build $ should be easy enough to get. Breakage side will be a guess - but there will be some and it will go up with the CR. If you want to use fuel ( 110 )as your limiting factor: When the max wedge first came out in 63, it was available with 13.5:1 Cr. In 64 they dropped it to 12.5:1. Same HP rating. Just about everyone ran on Sunoco 110 gas. Don't forget the most important rule in drag racing - getting from point A to point B - consistently.

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