my spitfire starts shaking and i dunno why

[Nightdare]

I'll be honest, I never experienced boost ingame as described by the many pilots in historical accounts, and I mean the empirical effects, not the "seat of the pants" feeling
Yeah I see my revs jump maybe 500, but any actual reaction in some kind of impressive speed boost?

[ATAG_Snapper]

I'll be honest, I never experienced boost ingame as described by the many pilots in historical accounts, and I mean the empirical effects, not the "seat of the pants" feeling
Yeah I see my revs jump maybe 500, but any actual reaction in some kind of impressive speed boost?

You raise an interesting question. To my wife’s chagrin, I abandoned her dinner preparations to head down to my PC. I then made a series of the most boring video clips known to mankind to verify the effects of going to boost cut out override (ie 6.5 lbs boost to 12 lbs boost) at sea level. I won’t subject you to them (they ARE boring! LOL), but here’s the gist of ‘em:

Allied fighters tested (all fuelled with 100 octane): Hurricane 1 DH5-20, Hurricane 1 Rotol, Spitfire 1, Spitfire 1a, Spitfire 2a.

I used the first Single Mission, spawning in air over the channel. I promptly descended to near-sea level (100 feet). I then determined the maximum speed for each aircraft at 6.5 lbs boost in level flight. I allowed a couple of minutes for each plane to settle at its max speed.

In every case, I set the rpms to 3,000 using the prop pitch control (the Hurri 5-20 I kept the 2-speed prop in Coarse setting which ultimately yielded 2500 rpms at 6.5 boost).

I gradually increased engine boost to 6.5 lbs, and closed the radiator to 35% (= optimum setting for minimal drag). I carefully adjusted rudder trim to show 0 yaw. This is where, after 2 minutes of steady running, I recorded the Indicated Air Speed. Hint: use CTL F1 “Wonder Woman view” which has the instruments displayed around the periphery of your monitor screen. These instruments give much more precise and accurate readouts than the usual in-cockpit instruments.

Next, hit the boost cut out override switch (the red throttle gate in the Spits, pull the tit in the Hurries). Nudge your throttle to go from 100% to 110%. The engine boost will immediately increase to 12 lbs, and your IAS will quickly jump up 10-15 mph. If flying in a real aircraft, THIS is what you would feel in the seat of your pants. Speed in all of the aircraft will soon increase a total of about 20 mph over that achieved at 6.5 lbs of engine boost. In a chase or flee situation, 20 mph can mean the difference between victory or defeat.

Couple of caveats:

Only use 35% rads when your IAS is 300+ mph on the deck. Less airspeed (or worse yet, in a climb) will cause your Merlin to overheat very quickly.

Wanna know a little secret? Take the Spitfire Mk 1 out for a spin. Be careful - it’s easy to over rev the engine unless you constantly monitor your prop pitch. 3,000 rpms is the absolute maximum. Unless...you’re prepared to cheat fate a little bit. If you’re running flat out on the deck at 12 lbs boost (= 110% throttle) and 3,000 rpms (= 15% prop pitch), radiator is at 35% and you’re trimmed out for 0 yaw and going about 305 mph...



inch your prop pitch forward very slightly to increase revs to 3200 rpms (not 3300, but 3200). Then watch that smug 109 E3B pilot you’re chasing on the deck crap his drawers.