No there aren't any calculators or rules of thumb. Also water injection won't necessarily increase the octane as it is measured, but it can be octane equivalent. What I mean is you can tune it in a way that is very similar to an octane grade tune - but it won't be exactly the same.
At 12% to 17% water injected to fuel injected ratios, I have seen many tunes that were very similar to a 110 octane tune in terms of fueling, timing and performance.
|