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migmadmarine

Trying to get the hang of the P-40E

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So, since it has been ages since I've tried to fly it, I've decided to have a go at a P-40 career. I know this is an aircraft a lot of people  feel is overly hamstrung by the modeling of engine limits as they stand (and I agree, I'd love to see the risk of damage become an exponential probability rather than a hard limit) but lets try to avoid getting into that argument again, and focus on how to work with it as it is. The thing I want to know right now is, which value, Prop RPM, or Manifold pressure leads to the engine damage? If I set my prop RPM to 3,000, but keep my manifold pressure below combat values, does the engine last past the 5 min limit? Or can I keep the RPM below 3,000 but run the MP higher without damage? Or must I maintain both of them below the listed settings to escape engine failure?

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Ok, I just ran an experiment, flying a quick mission autolevel on, with the RPM set to max but the MP under the cruse limit. The engine ran well past the five minute limit, so that seems to answer the core of my question. So it seems I have mostly been running afoul of the lack of an MP governor, and leading to engine damage that way by letting it creep too high in dives. 

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The difference should be visible in tech chat. As soon as the engine icon turns yellow or red, you're burning up some kind of limit. As long as the tech chat says you're flying at normal engine power, you're fine.

 

From what I've seen from other aircraft, it appears to be some combination of RPM and MP. It's possible that in some aircraft you can trade a bit lower MP for a bit higher RPM, or vice versa. That said, if you keep to the settings specified in the technical specs, you should be fine.

Edited by AEthelraedUnraed

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I fly with the tech chat off. And as I said in my second post, it seems that you can run max RPM for quite some time as long as your MP doesn't creep above the limit. 

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The nice thing about the P-40e is that the manifold pressure and rpm gauge both have safety limit markers on the dials.  I generally put the RPM gauge at just a hair's width below the little green marker on the dial.   I put the manifold pressure on the green line (below 40) for general purpose flight and gently bring it back to to lower green line before a strong dive.   The plane still gets to ~280mph in a cruise and has no problem in a gentle climb at the max-line that I use and rarely kicks over to combat power at the min-line in a dive.  

Keep in mind that the faster you go in a level cruise , the more the base-line manifold pressure increases so, you will want to make gentle adjustments to keep from going above 40MP as speed increases.   

 

IIRC, the radiator cover can be completely closed above 220mph.  Below 220mph, there is a marker on the radiator control lever that indicates "neutral" (30%).  There shouldn't be any need to pop the cover full-open unless the engine is damaged and simply won't cool down.   Ideally, the oil and water temps should be kept within the min/max green marker limits on their respective gauges.  I'm pretty sure it is modeled in-game that oil viscosity is dependent on temperature so keeping it at the right temperature range should help with engine life too.  (Too hot = to thin.  Too cold = too thick.)  Water running on the cool side of things shouldn't be too much of an issue but, running water too cold through a hot engine block could possibly contribute to the beginnings of micro-cracks in the engine block.  

 

This is for general cruising settings.  If you are in combat, you may find that you'll need to push the engine harder.  The best I can say about that is, the more opportunities you have to gain speed through gravity or if the current power setting still allows acceleration in moments of level flight - instead of pushing the engine - the better off you are.   Keeping optimal speeds and still having engine power in reserve is always a good thing.  

 

At least in single player, where fighting against similarly-performing AI planes is less brutal than multiplayer PvP, pushing into the combat timer for only a few seconds at a time and only when needed is quite feasible.  

 

 

 

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On 9/11/2020 at 3:12 AM, 69th_Mobile_BBQ said:

 

 

At least in single player, where fighting against similarly-performing AI planes is less brutal than multiplayer PvP, pushing into the combat timer for only a few seconds at a time and only when needed is quite feasible.  

 

 

 

 

I am still a little puzzled by this. If I have technochat on (so I can see what the game thinks I am doing) and slip into and out of high power settings does that 'eat' my 5 min limit at emergency power? Does the P-40 'recharge' like some others appear to do?

 

Otherwise the green marks on boost and RPM guages are normaly my guidelines - keep it a little below where possible but if above check carefully that one or the other is not been driven off the clock by speed / manouvring. Radiator I have open from t/o until c. 5,000 ft and cruising and then keep it shut unless the guages start to rise. Not flown it in MP, so what I have said may be insufficiently agressive.

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6 hours ago, EAF19_Marsh said:

 

I am still a little puzzled by this. If I have technochat on (so I can see what the game thinks I am doing) and slip into and out of high power settings does that 'eat' my 5 min limit at emergency power? Does the P-40 'recharge' like some others appear to do?

 

Otherwise the green marks on boost and RPM guages are normaly my guidelines - keep it a little below where possible but if above check carefully that one or the other is not been driven off the clock by speed / manouvring. Radiator I have open from t/o until c. 5,000 ft and cruising and then keep it shut unless the guages start to rise. Not flown it in MP, so what I have said may be insufficiently agressive.

 

I don't really understand the engine timer system either.  That's why I try to keep the P-40 engine out of combat power as much as I can. I figure If I need 10-20 seconds here-and-there for climbing power, or a few seconds of extra straight and level acceleration, or go over the line a few seconds in a dive, 5 minutes can be stretched a pretty long way.   I really have no idea if there's a "recharge" on the P-40 but, I'm going to guess the answer is "no".   

 

If I remember correctly, in-game planes that have a recharge were also able to run in RL above a certain temperature or stress level for a while, cooled-down and run hot again without damage. Or they have boost systems that need to be recharged after a certain amount of use - like the 109-K4, which can boost 3 times for 10 minutes each with a cool down required between each use.  IIRC the P-47 has a recharging cool down but, that's based on the temperature of the turbocharger and keeping it managed.  

I don't think the P-40 combat power falls into the category of being rechargeable but, I'm not sure.

 

As far as the radiator is concerned, I've never had to open the flap beyond the "neutral" mark on the radiator lever in the cockpit, and as long as I stay above 220mph, I can close it all the way. 

On a map with hot weather, I just make sure to check the temperatures more often and adjust accordingly.

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On 9/9/2020 at 6:53 PM, migmadmarine said:

So, since it has been ages since I've tried to fly it, I've decided to have a go at a P-40 career. I know this is an aircraft a lot of people  feel is overly hamstrung by the modeling of engine limits as they stand (and I agree, I'd love to see the risk of damage become an exponential probability rather than a hard limit) but lets try to avoid getting into that argument again, and focus on how to work with it as it is. The thing I want to know right now is, which value, Prop RPM, or Manifold pressure leads to the engine damage? If I set my prop RPM to 3,000, but keep my manifold pressure below combat values, does the engine last past the 5 min limit? Or can I keep the RPM below 3,000 but run the MP higher without damage? Or must I maintain both of them below the listed settings to escape engine failure?

 

That's a good question... and a I think that the engine damage it's not that square in the game. The engine performance change a lot acoording to the OAT, for example.... Oil / Water temperature increases or decreases according the the altitude too, so I don't manage the engine power in a way much different that I would in real life.

 

I never made this test in the game but probably the engine will not suffer a imediate damage running with 3.000RPM and a low MAP set... because the damage it's a result of a combination that will exceed a engine limitation.

 

A high RPM + Low MAP it is not good for the performance and will decrease the engine lifespan but will not result in a sudden catastrofic damage.

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