gruntguru wrote: ....... In general though, I would think that an F1 engine with highly developed port flow, similar manifold pressure in intake and exhaust, wave tuned exhaust manifold etc, would use valve sizes similar to NA.
BMW won turbo F1 with a nominally stock-block 4 slightly destroked from the N/A F2 using the 1600 cc block
after N/A F2 went 2000 cc free-design Renault made their sportscar race V6 into a turbocharged outright contender for Le Mans
this was destroked for 1500 cc F1 and so had a very high bore:stroke ratio
Honda's 2000 cc F2 dominant V6 had such already, and had extreme b:s ratio when destroked to be their early turbo F1
the point being that the F1 turbo V6s started out with rather huge valve areas (due to their b:s ratios)
also there was a lot of low-hanging development fruit to be gathered before worrying about optimising valve area ratio
as fuels evolved and boost limits came engines were redesigned to much lower b:s ratios
Honda went from 90 mm bore to 82 mm bore, and eventually to 79 mm bore
forcing much reduced valve areas
so only now had inlet:exhaust area ratio become important ?
rules and fuels changed almost overnight then, are we sure that Honda had for 1988 optimised their ratio of inlet:exhaust area ?
or that the drawings in the SAE paper show an optimised arrangement (not an earlier or intentionally misleading one) ?
iirc the Gilles Simon article in RCE 2+ years ago predicted a reduced valve area to allow the best CR and combustion chamber
this might determine the current inlet:exhaust area ratio (the inlet valve being the big factor in this case)