Author Topic: F4F-4 vs Zero 21 (Read 4341 times)

F4UDOA · « **Reply #60 on:** February 19, 2003, 06:11:49 PM »

Brady,

Which book do you have? I am looking for the more data than what is in the book I have.

I have a feeling we are reading the book.

brady · « **Reply #61 on:** February 19, 2003, 06:38:44 PM »

The Book I have that quotes the flight test data, and does so verbatium, from the link you posted F4UDOA, is : Zero Fighter By Robet C. Mikesh Crown publishing 1981.

Arlo · « **Reply #62 on:** February 19, 2003, 06:41:49 PM »

Hehe ... that "cracked" me up.

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Originally posted by brady

5) I am on crack and the figures are right

Widewing · « **Reply #63 on:** February 19, 2003, 07:31:10 PM »

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Originally posted by brady
Ok, check out this spead chart for AH planes, and keep this statement in mind:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

What is wrong in AH Why the descrepency?

The java based chart you provided does not accurately reflect any of the speed at altitude charts I have for the F4F-4, especially above 17,000 feet. At 30k, airspeed should be 280 mph TAS. At 22.5k, airspeed should be 309 mph, not 293.

The AH speed chart conforms to those I have, and one you have in America's Hundred Thousand. I think AH got this one right.

Furthermore, I question the Zero's chart simply because the Sakai radial made only 415 hp at 30k, not nearly enough to sustain 310 mph up that high. Yet, the F4F-4's R-1830 was making 650 hp at that altitude. I realize this is the same curve as the AH chart, but I can't ignore the troubling lack of horsepower available without some second, unimpeachable source of data.

My regards,

Widewing

Widewing · « **Reply #64 on:** February 19, 2003, 07:56:50 PM »

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Originally posted by brady
Squire,

"I cant understand why you keep asserting that the F4F-4 in the data I included was a late model"

I am not, I am stating that in America's 100K they say that it was the speed for the late model.

"The late model F4Fs could do 280 on the deck "with nuetral blower" yes, thats referring to the F4F-8 (FM-2) with wep. With the blower engaged it could do near 300, as it does in AH. "

America's Hundred Thousand says, and I quote, "Late Wildcats could make about 285 to 295 mph in MILITARY power at sea level,"
Pg. 473, lower right paragraph.

It's referring to the F4F-4/FM-1 and FM-2 respectively. So, it seems that the AH model is accurate for both. Be content that they didn't select the F4F-3, which was faster than the Zero at its best altitude and climbed even better than the FM-2.

Accept it, the Zero 21 was a slug..

My regards,

Widewing

brady · « **Reply #65 on:** February 19, 2003, 07:58:10 PM »

That still doesent realy clear up the deck spead issue with the Wildcat howeaver.

Since 95% of all combat in AH takes place bellow 10K, and 90% bellow 5k, that is my primary area of concern/ interest at present.

The whole point of this spead debat is derived from the evnets that took place on that day in Augast 1942, aparently HTC does not except such test flights as revelent, or so I have been told. The results of this test caused me to look at the speads of the Wildcat and in so doing I found some questionable evidance as to the sea leval spead, and general preformance issues regarding the two planes bellow 5,000 feat.

The deck spead of the F4F-4 is not 100% clear. It apears that acording to the test it should be slower, and Americas 100K is not to clear on this as well.

Widewing · « **Reply #66 on:** February 19, 2003, 11:11:02 PM »

Quote

Originally posted by brady
That still doesent realy clear up the deck spead issue with the Wildcat howeaver.

Since 95% of all combat in AH takes place bellow 10K, and 90% bellow 5k, that is my primary area of concern/ interest at present.

The deck spead of the F4F-4 is not 100% clear. It apears that acording to the test it should be slower, and Americas 100K is not to clear on this as well.

Examine the speed graphs on page 473, graph 40 and page 595, graph 77A. They clearly define sea level max speed of the F4F-4 as 285 mph at MIL power.

My regards,

Widewing

brady · « **Reply #67 on:** February 20, 2003, 12:19:18 AM »

But:

The book also states:

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473) "

Late model as defined elswhear is not a F4F-4.

