Author Topic: Perked USAAF plane?  (Read 2822 times)

Offline Captain Virgil Hilts

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Re: Perked USAAF plane?
« Reply #75 on: September 23, 2009, 06:11:54 PM »
I'll be happy to let you prove that statement. Until then, most, if not all, reputable sources put the P-38L at 414 mph and the P-51H at 490 mph

Most sources use military power for the P-38L, and never give a spec for it at War Emergency Power. In fact, I'll let you drag out any chart that shows a P-38L having a top speed of 414MPH at WEP. Because I've never seen a chart that lists that. They all show the P-38L between 412MPH and 420MPH at military power, not WEP. Do you really think the P-38L is slower than the P-38J, despite having considerably more power and very little more weight?

I have no need to prove that statement, others have proven it several times over, here and elsewhere. And there likely is no more reputable source on the P-38 than Bodie, he had access to every piece of data, as well as working with, for decades, the engineers and staff who ran the P-38 project, including the man behind the plane, Clarence "Kelly" Johnson.
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

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Offline Ack-Ack

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Re: Perked USAAF plane?
« Reply #76 on: September 23, 2009, 06:44:48 PM »
I'll be happy to let you prove that statement. Until then, most, if not all, reputable sources put the P-38L at 414 mph and the P-51H at 490 mph

IIRC, the P-38L was capable of 443MPH TAS at 28,000ft with WEP.


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Offline SmokinLoon

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Re: Perked USAAF plane?
« Reply #77 on: September 23, 2009, 07:04:40 PM »
Meanwhile, we're running the BoB without the He-111, again.

I agree.  We dont *need* any more US aircraft atm, imo.  YMMV.  :)
Proud grandson of the late Lt. Col. Darrell M. "Bud" Gray, USAF (ret.), B24D pilot, 5th BG/72nd BS. 28 combat missions within the "slot", PTO.

Offline BnZs

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Re: Perked USAAF plane?
« Reply #78 on: September 23, 2009, 08:31:57 PM »
I agree.  We dont *need* any more US aircraft atm, imo.  YMMV.  :)


We don't *need*AHII, microwave popcorn, or internet porn, but...
"Crikey, sir. I'm looking forward to today. Up diddly up, down diddly down, whoops, poop, twiddly dee - decent scrap with the fiendish Red Baron - bit of a jolly old crash landing behind enemy lines - capture, torture, escape, and then back home in time for tea and medals."

Offline Rebel

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Re: Perked USAAF plane?
« Reply #79 on: September 23, 2009, 10:12:01 PM »
P-47M - a D-25 with the N's motor, and sans pylons.  Thing would SCREAM down low, and even better up high. 

B-29 - hate to say it (poor kitten), but it'd be a helluva addition, perkable too.

P-51H- never saw combat-combat, but it wasn't for lack of tryin.   This one was just outrageously fast. 

P-63 - you could make an argument for this one.  Bad bellybutton plane.

Those are really about your only options.  P61 would be fun, but it was a night fighter.  Very agile, and pretty quick, but nothing out of this world.

What I'd love to see is P47M, the 150 octane fuel for all USAAF birds (with perk price, of course), and the Mosquito updated and remodeled without those exhaust shrouds- should pick up a significant amount of speed. Maybe a revisit to the Mustang wing model and the clMax problem that it has (Widewing has had some spectacular information presented about it).
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Offline Anaxogoras

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Re: Perked USAAF plane?
« Reply #80 on: September 24, 2009, 06:07:37 AM »
Most sources use military power for the P-38L, and never give a spec for it at War Emergency Power. In fact, I'll let you drag out any chart that shows a P-38L having a top speed of 414MPH at WEP. Because I've never seen a chart that lists that. They all show the P-38L between 412MPH and 420MPH at military power, not WEP. Do you really think the P-38L is slower than the P-38J, despite having considerably more power and very little more weight?

I have no need to prove that statement, others have proven it several times over, here and elsewhere. And there likely is no more reputable source on the P-38 than Bodie, he had access to every piece of data, as well as working with, for decades, the engineers and staff who ran the P-38 project, including the man behind the plane, Clarence "Kelly" Johnson.

Can you be my rhetoric teacher?  Pretty please? :P

IIRC, the P-38L was capable of 443MPH TAS at 28,000ft with WEP.

It would be great to see a source for this.



Il-2 has two P-38Ls, one of which they call "P-38LLate."  The normal P-38L is comparable to ours, and the late P-38L does about 430mph at 26,600ft.  Did all P-38Ls receive the same engines?
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Offline Captain Virgil Hilts

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Re: Perked USAAF plane?
« Reply #81 on: September 24, 2009, 09:05:34 AM »
IL 2 is wrong. All P-38L models, beginning with the P-38L-1-Lo, were fitted with the Allison V-1710-F30. The preceding P-38J models, from the P-38J-1-Lo were equipped with the Allison V-1710-F17. The V-1710-F17 was rated at 1600HP at WEP, where as the V-1710-F30 was rated at 1725HP at WEP, for a difference of 125HP per engine, or 250HP per plane. The P-38J was rated at 421MPH at WEP, with 250HP less than the P-38L. It would be odd to say the least that a nearly identical plane with a very small increase in weight and a 250HP increase would be as slow or slower.

