1 gallon of race 114 mixed with 5 gallons of pump 93 would give 96.5 octane based on straight ratios. It doesn't quite work that way but that gives you an idea.

If the race fuel is leaded, it will likely bring up the octane more than the straight ratio calculation. 97?, 98? it depends on the particular make-up of the two fuels. You may have to experiment to find the right mix for your combo.