Spitfire makes only 300 mph?

[fruitbat]

Originally Posted by ICDP

I took a Spitfire MkII on a seal level speed test, quick mission over the channel. With a well trimmed and slightly open radiator I was able to get about 311mph IAS. This speed would indicate the Spitfire MkII is indeed using 100 octane fuel.

Make sure to adjust your prop for best speed, this isn't IL2 where you leave it on 3000 RPM at all times. I found the best to be around 2600 - 2800 RPM.

Inidentally, the boost guage only goes up to 8lb but that doesn't mean that is the bost we get. Spitfires in BoB still had the old boost guage and when pulling full boost the needle was off the guage with 100 octane fuel.

As I said, the speed seems to match a MkIIa with 100 octane fuel.

i think you may be right, figures i have (P 7280 test Boscombe Down sept 1940) show spit MkII top speed at 290mph at sea level on 9lbs boost.

@25 mph is about right for the diff between 87 octane and 100 octane fuel at sea level according to my sources, so pretty close.

Spit MkII according to this test, makes 354mph at 17554ft.