As a side note, in 1943, Allison developed the V-1710-G6 series engines. These engines were rated at 1725HP at military power with a two speed two stage supercharger and 2250HP at WEP with 100" of boost on water/methanol injection and 115/145 fuel. That was without the benefit of a turbocharger.

That AHII chart, by the way, is a chart for planes in a game, where as the discussion was about real aircraft.
« Last Edit: September 24, 2009, 09:07:23 AM by Captain Virgil Hilts »
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

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Offline Captain Virgil Hilts

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Re: Perked USAAF plane?
« Reply #82 on: September 24, 2009, 09:34:57 AM »
The source for the top speed of the P-38L would be "The Lockheed P-38 Lightning" by Warren Bodie, widely accepted as the bible of P-38 sources. On page 215 Bodie states that a P-38L-5-Lo was probably capable of 443MPH TAS  at 20,000 to 23,000 feet. Further, on page 213, he states that a formal test report signed by General Franklin O. Carroll read:

Maximum HP at 60.8" MAP and 3,000 RPM was 1612HP at critical altitude.
Maximum sea level speed was  345MPH
Maximum critical alt. speed was 421.5 MPH (WEP) (25,800ft)
ROC at sea level was 4000fpm
ROC at critical altitude was 2900fpm (23,400ft)
Time to critical altitude was 6.19 minutes (23,400ft)

So odds are, a P-38L, with 250HP more at WEP than a P-38J, would not have the same top speed or slower top speed at WEP as that P-38J.
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

SaVaGe


Offline Anaxogoras

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Re: Perked USAAF plane?
« Reply #83 on: September 24, 2009, 10:16:33 AM »
That's good data, thank you.  I'm curious to know why the P-38L isn't faster at altitude in game.
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Offline B3YT

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Re: Perked USAAF plane?
« Reply #84 on: September 24, 2009, 10:55:22 AM »
Which once again never actually saw combat.

You're opening up a RIDICULOUS can of worms if you start to let stuff in like that.

I think HTC has the right approach, and that means just-a-bit-too-late birds like the P-51H, Meteor, F7F and F8F don't have a place in the game.

Shamrock,

WILL YOU STOP POSTING? The US Navy didn't even HAVE the F6F or TBM at Coral Sea. The TBM didn't see its first combat (only SIX of them at that) until Midway. The F6F didn't until September 1943.


the Meteor DID see combat over Holland  in ground attack sorties; they even had to fight against P51's when mistaken for 262 buy USAAF crews.   It just never took part in fighter sweeps and was never credited with AIR to AIR kills though they did have over 250 credits for A/C destroyed on the ground as well as V1 kills .
As the cleaners say :"once more unto the bleach"

Offline Captain Virgil Hilts

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Re: Perked USAAF plane?
« Reply #85 on: September 24, 2009, 11:19:34 AM »
That's good data, thank you.  I'm curious to know why the P-38L isn't faster at altitude in game.

Because HTC made a conscious decision to follow the mainstream, where the P-38L is not rated as being faster than the P-38J. Again, the USAAF, at least in Europe, officially, did not use the higher RPM and higher boost settings that Lockheed and Allison provided. The V-1710 F-30 was a different engine than the V-1710 F-17, and capable of higher boost as well as higher RPM. The USAAF did not see it that way. Lockheed and Allison field representatives, sent to Europe to help USAAF personnel work with the P-38 showed the personnel at group and squadron level how to use the correct tune up on the F-30 engines. Lockheed and Allison field representatives went to Europe repeatedly between 1943 and 1945 both to offer technical support and also to inquire about needed improvements.

The V-1710G series engines were eventually installed in the F-82 "Twin Mustang". So those high power ratings were used in combat, those were combat rated and combat ready engines, and they were not substantially changed after 1943.
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

SaVaGe


Offline PJ_Godzilla

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Re: Perked USAAF plane?
« Reply #86 on: September 24, 2009, 12:39:45 PM »
Because HTC made a conscious decision to follow the mainstream, where the P-38L is not rated as being faster than the P-38J. Again, the USAAF, at least in Europe, officially, did not use the higher RPM and higher boost settings that Lockheed and Allison provided. The V-1710 F-30 was a different engine than the V-1710 F-17, and capable of higher boost as well as higher RPM. The USAAF did not see it that way. Lockheed and Allison field representatives, sent to Europe to help USAAF personnel work with the P-38 showed the personnel at group and squadron level how to use the correct tune up on the F-30 engines. Lockheed and Allison field representatives went to Europe repeatedly between 1943 and 1945 both to offer technical support and also to inquire about needed improvements.

The V-1710G series engines were eventually installed in the F-82 "Twin Mustang". So those high power ratings were used in combat, those were combat rated and combat ready engines, and they were not substantially changed after 1943.

Fascinating, yet you'd think that Lockheed (pbu Johnson) and Allison wouldn't have developed the V-30 and the L version to house same out of the goodness of their hearts. I.E., if the USAAF hadn't requested the update, or been sold on the update by Lockheed, then why did Lockheed develop it?

