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The dynamic compression ratio doesn't mean anything when picking a fuel for racing. Once the engine speed gets into a range where the cylinder is getting a full charge of air then you need good gas.

Call any race fuel engineer and ask them or look on their websites. Nobody picks fuel by dynamic compression ratio when racing, all of the charts are static compression ratio.




There's nothing 'dynamic' about the so-called Dynamic Compression ratio. It's just Static compression based on intake valve closing point instead of BDC. A true Dynamic Compression Ratio would include Volumetric Efficiency and the Thermodynamic conditions inside a running engine. Unfortunately, you can't calculate that kind of stuff on a calculator or spread sheet, it's just too complex. However, if you just substitute 100% Volumetric Efficiency and calculate you're right back at the good old (volume@BDC)/(volume@TDC) compression ratio of old. (That's me agreeing with Andy)

It sounds like a good E85 build to me but it seems that the owner has an aversion to Ethanol, at least as a fuel.