[Kwiatek]

Originally Posted by *Buzzsaw*

Wrong. The Spit II has lower performance than an aircraft at +8.8 boost:



Image courtesy of Mike Williams Spitifire Performance site:

http://www.spitfireperformance.com/spittest.html

If you give more focus on both test - Spitfire MK1 and MKII you will note thath MK II was equimpment with aditional pilot armour ( was more heavy) and MK1 has only armoured windscreen ( without pilot armour). Thats why at higher alts above 18 000 ft where boost preasure for both engines - Merlin III and Merlin XII was similar Spitfire MK1 with lower weight was faster. At lower alts MKII at nominal power ( +9lbs) was faster then MKI ( + 6 1/2 lbs) but at emergency power +12 lbs MK1 could be little bit better ( expecially in climb rate).