MW 50 always on?

[NineLine]

I havent overboosted my engine, or rather run the MW50 tank dry yet, is there currently no consequences to that in the sim? If so it would be a bug.

[sobek]

Definately, the P-51 e.g. should feature overboosting. If running low RPM and high boost doesn't kill it, then that is a bug.

[Flying-Kane]

Nice thread, and here's my question... :D

 

But what's with the K-4, when we can choose between additional fuel instead of MW50 (maybe in the future).

 

The engine should be restricted to provide only 1,42ata as Start- und Notleistung. The high boost pressure (1,8ata) was only in cooperation with MW50 or did i miss something?

 

Kane

[Flagrum]

Well the ata gauge shows manifold pressure, and manifold pressure is not dependant on MW50. The compressor can still provide boost just fine, it's just that the rest of the engine doesn't like it all that much.

But this is different in the 190 - when at 100% throttle and you switch on the MW50 injection, you notice a sudden boost from (iirc) 1.6 to 1.7 ata.

 

Or is this just the Motorbediengerät that is responsible for that?

[sobek]

Or is this just the Motorbediengerät that is responsible for that?

 

I would assume that that is the case but it's a long time since i read the documentation for the MBG.

[shagrat]

Ok, I just spent a good 45 minutes in the Bf-109 K4 testing a bit. (current Open.beta 1.2.16)

 

1. the ATA increase from 1.45 to 1.85 at full throttle has a noticable and audible effect. It does so with or without the MW50 enabled, as is to be expected, as MW50 is not boosting itself, but enhancing the effect of the compressor boost by reducing heat and preventing premature ignition of the mixture.

 

2. I flew with MW50 disabled at max throttle, with 1.85 ATA for about 40 minutes. Oil temperatures never increased beyond 115°C and no damage to the engine was noticable.

I would have expected at least an increase in Oil temperature beyond 120° into regions where the viscosity is changing and engine seizure is likely to happen.

 

Neither did any "knocking" or other indication of premature ignition show.

 

I flew all maneuvers at full throttle, below 3000m.

 

Finally, in a desperate try to damage the engine, I switched the Tank selector to FUEL so the MW50 should have been pumped into engine fuel system, rather than the mixture chamber... After 5 min there was still no noticable negative effect.

 

I'm no subject matter expert, but it looks like either engine damage is currently not finally modeled, or it is bugged.

 

Or is the DB605 engine THAT resilient?

[Siegfried]

When I have MW50 and change MW50/krafstoff to fuel mode, in 4 minutes the engine stops. I think that MW50 mix with fuel in tank and gasoline is contaminated with methanol and water.

 

I had testing this just now. 1.2.16 with fridays patch and previous versions too.

[Flying-Kane]

Ok, I just spent a good 45 minutes in the Bf-109 K4 testing a bit. (current Open.beta 1.2.16)

 

1. the ATA increase from 1.45 to 1.85 at full throttle has a noticable and audible effect. It does so with or without the MW50 enabled, as is to be expected, as MW50 is not boosting itself, but enhancing the effect of the compressor boost by reducing heat and preventing premature ignition of the mixture.

 

2. I flew with MW50 disabled at max throttle, with 1.85 ATA for about 40 minutes. Oil temperatures never increased beyond 115°C and no damage to the engine was noticable.

I would have expected at least an increase in Oil temperature beyond 120° into regions where the viscosity is changing and engine seizure is likely to happen.

 

Neither did any "knocking" or other indication of premature ignition show.

 

I flew all maneuvers at full throttle, below 3000m.

 

Finally, in a desperate try to damage the engine, I switched the Tank selector to FUEL so the MW50 should have been pumped into engine fuel system, rather than the mixture chamber... After 5 min there was still no noticable negative effect.

 

I'm no subject matter expert, but it looks like either engine damage is currently not finally modeled, or it is bugged.

 

Or is the DB605 engine THAT resilient?

 

40 min without damage? :huh: There is definitely something wrong.

 

Using "Sondernotleistung" (1,8ata) without MW50 was forbidden.

[NineLine]

The aircraft is still in beta, put I will point Yo-Yo to this post to make sure we arent over looking something...

[shagrat]

The aircraft is still in beta, put I will point Yo-Yo to this post to make sure we arent over looking something...

 

I consider some more guys try and test this. Seeing Siegfried had an engine seizure after 4 minutes with MW50/Fuel switched, we should check if this was just my lucky day.

 

At least Yo-Yo could provide some estimates, how long the sim tolerates / should tolerate running on full boost 1.85 ATA without MW50... Manual and documents may say it was forbidden, but knowing german engineers, I wouldn't be surprised if it can take quite a beating.

 

Still at least engine temperature should start raising after some minute or two latest and we should have problems with lubrication failing at 120-130°C latest, right? :D

[Siegfried]

Three times consecutives I tested and three times my engine stops at 4 minutes. Always that I try this, I get engine stops.

 

In mission editor select MW50 and start in the air at 2000 meters for example.

 

Select kraftstoff in cockpit and set the engine 1.4 ata 2500rpm. Rpms auto and mw50 sistem is on but never go to full power. Anyway if select kraftstoff and go to full power, the MW50 pressure don't raise.

 

4 minutes later the engine stops but keeps windmill, not seizure.

 

Other details I noted when motor stops by MW50 contamination.

 

If I go climb untl the propeller stops, when dive at 500km/h it don't start to windmill again. Pitch 11:30-12:30 o'clock.

 

If I dive after engine stops, set the propeler pitch at 12:30, the engine seizure at more of 3500rpm. How expected.

Edited March 16, 2015 by Siegfried

[Siegfried]

More testing.

 

Go at 1.78ata full throttle with MW50 on and running and then select kraftstoff and the MW50 pressure gauge drop to zero. Start to time counting the engine stops at 2.5 minutes aprox. Half time that at 1.4ata.

 

If I go at 1.1 ata 1900rpm the stops reach at 4 minutes.

 

I observed that the fuel pressure gauge don't drop when engine stops. I try flight inverted after the engine fail due a MW50 contamination and the fuel pressure drops in 4 seconds. When I fly leveled again, the fuel pressure rise again. Engine windmilling moving the fuel pumps I guess. This seems simulate the fuel system run but the fuel is bad quality by MW50 contamination.

 

Another test is with B4 in rear tank, I can fly indefinitely without troubles with MW50 selected and the system activated at full throttle 1.78ata. But when you have B4 in rear tank, the MW50 system pressure don't rise. I think that the airplane don't know what fluid the tank have and should inject B4 at compressor. This event should trigger bad things at engine?

 

Another thing, I don't know if the engine uses the fuel in rear tank when you have B4 and select kraftstoff. The fuel gauge seems move soon.

Edited March 16, 2015 by Siegfried

[NineLine]

Just heard from Yo-Yo, and the damage from running it dry are not yet modeled. So WIP.

Edited March 16, 2015 by NineLine

[silentconvo]

Thanks for finding that out. Could you please let ED know the current manual doesn't seem to clearly state that it is not permitted to run the engine at 1.8 ata without the MW50?