Most of the Spitfire V Merlin 45 data has maximum boost is 9 lb. or 16 lb. What date was the 9 lb. boost increased to 16 lb., or 12 lb.? :?:
My favorite Spitfire site Spitfire Performance Testing
Boost (lb/sq.in.)
(i) Max. for climbing (normal rating)(1 hr. limit) +9
(ii) Max. for...