dear Yo-Yo, is there any way, to use WEP, and maintain a reliable engine?

ok the title says it all....

after about one and a half year, the effective use of WEP is still a mystery to me, and i know that im by far not the only one...in fact i have not yet met one person who knows the answer...

of course i got away with it from time to time with using WEP,..but most of the times, after using WEP, even for short periods well below the 5min tolerance, the engine will die at some point, even when the temps were in the healthy ranges...quite often it dies when i already throttled back to 46 @3000 or even 36@2400.

temps are ok, and all of a sudden the engine stops, sometimes instantly, sometimes slowly...funny thing is, that all of a sudden, the coolant temperature jumps to max(there is no increase, but its a sudden jump from green to max)

it seems, that as soon as you activate WEP, the engine will die at some point no matter what, and no matter how careful you treated it....

please Yo-Yo, can you share some light on it?can you give us instructions on how to use it reliable?is there any reliable way at all?

ok the title says it all....

after about one and a half year, the effective use of WEP is still a mystery to me, and i know that im by far not the only one...in fact i have not yet met one person who knows the answer...

 

of course i got away with it from time to time with using WEP,..but most of the times, after using WEP, even for short periods well below the 5min tolerance, the engine will die at some point, even when the temps were in the healthy ranges...quite often it dies when i already throttled back to 46 @3000 or even 36@2400.

temps are ok, and all of a sudden the engine stops, sometimes instantly, sometimes slowly...funny thing is, that all of a sudden, the coolant temperature jumps to max(there is no increase, but its a sudden jump from green to max)

 

it seems, that as soon as you activate WEP, the engine will die at some point no matter what, and no matter how careful you treated it....

 

please Yo-Yo, can you share some light on it?can you give us instructions on how to use it reliable?is there any reliable way at all?

Have you tried flying the Mustang with the Radiator fully open (Manually).

And keeping your airspeed up, for example don't climb for to long with a lot of Throttle applied. If you enter combat with a 190 for example make sure you enter with good airspeed, try and have a height advantage if not at least be at the same alt. And when he climbs follow him maybe ease of throttle a bit as you get to same height but he will also dive to gain airspeed, that's when you need to get your speed back up so follow him down throttle up don't be afraid to use WEP I tend to use it then and the Mustang really goes downhill fast with WEP and you can get in nice and close. I can use it for short spells but not for to long and you do have to keep glancing down at your temp gauge. And I never use WEP in a sustained climb. :thumbup:

I Love DCS Mustang.

throttled back to 46 @3000

Maximum continuous is 46@2700. If you kept flying at 46@3000 continuously, it doesn't surprise me in the least that your engine died.

Maximum continuous is 46@2700. If you kept flying at 46@3000 continuously, it doesn't surprise me in the least that your engine died.

That's just a typing mistake. I am certain that David knows the setting for max continuous. He is a very good Mustang pilot.

as gavagai said, a typo sorry....

dont want to sound rude, so please dont get this wrong, but i dont need any dogfighting tips...against the AI i dont need no WEP whatsoever and shoot it down with flying only at max continuous without a problem...

i would like to have an official answer from Yo-Yo about a reliable way to use WEP and still being safe that the engine will go on...

:)

Maximum continuous is 46@2700. If you kept flying at 46@3000 continuously, it doesn't surprise me in the least that your engine died.

I think the OP is looking for a more detailed explanation as to the simulated effects of WEP within DCS... thus the "dear Yo-Yo" part.

We have many many documented tests of different scenarios involving engine settings and the finer details of WEP still remain a mystery. From what I've seen you can fly 61'/3000, despite what any literature suggests, pretty much all day as long as you keep your temps in check. WEP is a different animal altogether... I've detailed situations where I ran WEP at 67"/3000 on a warm day at low altitude for 30 minutes with no problem or indication of an issue and then the instant onset of an engine seizure occurred. I've also heard of people getting results from WEP in low turning fights even though the documentation says it offers no benefit below 5,000 feet.

I'm pretty sure the intent of this thread is a little beyond basic engine settings. Correct me if I am wrong, David.

EDIT: David beat me to it.