Further, if indeed the USAAF had requested those changes or ordered up those changes as proposed, why not then use the higher RPM and boost settings? And what does the latter entail? Is it a calibration to the pilot's controls that is required (much like we map and engine throttle to pedal deflection in today's cars)? What about the factory settings? Surely the L was delivered to design...

Please elaborate. You've picqued my curiosity on this one.

Incidentally, I'm guessing "the 1000 plane raid" or one of it's pseudonyms, as the Avatar...
Some say revenge is a dish best served cold. I say it's usually best served hot, chunky, and foaming. Eventually, you will all die in my vengeance vomit firestorm.

Offline Captain Virgil Hilts

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Re: Perked USAAF plane?
« Reply #87 on: September 24, 2009, 01:27:57 PM »
Fascinating, yet you'd think that Lockheed (pbu Johnson) and Allison wouldn't have developed the V-30 and the L version to house same out of the goodness of their hearts. I.E., if the USAAF hadn't requested the update, or been sold on the update by Lockheed, then why did Lockheed develop it?

Further, if indeed the USAAF had requested those changes or ordered up those changes as proposed, why not then use the higher RPM and boost settings? And what does the latter entail? Is it a calibration to the pilot's controls that is required (much like we map and engine throttle to pedal deflection in today's cars)? What about the factory settings? Surely the L was delivered to design...

Please elaborate. You've picqued my curiosity on this one.

Incidentally, I'm guessing "the 1000 plane raid" or one of it's pseudonyms, as the Avatar...

It was during war. Lockheed and Allison were always trying to improve their product, just as everyone else was. Both for profit and for the war effort.

The USAAF was I'm sure concerned with longevity and reliability. The harder you push your parts, the more often they require maintenance or replacement. However, it is much cheaper to replace engines or even planes that it is trained pilots. The P-38L was delivered according to USAAF specification, not necessarily Lockheed/Allison specification.

In order to increase MAP, you must increase throttle opening, or change the wastegate setting. In order to increase RPM, you must alter the pitch of the propeller. While wires were used to prevent the throttles from going past military power, and you had to break those wires to get to WEP, other adjustments prevented the throttle from going even further, either mechanical stops or cable length adjustments. So to get more MAP, you adjust either the cables or the stops, or both. In the case of the P-38, it was saddled with the Curtiss Electric propellers. These were electrically governed for speed. They were controlled by voltage or amperage, so you'd have to adjust the pitch control to provide the necessary RPM. Loss of electrical power would cause the propellers to "run away' meaning they'd exceed the correct RPM.

The avatar, like the signature, comes from "The Great Escape". It's Steve McQueen in the role of Captain Virgil Hilts, a "hot shot pilot" who was shot down and ended up a POW.
"I haven't seen Berlin yet, from the ground or the air, and I plan on doing both, BEFORE the war is over."

SaVaGe


Offline PJ_Godzilla

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Re: Perked USAAF plane?
« Reply #88 on: September 24, 2009, 01:35:22 PM »
It was during war. Lockheed and Allison were always trying to improve their product, just as everyone else was. Both for profit and for the war effort.

The USAAF was I'm sure concerned with longevity and reliability. The harder you push your parts, the more often they require maintenance or replacement. However, it is much cheaper to replace engines or even planes that it is trained pilots. The P-38L was delivered according to USAAF specification, not necessarily Lockheed/Allison specification.

In order to increase MAP, you must increase throttle opening, or change the wastegate setting. In order to increase RPM, you must alter the pitch of the propeller. While wires were used to prevent the throttles from going past military power, and you had to break those wires to get to WEP, other adjustments prevented the throttle from going even further, either mechanical stops or cable length adjustments. So to get more MAP, you adjust either the cables or the stops, or both. In the case of the P-38, it was saddled with the Curtiss Electric propellers. These were electrically governed for speed. They were controlled by voltage or amperage, so you'd have to adjust the pitch control to provide the necessary RPM. Loss of electrical power would cause the propellers to "run away' meaning they'd exceed the correct RPM.

The avatar, like the signature, comes from "The Great Escape". It's Steve McQueen in the role of Captain Virgil Hilts, a "hot shot pilot" who was shot down and ended up a POW.

I should've known. The 1000 plane raid was also McQueen, of course, but was not nearly as popular. I've seen 'em both.
Some say revenge is a dish best served cold. I say it's usually best served hot, chunky, and foaming. Eventually, you will all die in my vengeance vomit firestorm.

Offline Saurdaukar

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Re: Perked USAAF plane?
« Reply #89 on: September 25, 2009, 12:21:58 PM »
Bearcat or Tigercat would be interesting as exceptions....but they would do nothing for getting a perked USAAF airplane into the game as they were both Navy/Marine birds, and we already have a couple perked US Navy/Marine birds.

Good point.  Didnt read close enough.

...can we have the Bearcat anyway?

(Great article in this month's Air & Space on Rare Bear.  PW3350 @ 4,500HP.  Set piston-driven speed record of like 538MPH or something)   :confused: