Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: RODBUSTR on December 02, 2017, 09:07:39 PM
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As stated before the Zeke, and not mentioned yet, The B17. It would be nice to have them more accurately modeled.
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If you like these planes, be careful of what you wish.
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The B-17 did not have WEP.
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Our Zeke didn't have WEP, as explained before.
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The old game Secret Weapons of the Luftwaffe modeled the B-17's engines pretty neatly. If you ran the engines at full power for any length of time, you would damage them. Subsequently they would lose power, then start smoking, then catch on fire. I don't remember if it was Secret Weapons of the Luftwaffe or just a game called "B-17 Flying Fortress", but in one game you could actually dive and put out an engine fire by diving at 300mph.
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The B17E had WEP
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The B17E had WEP
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Do you have any documentation indicating so?
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Yeah give me a few to get it posted. Just woke up from the worlds best nap haha
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This should help you out, it's an interesting read.
http://www.airpages.ru/eng/mn/b17_00.shtml (http://www.airpages.ru/eng/mn/b17_00.shtml)
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Models that were equipped with Wright R-1820-97 nine cylinder Turbo-Supercharged engines (1,200 hp) had WEP (Such as the G model, not the E model), WEP would allow for 1,380 hp at 25,000 feet for short periods of time. Also the stress of over pressure to the manifolds often cracked pistons.
A good read through of the following book might be a good idea:
U.S Warplanes of World War II, pg. 19
Search Goolge under the books section with the exact title mentioned above.
Salute,
Ciaphas AKA Stomplab
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A good read through of the following book might be a good idea:
U.S Warplanes of World War II, pg. 19
Salute,
Ciaphas AKA Stomplab
I prefer using the pilots handbook for the airplane. I flew a B-17 for a couple of years and WEP is something I certainly don't remember being in the book, G model with the -97 engines. Everything is packed now for moving so I can't get to my documents...
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I’m definitely interested in what info you have.
In photos that I have seen, the manifold pressure for wep is controlled by a box mounted above the throttle quad.
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It's been a while so please refresh our memories, why ah Zekes don't have WEP.
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It's been a while so please refresh our memories, why ah Zekes don't have WEP.
Accuracy.
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In photos that I have seen, the manifold pressure for wep is controlled by a box mounted above the throttle quad.
That dial is an electronic turbocharger controller, not for setting WEP but for setting turbochargers to desired setting for the situation. The B-17 I flew had the controller but the turbos had been disconnected. We didn't fly high enough to need them and by disconnecting the ductwork we could get max allowable power without using the turbos. The B-24 still used the turbos but had manual controls for setting boost...a separate lever for each engine.
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FYI not all the information in the training book tells the whole story.
For instance The fuel in any tank is available to any engine supply tank in the airplane through a fuel transfer system consisting of 2 selector valves and an electrical transfer pump.
While it is true you can transfer fuel between tanks it isn't nearly as simple as they make it sound. You can not transfer fuel directly from #1 to #2 or #3 to #4. To transfer fuel to a tank on the same side (say 1 to 2) you first have to transfer that fuel to the opposite wing, either 3 or 4, then pump it back across the airplane.
Also in the fuel system they show for engines 2 and 3 the "fuel tank" and the "feeder tank". While that is how the airplane is built, in use the tanks for #2 and #3 are thought of as a single tank. They are plumbed together, it isn't possible to fill only one of the tanks or draw fuel from only one of them --- they work as a single tank. Transferring fuel was a slow process, the transfer pump ran at a low volume, IIRC it was 12 gallons per minute. Of course if you're coming back from Bremen on two engines and need that fuel moved....
Now one issue that can come up is since there is a fill port on top of the wing for each of the inboard tanks you have to ensure that you fill thru the forward tank otherwise you will think you are full, fuel spills out of fill port, but in fact you've only filled the aft 213 gallon tank. Another issue that I've seen occur was the pilot sticking the tanks to check levels didn't pay attention and stuck both inboard tanks missing the outboard tank (#4 in this case). #4 ran out of fuel before completion of the flying that day.
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That dial is an electronic turbocharger controller, not for setting WEP but for setting turbochargers to desired setting for the situation. The B-17 I flew had the controller but the turbos had been disconnected. We didn't fly high enough to need them and by disconnecting the ductwork we could get max allowable power without using the turbos. The B-24 still used the turbos but had manual controls for setting boost...a separate lever for each engine.
Right, that was what controlled the WEP on the G model. It allowed you to over spin the turbos to gain the extra horsepower needed to supply required thrust at altitudes of 25k or more. Hence the reason it’s called WEP and the reason it’s listed in its specifications.