From what I've seen you can fly 61'/3000, despite what any literature suggests, pretty much all day as long as you keep your temps in check.

You can't. It will kill your engine, it just takes much, much longer.

I've also heard of people getting results from WEP in low turning fights even though the documentation says it offers no benefit below 5,000 feet.

This is somewhat strangely described in the manual. What it means is that even without going into WEP, the compressor provides enough MP to go way beyond 61inHg. I'm not sure whether the MP regulator behaviour is wrong or the manual, but there is of course no reason why the engine wouldn't perform better with 67inHg compared to 61inHg even at low altitudes.

You can't. It will kill your engine, it just takes much, much longer.

haha ok... I guess it's good I don't fly 6 hour sorties. My flight engineer, if I had one, would be very angry right now.

:)

 

I think the OP is looking for a more detailed explanation as to the simulated effects of WEP within DCS... thus the "dear Yo-Yo" part....

...

I'm pretty sure the intent of this thread is a little beyond basic engine settings. Correct me if I am wrong, David.

 

 

EDIT: David beat me to it.

no thats exactly what i want...

and btw, with full tanks(all three, no externals though) i can fly at 61@3000 until im out of fuel with no problem as long as the temps are in the ranges...

WEP, as Merlin said, has really strange outcomings...sometimes it seems you can fly half an hour with it(done that many times, with an boiling engine) even at low altitudes, and sometimes you will break the engine within seconds(although temps within range)....so i would like to hear official word from the guys who know how its simulated in DCS.

This is somewhat strangely described in the manual. What it means is that even without going into WEP, the compressor provides enough MP to go way beyond 61inHg. I'm not sure whether the MP regulator behaviour is wrong or the manual, but there is of course no reason why the engine wouldn't perform better with 67inHg compared to 61inHg even at low altitudes.

Sorry, I missed this part. And I agree about the "strange descriptions". I guess that is why this thread exists in the first place. Also, I may be misunderstanding what you said... from what I know about the P-51D, "breaking the wire" or WEP does exactly that. It takes advantage of that extra available power. The down side is that it imparts stresses on the Merlin internals beyond their rated limits.

AND to contradict the "no appreciable advantage" of using WEP at sea level view you can see a clear performance increase in the flight testing at Wright Field...if that document can be trusted. So who knows :)

Flight Test Engineering Branch

Wright Field, Dayton, Ohio

15 June 1945

Flight Tests on the North American

P-51D Airplane, AAF No. 44-15342

2. Maximum speed at sea level

War Emergency Power (3000 RPM and 67") 375 MPH

Military Power (3000 RPM and 61") 364 MPH

Normal Rated Power (2700 RPM and 46") 323 MPH

as gavagai said, a typo sorry....

dont want to sound rude, so please dont get this wrong, but i dont need any dogfighting tips...against the AI i dont need no WEP whatsoever and shoot it down with flying only at max continuous without a problem...

 

i would like to have an official answer from Yo-Yo about a reliable way to use WEP and still being safe that the engine will go on...

Please don't misunderstand Im not trying to give dogfighting tips I was referring to airspeed. My point was I can use WEP in combat or any form of flying and not blow my engine but if my speed drops to low and I use high throttle RPM or WEP the engine will die. I also was not sure if you have your radiator open? Without my Rad open again my engine can seize quickly.

The more stichometric mixture you force into the displacement chamber aka cylinder, the harder the BANG is, just as if you change the CAMS from normal cams to DRAG RACING CAMS.

It causes A: Heavy Pre-Ignition if the fuel is of LOW quality and if you cannot alter the "°" degrees of pre-ignition in your coil/blackbox

It causes B: bad mixture burn if you don't have enough VOLTS on your coils and spark-plugs

It causes C: general overheating that can only be partly compensated by water/methanol/nitromethane mixed into the fuel ( the vaporing of those components cool your internals, maybe enough..maybe not )

and finally: if your bearings, cam-shafts etc. are not fine balanced it will just ROCK YOUR ENGINE APART after so and so many minutes....

What it does in DCS I have no clue but this is what happens in RL if you squeeze in more mixture in than the engine is usually made for. Simple as that.

