P47 turbosupercharger

[SCG_motoadve]

How is the turbosupercharger modelled in the P47?

Can we use it at full since take off , the whole flight, with no penalties at lower altitudes?

[RedKestrel]

1 hour ago, SCG_motoadve said:

How is the turbosupercharger modelled in the P47?

Can we use it at full since take off , the whole flight, with no penalties at lower altitudes?

I think using it when its not necessary does potentially cause minor speed loss. 

But keeping it at full forward does not result in any damage, turbo damming, or anything like that as far as I've seen. IAFAIK you can't damage it by improperly using it, other than if the RPM gets too high when you are above critical altitude.

[Barnacles]

1 hour ago, SCG_motoadve said:

How is the turbosupercharger modelled in the P47?

Can we use it at full since take off , the whole flight, with no penalties at lower altitudes?

At the same MP, it uses a bit of power to drive the TS, hence you can go faster without it. You can generally pull higher MP with it running though, even at sea level, so it's almost always just as fast, or faster to use it. Even at higher altitudes, the benefits of managing it 'properly' are negligible so in game you're best off just setting it to 100% , if you're not bothering with being historically accurate. I suppose it's the same way a lot of people just fly pe2s and yaks at 100%

Edited February 28, 2020 by 71st_AH_Barnacles

[Requiem]

Yeah, just keep the throttle and turbo linked until you climb high enough where you may need to manage the turbo separately to prevent overspeed. I don't have the manual on my phone but that's pretty much what it recommends. Micromanaging the turbo when you don't nees to just makes your job harder.

[LukeFF]

28 minutes ago, SYN_Requiem said:

Yeah, just keep the throttle and turbo linked until you climb high enough where you may need to manage the turbo separately to prevent overspeed. I don't have the manual on my phone but that's pretty much what it recommends. Micromanaging the turbo when you don't nees to just makes your job harder.

 

Yep, and it's interesting in that the very late P-47Ns dispensed with the separate lever for the turbo and just made it part of the throttle control.

[CountZero]

I always set it 100% at any time and no problem what so ever

[Lusekofte]

I micromanage it in climb. I seen no gain using it at 100% during climb I follow the instruments. 
but if I gain any  by micro managing it is not very clear to me. I do it because I have time

[rowdyb00t]

If anyone has 20 mins or so, this is quite interesting. 

[[=PzG=]-Southernbear]

To fly the P-47, and this is supported by the IL2 Youtube channel, Link both the turbo and Prop pitch to the throttle with "Left Shift+I" and "Left Alt+I" ...you don't need to unlink the turbo till your Turbo RPM gauge reads 22,000 (theres a big yellow line on the dial and the blinking red light will stay on continuously if your over speeding the turbo anyway) You never need to touch the Prop pitch again and once your high enough for the turbo to start over speeding (around 18,000 to 20,000 feet or about 5.5 to 6km) leave the throttle at 100 power and unlink the turbo. the Turbo control becomes your new throttle and above the critical altitude you use that to control your speed, not your throttle. As most engagements happen in IL-2 due to the game's tactical nature and having no heavy bombers to escort, Most engagements happen at about 4km and bellow so for the most part once you have the turbo link and prop pitch linked to the throttle on the ground before take off, thats the last time you'll need to touch them during the flight.

 

 

[Venturi]

The turbo is not parasitic unlike a sc, but it does rob exhaust gas pressure/thrust. 
 

If IL-2 were to model engines accurately, any throttle+turbo setting which gave you 100% allowed manifold pressure and no more, while retaining wide open throttle, would be the most efficient. 

Any throttle butterfly, when partially closed, induces by design a pressure drop behind it in the intake tract, which will need to be compensated for to achieve desired manifold pressure by increased turbo speed - and thus less exhaust thrust at altitudes above 1km or so.

 

Optimum efficiency is achieved with WOT above SC critical altitude, and manage turbo speed as necessary to achieve desired MAP. If we were in the real world. 

[ZachariasX]

1 hour ago, Venturi said:

If IL-2 were to model engines accurately, any throttle+turbo setting which gave you 100% allowed manifold pressure and no more, while retaining wide open throttle, would be the most efficient. 

This is actually what the „automated“ throttle does in the P-38 and I would guess in the later P-47 as well. As you advance the throttle lever, first it opens the butterfly and once this is full open it starts directing exhaust gas to the turbo.

 

The linkage is only useful as working the butterfly gives you more immediate response than working the turbo while it keeps the turbo in a somewhat sane setting. For our game, it caters those with only one throttle lever.

 

It is not really the engine in terms of power/performance that supposedly is not modeled correctly, it is that on our „maps“ mileage is no issue.