And that’s literally what WEP does
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Ciaphas, an interesting read but not exactly what I'd call a prime resource/reference. It mentions some procedures to use but not exact RPM/manifold settings. While a few things on the Internet have mentioned the possibility of some kind of B-17G turbocharger "WEP" setting not one that I've read has any specifics, nothing indicates it was used, and our currently modeled speed curve closely matches Boeing's own maximum speed tests.
Let me ask you this: What manifold, RPM, and horsepower corresponds with this 2-minute WEP setting?
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(https://uploads.tapatalk-cdn.com/20171204/37007de33423c856b70c06b892fcfa4f.jpg)
There is the throttle quad with the manifold pressure selector.
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Along with your photo present Hitech with the pertinent documentation if it applies to the version of B17 in our game. Then wait a few years, or keep finding more documentation and presenting it. Have ever considered when he researches the aircraft he builds for his game the lengths he goes to, to be reasonably correct for that model? He won't change anything if that picture is your only evidence as I've seen over 15 years in these forums and playing the game.
Be careful this isn't an opportunity to hide venting at Hitech for not doing things in general you think he has failed at. I went through that with motor cannon not being able to elevate and finding an internal Rehinmetal document about the MK108 ballistics. Still, I went to the trouble over many years to find info to present which can be verified for the MK108 and how specifically motor cannon were mounted in many aircraft in WW2. None of them can be tilted up to change the default IP point from a bore sighting stand.
In short, you need to give him a compelling reason to use your data over his.
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I really don’t see a use for it in the game on this particular aircraft. Was just stating that the misconception that the B-17 didn’t have WEP was not true.
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Hmmm. That placard certainly shows a WEP power setting. I truly don't remember that in the -17 I have time in -- it had the placard, I just don't remember the WEP. It has been 15 years since I've flown the airplane. I'll have to dig thru some pics and see if I have one showing the throttles in Nine Oh Nine.
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You said the manifold pressure box was disabled, that could have been because the need for WEP isn’t needed anymore but more honestly in my opinion I think that it probably shelled more engines than it did good as running WEP on any engine for prolonged periods of time would end up requiring a full tear down and replacement of stressed components and on a four engine airframe it was probably not beneficial operationally and for maintenance crews as engine phase inspections are very tedious an often require major component replacement depending on the hours flown on each engine.
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Okay, you need to realize that the turbo controller is there to adjust the turbo waste gates in order to obtain the desired manifold pressure during normal operation of the aircraft.....it is not there to enable WEP.
I didn't say the Controller was disabled, I said the turbo ducting had been disconnected which renders the turbos useless. As for need, it would have been nice to have the turbos coming out of West Yellowstone with a density altitude around 7000'. :)
Speaking of turbos (http://www.dalefalk.com/Movies/Bombers/i-fHx5CSQ)
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Right and opening the waste gate up or wide open is what allows the manifold pressure to climb to sufficient pressure to obtain the WEP hp that is listed
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The manifold pressure selector dial regulates the amount of air flow to the manifold thus regulating the power output of the engines. Many of these manifold control boxes had a lockout feature that prevented it from being accidentally switched to full open.
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Right and opening the waste gate up or wide open is what allows the manifold pressure to climb to sufficient pressure to obtain the WEP hp that is listed
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Wrong. Opening the waste gate bypasses the turbo. To increase manifold pressure you close the waste gate forcing exhaust gasses through the turbo spinning up the turbo which pumps more air into the engine. More air means you can use more fuel. More fuel means more power.
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Hmmm. That placard certainly shows a WEP power setting. I truly don't remember that in the -17 I have time in -- it had the placard, I just don't remember the WEP. It has been 15 years since I've flown the airplane. I'll have to dig thru some pics and see if I have one showing the throttles in Nine Oh Nine.
This would be akin to augmented thrust. Emergency use only for something like an engine failure on takeoff. Is this a factory placard or a modern add-on?
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Interesting that the B-17 could "HOVER". I thought only the Tu-2s could do that. :D
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Col, this is 909's throttle quadrant placard. You were correct that you never saw a WEP setting
(http://www.acksite.com/17post/power_settings.jpg)
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Col, this is 909's throttle quadrant placard. You were correct that you never saw a WEP setting
(http://www.acksite.com/17post/power_settings.jpg)
As I mentioned, the first one could be apocryphal, i.e. unoriginal. Then again, so could this one be. Or both. Or neither. :headscratch:
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Perhaps only a small set were outfitted with it and the option was deemed impractical and was discontinued as it had no real value to the operation of the aircraft.
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I have to ask if that image is from a video game? if not, photographer has mad skills.