Bit

The more stichometric mixture you force into the displacement chamber aka cylinder, the harder the BANG is, just as if you change the CAMS from normal cams to DRAG RACING CAMS.

 

It causes A: Heavy Pre-Ignition if the fuel is of LOW quality and if you cannot alter the "°" degrees of pre-ignition in your coil/blackbox

It causes B: bad mixture burn if you don't have enough VOLTS on your coils and spark-plugs

It causes C: general overheating that can only be partly compensated by water/methanol/nitromethane mixed into the fuel ( the vaporing of those components cool your internals, maybe enough..maybe not )

and finally: if your bearings, cam-shafts etc. are not fine balanced it will just ROCK YOUR ENGINE APART after so and so many minutes....

 

What it does in DCS I have no clue but this is what happens in RL if you squeeze in more mixture in than the engine is usually made for. Simple as that.

 

Bit

Yup. But the standing question for Yo-Yo remains...

To what length does DCS simulate the effects of WEP on the Merlin engine.

thank you very very much Yo-Yo!!!

Very good to hear from your Majesty, Yo-yo. :) So the moral of the story: Take care not to push the engine too hard. She may get angry and ruin your day...sooner or later.

Anyone see shocking similarities between Yo-yo and Chuck Norris?

When Alexander Graham Bell invented the telephone he had 3 missed calls from Yo-Yo.

MP regulator set to cut MP cutting the power at the certain altitude, i.e. the power increases a little from SL th this altitude, then goes along the same curve. The more MP we cut the less is SL power and the higher is the knee or the critical altitude.

Thus, increasing the MP cut level we can only increase low level power, though the power at the altitudes higher than the knee remain the same.

Are you saying that the critical altitude for 61inHg is 5000ft?

THe engine will not give better performance HIGHER than 5000 ft! It is an obvious mistake in the manual.

The point is that if you have throttle full open all the way, the power will decrease as altitude increases.

 

MP regulator set to cut MP cutting the power at the certain altitude, i.e. the power increases a little from SL th this altitude, then goes along the same curve. The more MP we cut the less is SL power and the higher is the knee or the critical altitude.

Thus, increasing the MP cut level we can only increase low level power, though the power at the altitudes higher than the knee remain the same.

This might be a mixup between versions that did and did not have a MP regulator.

Hello,

some posts in this debate confused me. According to this report - Flight Tests on the North American P-51D Airplane, AAF No. 44-15342 (see below) - MP 67 InHg gives more power from AGL to approximatety altitude 13000Ft for 1st supercharge`s gear. I perhaps do not understand some facts, or I missed something.

Can someone explain it me in simple words? Thanks.

And, I have one question regarding MP regulator.

Is MP regulator simulated in game?

Two types of the MP regulator were on V-1650-7. Packard type on early and on late engines Simmond`s type. First was able to keep MP within 42-67 InHg up to the critical alt. Second was better and kept MP within 25-67 InHG, plus minus 1 InHg for both.

I set 46 InHg and 2600RPM after take off and climbed. MP started to decrease at altitude about 8000Ft. It is not the critical altitude for 1st gear.

Temperature was 15° C and ambient pressure was 760mmHg.

I thought that MP should be, for instance 45 InHg, from ground to the critical altitude (approx 16000 Ft) without moving throtle lever because of MP regulator which hold preset value.

Sorry for my bad English.

Thank You.

Ok, we already have one manual with erratic 15:1 glide ratio.... just another one? How can WEP THAT WORKS EXCLUSEVELY from SL to the CRYTICAL ALTITUDE affect engine performance above this altitude? Knowing that FULL THROTTLE operation is above this altitude?

 

By the way, go to wwiiaircraftoerformance please and take a look at the diagrams for climb ratio and maximal speed in comparison with 61-67-75 and more inches.

I think this manual (AAF Manual 51-127-5) just wants the pilots to use their engines more gently at low level. It's a training manual, not for test pilots. It is just a recommendation, not means engine will not get more power with WEP below 5000ft.

Using WEP is forbidden in training.

If you're extra bored or extra ambitious, read this.

http://www.enginehistory.org/Piston/Rolls-Royce/R-RmerlinABC/R-RmerlinABC.shtml