I don’t want to increase compression, however my measured squish of 1.14mm is not optimal for racing purposes.

Any input on ideal combustion volumes for the NSR? Running 0.8mm squish on the NX5 with a volume to suit avgas but need to setup the MC21 for unleaded.

I have VHM heads so I can specify 0.8 for the squish but what is the ideal head volume for unleaded. HRC setup manual is -0.22cc on standard using R barrels and SP heads but what is the standard head volume ?

NB: I am not interested how lapping a standard head to tighten squish looses power by increasing compression as a side effect. Only interested in the ideal volume for unleaded. Not interested in avgas specs as this bike will run pump 97.

Tia