Black 6 Thu 19th Apr update re Spit II

[Talisman]

Originally Posted by 41Sqn_Banks

I'm not sure if the emergency boost was cleared for the Merlin XII at that time, e.g. for the Merlin XX it was cleared in November 1940, see http://www.wwiiaircraftperformance.o...xx-15nov40.jpg.

High Banks,

Just to clarify, are you suggesting that the RAF introduced a new MkII version of the Spitfire in the middle of the battle that did not have emergency operational power for combat and thus was slower in combat than the Spit MkI with operational emergency boost engaged?

The Spit MkII test data states the following vs the Spit MkI (N.3171):

4.0 Level Speeds.

.......The top speed of this aeroplane is the same as that of N.3171 but is reached at 17,600 feet, 1400 feet lower than the Mk.I Spitfire. Consequent upon this and the increase in power of the Merlin XII over the Merlin III below full throttle height the aeroplane is about 6 - 7 miles per hour faster at heights less than 17,000 feet and about 4 - 8 m.p.h. slower at heights above 20,000 feet. It should be noted that though the boost pressure on the Merlin XII is +9 lb. per sq.inch as against +6 1/4 lb. per sq.inch on the Merlin III there is little difference in the engine power at heights of 16,000 feet and above.

So, if the Spit MkI is 6 to 7 mph slower at heights less than 17,000 ft, then to my mind the data indicates that the level speed of the Spit MkI at 1,000 ft was 287 mph ( Spit II, 294 mph at 1,000 ft minus 7 = 287). If the Spit I pilot then engages operational emergency boost, he then gets an extra 25 to 30 mph, giving a speed of 312 mph (287 + 25) at 1,000 feet on 100 Octane fuel.

So, with the Spit MkI at 312 mph on emergency boost at 1,000 feet and the Spit Mk II at 294 mph without emergency boost, it is slower in combat than the Spit MkI unless the Spit MkII has emergency boost available. Or am I missing something? Surely the Spit MkII had emergencey power operational boost available to provide and extra 25 to 30 mph for operational emergency, just like the Spit MkI.

For me, the test data shows how the Spit MkI can be bench-marked against the Spit MkII in terms of performance for the CloD dev team. What do you think?

The fact that the CloD sim provides a Spit MkI that only makes approx 240 mph level speed at 1,000 feet, rather than the historic record of approx 287 mph (312 mph with emergency boost on 100 Octane fuel) is very disappointing from a historical accuracy perspective.

Also, surely the boost dial on the Spit Mk II in the CloD sim should read over 8lbs.

Talisman