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I have to ask if that image is from a video game? if not, photographer has mad skills.
That was my original reaction. “Hmmmm. IL-2 graphics?”
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FLS there is a place on the model 52 dash schematics where it is shown. I good place to reference That is The Great Book of World War Two Airplanes. There is a great foldout 2 page picture of the cockpit of the Model 52. It looks like there is a place on the AH Zeke where It is supposed to be also. Top left side near close to the throttle quadrant....Accuracy? Also My knowledge of WEP for the Forts comes from books I've read and N.A.C.A. statistics.
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I haven't seen anything that indicates the A6M5b should have WEP.
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Most likely our version in-game performs better than many did in WW2 due to fuel issues later on. For what it's worth, when you can barely run 87 octane and your fuels from 1944 onward were thinned out with tree-sap-turpentine, WEPs really a kind of pipe dream.
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Well look at he book I mentioned and You will.
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You mean "The Great Book of World War Two Airplanes"...? Not to disparage the book, but I think it may not be the best resource on the matter.
Many planes had missing instrument slots or things that were planned but not available. Hell, Japanese zeroes often had no radios to speak of. They still had radio compartments. Soviets hard cardboard radios on their plans and schematics but almost to a plane were thrown out to save weight because they just didn't work.
Do you realize that the A6M3 model 32 had the same engine as the A6M5b model 52? They both ran the same engine, the Sakai 21, and had the same horsepower rating. Different exhaust configurations and other changes improved the overall plane performance, but it had the same engine.
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Well look at he book I mentioned and You will.
A later model, the A6M6c, with a different engine, had WEP. The AH3 model is correct.
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Almost no -6cs were made. It's debatable if any ever flew in actual service. The A6M5 series was the last widely produced and used version, though A6M8 production was supposedly ramping up (They skipped the 6 and 7 models, basically).
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well not according to the book I mentioned.
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well not according to the book I mentioned.
One book of questionable accuracy...
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Rod, you remember that comment I made before? I'll say it again: You're passionate about it, and that's a good thing. You just need to do more research and find better sources for your information before you just accept whatever happens to coincide with what you want the answer to be.
Just because a book is printed doesn't mean it's factual, it's correct, or the author is credible. There are many that are just wrong, present wrong information, or even make up information and/or reprint debunked mistakes because they didn't have a proper research or review process when they made that book. Remember this: The ultimate end-point of writing a book and having it published is to SELL the book. If that means skimping on fact checking and getting things wrong means you get your income checks, maybe that explains some of the very sloppy books on WW2 aviation out there.
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A later model, the A6M6c, with a different engine, had WEP. The AH3 model is correct.
+1 on this - Mitsubishi Zero: Japan's Legendary Fighter (book by Peter Charles Smith) confirms this as it went in great lengths to explain the variants and improvements with each model. Couple of points:
1. The years of service of our A6M5b means it was a pre-WEP model
2. The IJN had issues getting it to work properly until early 1945
3. Ours is a August 1943 variant, and by then, the IJA and IJN were in deep trouble producing anything, let alone developing the performance of their aircraft. And even then, there were not too many WEP models out there - if they worked at all.
Page 163: Engine boost system
While the Zero herself had been steadily improved, lack of a really powerful engine continued to restrict just what improvements could be made to the existing airframe, which these additions had now increased by 700lb (3.175 kg) additional weight with the same power plant. Mitsubishi required the Navy air arsenal allow them to fit the more powerful Mitsubishi Kinsei-62 radial to this aircraft, but the request was rejected outright. The Navy's solution was to insist on fitting the existing Sake-21 with a water-methanol injection system to boost its output for short bursts during combat.21 However, such was the slow pace of development of this system that the HEI had to go into combat without it. Eventually one trial aircraft appeared late in 1944 fitted with the Sake-31a radial. It was far from successful prototype; the injection system was still in its experimental stage and was plagued with continual problems, while the modified engine generated less power not more. The A6M5c sub-type was built at the Nakajima Koizuma Plant, and attained a maximum speed of 346mph (556.83km/h) but only ninety-three ever appeared before the whole project was cancelled in the increasingly frenetic situation the Navy found itself that winter of the war. Production was complex and still mired by problems, maintenance of the temperamental power plant in the field difficult.
Work on the water-methanol injection system continued, however, utilizing the Nakajima Sakae-31 engine, which was a fourteen-cylinder, air-cooled radial, which was rated at 1,130hp (831.11kW) for take-off, (1,100hp (809kW)at 9,350ft (2,850m) and 980hp (720.79kW) at 19,685ft (6,000m).