Aces High Bulletin Board

General Forums => Aircraft and Vehicles => Topic started by: Wmaker on July 29, 2011, 12:28:01 PM

Title: P-40B's top speed on the deck.
Post by: Wmaker on July 29, 2011, 12:28:01 PM
One thing I've been wondering is the P-40B's rather low top speed on the deck in Aces High. Slightly below 280mph.

Dean's America's Hundred Thousand gives a speed curve for the first production "plain P-40" which comes out at ~320mph on the deck. The first production P-40 was indeed several hundred pounds lighter than P-40B but it's hard to imagine that the induced drag caused by it at low altitude would cause several tens of miles reduction to the top speed at that particular altitude. The "plain P-40" had the same powerplant according to AHT. Indeed 320mph sounds a bit high side but 280mph certainly sounds low.

I'll look up some primary source material for the P-40B and post it to this thread later.
Title: Re: P-40B's top speed on the deck.
Post by: Krusty on July 29, 2011, 12:35:43 PM
Might check some of the things WideWing has posted on it. It looks like they modeled the worst of the lot, the P-40C, instead of the P-40B. Performance wise, that explains the poor top speed.
Title: Re: P-40B's top speed on the deck.
Post by: Widewing on July 29, 2011, 12:43:34 PM
Might check some of the things WideWing has posted on it. It looks like they modeled the worst of the lot, the P-40C, instead of the P-40B. Performance wise, that explains the poor top speed.

Yep, the P-40C had drop tank shackles hanging in the wind, and weighed considerably more. I have no doubt that the AHII P-40B utilizes P-40C/Tomahawk IIB performance data. Weights seem to confirm this, and that is okay if you label it a P-40C. Granted, it will still be a dog in the late war arenas. However, if it's a P-40C, having the ability to carry a drop tank or bomb should be optional.
Title: Re: P-40B's top speed on the deck.
Post by: Krusty on July 29, 2011, 12:49:00 PM
The question is: If we get a true P-40B... Should we get a true P-40B? What use is it? It almost only ever gets used in the SEA or Tunisia. If we have a P-40C for the desert war with slower performance, shouldn't we get the P-40B that best represents its ues in Asia? The AVG P-40B? The one with more horsepower, but different guns (perhaps) ?

That variant might well be useful with its extra horespower. It would truly even the playing field against Japanese rides we match it up with in scenarios and FSOs, and we'd already have the slower model for exceptions to the rule.
Title: Re: P-40B's top speed on the deck.
Post by: Wmaker on July 29, 2011, 12:56:49 PM
Yep, the P-40C had drop tank shackles hanging in the wind, and weighed considerably more. I have no doubt that the AHII P-40B utilizes P-40C/Tomahawk IIB performance data. Weights seem to confirm this, and that is okay if you label it a P-40C. Granted, it will still be a dog in the late war arenas. However, if it's a P-40C, having the ability to carry a drop tank or bomb should be optional.

Do you have primary source data on the speeds? Btw, AHT lists the weights of the P-40B and P-40C as almost identical. According to its weight data P-40B in AH is between 420-480lbs over weight depending on the configuration.

About that 320mph figure. With plain P-40 without guns (or just the two in the wings) sticking into the wind, no paint and light weight might be behind it. I don't have the actual test report at hand.
Title: Re: P-40B's top speed on the deck.
Post by: Widewing on July 29, 2011, 01:01:08 PM
Various primary sources on the the P-40s... Mostly for the Kittyhawk...

http://www.keyos.org/avia/usa/curtis_tomahawk_p40/manual1.htm (http://www.keyos.org/avia/usa/curtis_tomahawk_p40/manual1.htm)

http://www.ww2aircraft.net/forum/attachments/other-mechanical-systems-tech/46566d1186871182-p-40-flight-manual-p-40d-e.pdf (http://www.ww2aircraft.net/forum/attachments/other-mechanical-systems-tech/46566d1186871182-p-40-flight-manual-p-40d-e.pdf)

http://www.ww2aircraft.net/forum/attachments/flight-test-data/46563d1186864100-p-40-performance-thread-p-40-comparison.pdf (http://www.ww2aircraft.net/forum/attachments/flight-test-data/46563d1186864100-p-40-performance-thread-p-40-comparison.pdf)

http://www.ww2aircraft.net/forum/attachments/flight-test-data/60562d1207343900-p-40-performance-thread-power-setting-p-40-allison-engine.pdf (http://www.ww2aircraft.net/forum/attachments/flight-test-data/60562d1207343900-p-40-performance-thread-power-setting-p-40-allison-engine.pdf)

http://www.ww2aircraft.net/forum/attachments/flight-test-data/62118d1209422596-p-40-performance-thread-p-40-limitations.pdf (http://www.ww2aircraft.net/forum/attachments/flight-test-data/62118d1209422596-p-40-performance-thread-p-40-limitations.pdf)

(http://i1237.photobucket.com/albums/ff480/Tredlite/P-40E-FOIC.jpg?t=1311962972)
Title: Re: P-40B's top speed on the deck.
Post by: Wmaker on July 29, 2011, 01:33:43 PM
Not primary source material but here's some data from a Czech publication:
(http://i46.photobucket.com/albums/f147/Wmaker/P-40data.jpg)

Here it lists P-40C's speed as low as 270mph and P-40B's as 303mph. 33mph difference, ouch! I sure wonder what causes it.

It looks like the closest match for the deck speed is the first production "plain P-40" with its 277mph on the deck. And AHT listed it as high as 320mph based on the speed curve...(based on the assumption that the curve is straight as they seem to be for the Allisons.) :headscratch:

AH's chart for comparison:
(http://bbs.hitechcreations.com/scores/genchart.php?p1=73&p2=-1&pw=2&gtype=0)
Title: Re: P-40B's top speed on the deck.
Post by: Krusty on July 29, 2011, 01:38:13 PM
That makes me wonder: Is that maybe counting the AVG models with more horsepower? Or are they even faster still? I ask because that's faster than a P-40E with WEP.