Hey TD can you look again at the Corsair..

[horseback]

Acceleration Chart #5
P-51C @2700rpm (prop pitch 80%) & 3000rpm (prop pitch 100%), La-5FN, LaGG-3 (66), Seafire LF Mk III, & P-38J

Start 270 to 350kph: LaGG-3, 21 seconds; La-5FN, 20 seconds; P-38J, 16 seconds; Seafire LF III, 16 seconds; P-51C @ 2700rpm, 14 seconds; P-51C @ 3000rpm, 14 seconds.

To 370kph: LaGG-3, 28 seconds; La-5FN, 25 seconds; P-38J, 22 seconds; Seafire LF III, 22 seconds; P-51C @ 2700rpm, 19 seconds; P-51C @ 3000rpm, 18 seconds.

To 380kph: LaGG-3, 32 seconds; La-5FN, 28 seconds; P-38J, 25 seconds; Seafire LF III, 26 seconds; P-51C @ 2700rpm, 22 seconds; P-51C @ 3000rpm, 21 seconds.

To 390kph: LaGG-3, 36 seconds; La-5FN, 33 seconds; P-38J, 28 seconds; Seafire LF III, 26 seconds; P-51C @ 2700rpm, 26 seconds; P-51C @ 3000rpm, 24 seconds.

To 400kph: LaGG-3, 41 seconds; La-5FN, 38 seconds; P-38J, 32 seconds; Seafire LF III, 34 seconds; P-51C @ 2700rpm, 30 seconds; P-51C @ 3000rpm, 28 seconds.

To 410kph: LaGG-3, 46 seconds; La-5FN, 38 seconds; P-38J, 37 seconds; Seafire LF III, 41 seconds; P-51C @ 2700rpm, 34 seconds; P-51C @ 3000rpm, 31 seconds.

To 420kph: LaGG-3, 53 seconds; La-5FN, 51 seconds; P-38J, 43 seconds; Seafire LF III, 47 seconds; P-51C @ 2700rpm, 38 seconds; P-51C @ 3000rpm, 34 seconds.

To 430kph: LaGG-3, 1 minute 3 seconds; La-5FN, 1 minute flat; P-38J, 48 seconds; Seafire LF III, 57 seconds; P-51C @ 2700rpm, 42 seconds; P-51C @ 3000rpm, 37 seconds.

To 440kph: LaGG-3, 1 minute 10 seconds; La-5FN, 1 minute 13 seconds; P-38J, 54 seconds; Seafire LF III, 1 minute 7 seconds; P-51C @ 2700rpm, 47 seconds; P-51C @ 3000rpm, 41 seconds.

To 450kph: LaGG-3, 1 minute 20 seconds; La-5FN, 1 minute 27 seconds; P-38J, 1 minute 3 seconds; Seafire LF III, 1 minute 29 seconds; P-51C @ 2700rpm, 52 seconds; P-51C @ 3000rpm, 46 seconds.

To 460kph: LaGG-3, 1 minute 37 seconds; La-5FN, 1 minute 57 seconds; P-38J, 1 minute 15 seconds; P-51C @ 2700rpm, 59 seconds; P-51C @ 3000rpm, 52 seconds.

To 470kph: LaGG-3, 2 minutes 2 seconds; P-38J, 1 minute 33 seconds; P-51C @ 2700rpm, 1 minute 5 seconds; P-51C @ 3000rpm, 57 seconds.

To 480kph: P-38J, 1 minute 54 seconds; P-51C @ 2700rpm, 1 minute 12 seconds; P-51C @ 3000rpm, 1 minute 2 seconds.

To 490kph: P-38J, 2 minutes 34 seconds; P-51C @ 2700rpm, 1 minute 20 seconds; P-51C @ 3000rpm, 1 minute 11 seconds.

To 500kph: P-51C @ 2700rpm, 1 minute 31 seconds; P-51C @ 3000rpm, 1 minute 22 seconds.

To 510kph: P-51C @ 2700rpm, 1 minute 42 seconds; P-51C @ 3000rpm, 1 minute 43 seconds.

To 520kph: P-51C @ 2700rpm, 1 minute 53 seconds; P-51C @ 3000rpm, 2 minutes 3 seconds.

To 530kph: P-51C @ 2700rpm, 2 minutes 15 seconds; P-51C @ 3000rpm, 3 minutes 3 seconds.

NOTES:
1. LaGG-3 and La -5FN were both in supercharger stage 2, 100% Mixture, radiators closed; both exhibited a 'twist' from the torque as the engine had full power applied, causing an abrupt nose up and left motion; compensating with stick & rudder until trim could catch up (sort of) usually resulted in overcompensation and loss of altitude on the order of 20-30 meters. LaGG was faster than I would have expected, La-5FN somewhat slower. Positions may be reversed below 2000m.
2. Both Mustangs were tested at 70% fuel (to simulate non overload condition), as the fuselage tank was not supposed to be over 30 US Gal. when entering the combat zone. Every historical source states that the fuselage tank was added for the sake of extended range, and compromised safety when the aircraft was flown with the tank full. 70% fuel simulates a fuselage tank at the 'safe' level.
3. The Mustang accelerated somewhat faster at 3000rpm between 350 and 500 kph, but couldn't reach 530 kph in level flight and it was much more difficult to trim for semi-level flight; it seemed to porpoise (go up and down by 10-15m in very short periods) unpredictably at the higher speeds.
4. The Lightning was the USAAF's acknowledged champion in climb and straight line acceleration; Il-2 '46's version is extremely stable and easy to keep level, but it should NOT be slower to accelerate than the Mustang at any altitude, even one without a fuselage tank installed.
5. P-38J was the only aircraft in this group that did NOT exhibit a 'twist' when the throttles were slammed forward; the Lightning did, however, try to go straight up. It was exceptionally easy to keep trimmed and straight and level, once you learned to anticipate the tendency to (rapidly) climb as speed increased.
6. Seafire LF III is apparently at the high end of its combat envelope at 3050m; after doing the regular test runs, I took it down to 1500m and throttled up from 350kph--every interval was blazing fast from 350 to around 450 IAS, at which point it slowed to more mortal intervals until it reached 490 kph (540 kph true), or 40 kph faster indicated than it did at 3050m (and about 2 kph faster in TAS at 3050m). At either altitude, it is the twitchy-est Spit version tested so far.

cheers

horseback