Bellow we have the statment for the Testing in San Deigo, with a F4F-4 and the A6M2:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed"

So hear in lies the dispute, Why was the testflight different. Why the descrepency on the speads, what model of F4F is the chart refering to.

Why the differances in preformance between 1,000 and 5,000ft?

joeblogs · « **Reply #68 on:** February 20, 2003, 08:18:42 AM »

Brady - where did that chart come from?
What program is that?
-Blogs

Quote

Originally posted by brady
Ok, check out this spead chart for AH planes, and keep this statement in mind:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed."

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473)"

What is wrong in AH Why the descrepency?

brady · « **Reply #69 on:** February 20, 2003, 10:54:32 AM »

I used to have a link to it but I misslyed it:(, It was done by a player, and fairly accurate, a Nice source to get you the feal for how planes preform in AH.

Puke · « **Reply #70 on:** February 20, 2003, 11:15:42 AM »

This chart?

http://www.jannousiainen.net/online_sims/jg_4/index.htm

You have to scroll to the bottom of the page though.

Widewing · « **Reply #71 on:** February 20, 2003, 12:54:03 PM »

Quote

Originally posted by brady
But:

The book also states:

"Americas 100k states that Late model Wildcats could make about 285 mph on the deck "With Military Power". (p. 473) "

Late model as defined elswhear is not a F4F-4.

Bellow we have the statment for the Testing in San Deigo, with a F4F-4 and the A6M2:

"Close to sea level, with the F4F-4 in neutrail blower, the two planes were equil in leval speed"

So hear in lies the dispute, Why was the testflight different. Why the descrepency on the speads, what model of F4F is the chart refering to.

Why the differances in preformance between 1,000 and 5,000ft?

Brady, I have already told you the the charts SPECIFICALLY refer to the F4F-4. It's annotated. Each type has its own curve and each is annotated.

Here's the quote again so that there is no misunderstanding:
"Late Wildcats could make about 285 to 295 mph in MILITARY power at sea level," This statement conforms to the charts. There is nothing to debate about this, it's there in black and white for all to see.

Now, when the Zero was tested in San Diego, did they test it with captured Japanese 87 octane avgas, or did they use the U.S. standard grade 100/130 octane avgas?

Something not mentioned is the fact that the F4F-4 pilot can engage low or even high blower, over-boost the engine and gain considerable speed over neutral blower. So could the Zero pilot, if and only if he had high octane fuel to minimize detonation. Burning that Japanese dishwater, I'd bet he melts pistons in 60 seconds. The F4F pilot may eventually damage his engine. But, the Zero pilot absolutely will damage his engine (unless he has the 100/130 avgas).

Remember, I'm not arguing that the Zero isn't porked. I'm arguing the F4F-4 IS accurately modeled. I feel that the A6M2 as modeled in AH does not live up to its reputation. But, then again, in the real world it didn't either, at least after Allied pilots discovered its weaknesses.

My regards,

Widewing

brady · « **Reply #72 on:** February 20, 2003, 01:04:15 PM »

Ya thats it awsome chart.

HoHun · « **Reply #73 on:** December 29, 2004, 08:36:26 PM »

Hi everyone,

I'm currently trying to figure out the Grumman fighters' performance. One information I can't seem to find is the gear ratio for the R-1820-56 used in the FM-2. It seems there were variants of the R-1820 with a 16:9 ratio as well as others with a 3:2 ratio.

The 16:9 ratio would appear to make more sense than the 3:2 ratio, but the FM-2 manual has a comment on not using more than 2500 rpm in the climb above 20500 ft due to propeller efficiency losses that suggests the 3:2 ratio might have been used.

Could anyone please help me with this information? :-) Thanks in advance!

Regards,

Henning (HoHun)

FDutchmn · « **Reply #74 on:** December 29, 2004, 11:00:28 PM »

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Originally posted by brady
with the exception that the Zeros engine cut out in in pushovers

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Originally posted by thrila
Sorta like the spit I and hurri I?

Didn't know the zero had problems like that.

No, the Zero didn't have this problem. It is thought that the American engineers assembled the carburator wrong. The design of the carburator was such that it did feed gas even under negative Gs. With extensive documentation on the Zero in Japan, this issue is not noted in any of them. I will post a diagram of how it worked later... I got to go find it first.