Let's talk the P-51 in combat in DCS - Page 26 - ED Forums
 


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Old 02-11-2020, 07:57 PM   #251
grafspee
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Originally Posted by MadCat1381 View Post
I don't argue this.
But the AAF would not have written this in one of their manuals, if it wasn't a factor at all.
I don't know why they did this or not mentioned it in other manuals, but they must hve had a reason to do it.

And I guess that the 51-127-5 is where ED got this information from.
Lets think, if use of WEP below 5000 ft would be real risk for engine, i think it would be stated in any other manuals too, I don't know why this information isnt mentioned in other manuals where other stuff related to WEP is.
For me mystery is this That WEP provide no gain below 5000 ft. This is mystery for me hehe
Another though, if it was restriction type thing it would look like this "WEP use below 5000 ft is forbidden" this line in manual is mystery for me
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Old 02-12-2020, 09:03 AM   #252
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Folks,


your are both right. Read the entire passage in 51-127-5. The limit ist in regard to early production planes, where you had no "gate" at the throttle like the DCS P-51D has.
On those early planes you could reach more than 61" inches at low altitude just by pushing the throttle to far foward. So you could "gain" 67" inches WEP MP without pulling the control lever mentioned in the passage. Probably you could get even more than 67" inches, depending on how the throttle was rigged on those early planes.

The manifold pressure regulator connected to the throttle changed a couple of times during the service life of the Mustang and got more sofisticated. Later when you pushed the throttle full foward but not through the gate, the regulator would make sure you do not exceed 61".


This limitation is quite common on early planes of that period and it is one of the things you have to keep in mind when lining them up for take-off cause if you just shove the throttle to the stop you will overboost the engine.
This can also happen at altitude if the supercharger gear changes and you forget to reduce MP to a safe limit before it switches to high gear, from memory the F4U is one of the planes where that could happened. Just take a look at the WW2 US training films for it. It should be mentioned in them somewhere.
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Old 02-13-2020, 07:15 AM   #253
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Originally Posted by Agathos_Deimon View Post
Folks,


your are both right. Read the entire passage in 51-127-5. The limit ist in regard to early production planes, where you had no "gate" at the throttle like the DCS P-51D has.
On those early planes you could reach more than 61" inches at low altitude just by pushing the throttle to far foward. So you could "gain" 67" inches WEP MP without pulling the control lever mentioned in the passage. Probably you could get even more than 67" inches, depending on how the throttle was rigged on those early planes.

The manifold pressure regulator connected to the throttle changed a couple of times during the service life of the Mustang and got more sofisticated. Later when you pushed the throttle full foward but not through the gate, the regulator would make sure you do not exceed 61".


This limitation is quite common on early planes of that period and it is one of the things you have to keep in mind when lining them up for take-off cause if you just shove the throttle to the stop you will overboost the engine.
This can also happen at altitude if the supercharger gear changes and you forget to reduce MP to a safe limit before it switches to high gear, from memory the F4U is one of the planes where that could happened. Just take a look at the WW2 US training films for it. It should be mentioned in them somewhere.
That makes sense.
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Old 02-15-2020, 09:56 PM   #254
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I have done these three tests:

1) I started my test at 10 000 ft with both coolers in green. Then I started to increase RPM to 3000 and MP to 61" + WEP = cca 63-65" and fly this for 4 minutes. I did not allow coolers much out of green (controlled them manually if needed) and never allowed them to cross the red mark. After 4 mins of WEP I decrease MP to 46" and RPM to 2700. Then I continued to fly for another 20 minutes with this cruise setting without any problem.

2) The same as above but this time with checked "Random system failures" (Settings - Misc.). Again, no problem at all for 20 min after using WEP.

3) The same as 2) but this time in the altitude of only 3 000 ft. In this altitude, I have precisely MP 67" thanks to the WEP. And again, for 20 mins after using WEP no problem at all.

My conclusion: using WEP is safe in case the pilot do not allow temps of the coolers to rise outside green.
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Old 02-16-2020, 09:51 AM   #255
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Quote:
Originally Posted by tapi View Post
I have done these three tests:

1) I started my test at 10 000 ft with both coolers in green. Then I started to increase RPM to 3000 and MP to 61" + WEP = cca 63-65" and fly this for 4 minutes. I did not allow coolers much out of green (controlled them manually if needed) and never allowed them to cross the red mark. After 4 mins of WEP I decrease MP to 46" and RPM to 2700. Then I continued to fly for another 20 minutes with this cruise setting without any problem.

2) The same as above but this time with checked "Random system failures" (Settings - Misc.). Again, no problem at all for 20 min after using WEP.

3) The same as 2) but this time in the altitude of only 3 000 ft. In this altitude, I have precisely MP 67" thanks to the WEP. And again, for 20 mins after using WEP no problem at all.

My conclusion: using WEP is safe in case the pilot do not allow temps of the coolers to rise outside green.
while wep is generally safe for me a single flight i find that often its after i land, rearm and take off that i have issues with engine randomly dying, so maybe it has something to do with the temp difference when landing, at idle the temps drop very fast when on approach.
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Old 02-16-2020, 10:15 AM   #256
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Quote:
using WEP is safe
Maybe the patch fixed it? Are you running v2.5.6?
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Old 02-16-2020, 10:16 AM   #257
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Nope, tested it in 2.5.5
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Old 02-16-2020, 12:10 PM   #258
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Hmmm. These wildly differing pilot experiences of it are really flummoxing. Why does it work for some and not for others?
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Old 02-16-2020, 12:40 PM   #259
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Originally Posted by msalama View Post
Hmmm. These wildly differing pilot experiences of it are really flummoxing. Why does it work for some and not for others?
He didn't hit 67" in tests, oh he did in 3rd test
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Old 02-17-2020, 09:38 PM   #260
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I’ve found that using WEP can be a little hit and miss; for the most part I don’t have issues with it as long as I stay fast, enough to keep temps from going above red line. Every so often it will go bang on me while flying fast and I’ve yet to determine the cause. Speaking of things breaking, did the new DM go live? I accidentally crashed while testing the new sounds and saw a bunch of equipment failures that I didn’t know could fail.
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