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Seeming lack of power despite instrument indications


SMH

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Had this happen a few times seemingly randomly when flying online, but it seems it can be reproduced reliably by flying the P-47: Instant Action: Caucasus: Cold Start mission.

 

After starting and waiting for oil pressure to normalize, full throttle and boost are applied for takeoff roll. It barely gets airborne before the end of the runway, then won't gain airspeed or climb despite flaps and gear both being up and all power and RPM indications showing max power.

 

Oddly, when I get dirty to try to land again, that's when it seems to pick up some energy, causing me to overshoot the first landing attempt. But as soon as I raise gear and flaps it's back to barely having enough power to stay in the air.

 

This doesn't happen all the time, only sometimes. But so far that particular mission seems to cause it every time.

 

Track file attached.

P-47_Weak_CaucasusColdStart_01.trk

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First tip - don't bother with warming up and waiting so long for the oil temp and pressure to normalize. They'll magically do so immediately after appllying takeoff power. Makes flight testing faster (until proper temp modelling is implemented) ;).

 

Second - does it happen as well if you set oil and intercooler shutters as per manual (neutral or closed), and not wide open as you did? I haven't experienced such a behaviour myself, but I've alwasy flown with intercooler shutters at neutral. Maybe their drag is calculated incorrectly.

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

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I watched your track.

1st engine power is very low indeed during take off run engine cant reach 2700 rpm.

2nd you over heated engine in warm up 260 C is max you hit 300 C.

I noticed that engine headers temp was rising very slow.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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Looks like sparkplug fouling. You are waiting a long time at low rpm.

 

When I takeover the flight and skip the warmup, the engine is fine.

As Art-J said. Currently not necessary to warm up the engine.

Warm up is not correct and no engine damage from not warming her up.

 

 

Fox

Spoiler

PC Specs: Ryzen 9 5900X, 3080ti, 64GB RAM, Oculus Quest 3

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I just did full warm up, in this instant action mission at 900 rpm -1000 rpm no problem

Only difference i can see is that on my end, cylinder head went above 200 C with cowl flaps open pretty quick, while in his case temp stopped at 150 C no idea why.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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I don't see how it can indicate those RPM without having the power that should be associated with it.

 

And oil and intercooler open are per the real manual. Though I see now DCS's manual recommends the neutral position. I'll try that.

 

Also, the only time I tried taking off without waiting for oil pressure to normalize, I had weird surging of the turbo. (Not sure why those two systems would be related. The engine and turbo have different oil systems, I believe.)

 

Can anyone else reproduce this on the Caucasus: Cold Start mission?

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What are your game settings ??

Full realism or Arcade ?? Like flight mode , unlimited ammo or fuel etc ??

And i noticed that you instantly switched magneto to Both position try switch is through L and R then Both.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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What are your game settings ??

Full realism or Arcade ?? Like flight mode , unlimited ammo or fuel etc ??

And i noticed that you instantly switched magneto to Both position try switch is through L and R then Both.

 

Realism. I don't use that baby stuff.

 

(And I am not aware of any DCS plane that models the difference between the two magneto banks. We don't see the RPM drop we should when switching to a single bank in any plane. Anyway, both is the proper procedure for startup.)

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Realism. I don't use that baby stuff.

 

(And I am not aware of any DCS plane that models the difference between the two magneto banks. We don't see the RPM drop we should when switching to a single bank in any plane. Anyway, both is the proper procedure for startup.)

 

I know, but the sequence is important, sometimes DCS gets crazy when something is switched in unnatural manner.

I've seen this with trim wheels, another stuff.

Just switch it by mouse.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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I know, but the sequence is important, sometimes DCS gets crazy when something is switched in unnatural manner.

I've seen this with trim wheels, another stuff.

Just switch it by mouse.

 

I did.

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I tried to reproduce in that cold start mission: without waiting, with waiting (time acceleration), shutters neutral, shutters open, game flight mode, sim flight mode, you name it. Never had issue with reaching 55-58" of MAP.

 

One thing worth noting in your replay, though, is mysterious banging coming from the back of the airplane with full throttle setting.

i7 9700K @ stock speed, single GTX1070, 32 gigs of RAM, TH Warthog, MFG Crosswind, Win10.

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I tried to reproduce in that cold start mission: without waiting, with waiting (time acceleration), shutters neutral, shutters open, game flight mode, sim flight mode, you name it. Never had issue with reaching 55-58" of MAP.

 

One thing worth noting in your replay, though, is mysterious banging coming from the back of the airplane with full throttle setting.

 

It's not the MP or RPM that are low. Just my airspeed and climb rate. It's like there's phantom drag. It also seems to improve when I lower the gear and flaps to try to land. Suddenly I start *gaining* speed! Almost like the drag effect of raising the flaps and/or gear gets reversed somehow.

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It's not the MP or RPM that are low. Just my airspeed and climb rate. It's like there's phantom drag. It also seems to improve when I lower the gear and flaps to try to land. Suddenly I start *gaining* speed! Almost like the drag effect of raising the flaps and/or gear gets reversed somehow.

 

In your replay RPM are definitely too low on the ground when you are doing take off roll engine cant reach 2700 rpm. this indicates very low power, looks like you are trying to take off with 25-30 inch.

My replay is different from beginning, your engine head temp is way too low, mine hits 200 C very fast, your could not pass 150 C still after long time.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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It wasn't that low when I recorded it.

 

I recorded video of the original flight too but unfortunately I just deleted it as it seemed the track was sufficient.

 

I watched your track, it was low. much lower then on my end.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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Overheating the engine doesn't really affect it right now. You can cruise around with 300C without problems

 

They really need to improve on that it's embarrassing, even FSX 10yr old sim has modules with proper oil, heating simulation.

[sIGPIC][/sIGPIC]

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They really need to improve on that it's embarrassing, even FSX 10yr old sim has modules with proper oil, heating simulation.

 

It is only like this, because it is not here yet, Early Access etc etc.

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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I don't see how it can indicate those RPM without having the power that should be associated with it.

 

And oil and intercooler open are per the real manual. Though I see now DCS's manual recommends the neutral position. I'll try that.

 

Also, the only time I tried taking off without waiting for oil pressure to normalize, I had weird surging of the turbo. (Not sure why those two systems would be related. The engine and turbo have different oil systems, I believe.)

 

Can anyone else reproduce this on the Caucasus: Cold Start mission?

 

RPM AND MP are a power indicator. RPM alone isn't.

 

With your replay I can reproduce it. If I take over the flight before the waiting at the runway, the engine is fine.

 

That turbo-surging was probably caused by the not closed/locked primer handpump.

 

No oil temperature/pressure in the P-47 has any influence on the engine at the current state.

You can keep every cowling closed at full power till your fueltank runs dry. It's the same with the Anton and the Yak. No engine damagemodel. Sparkfouling is modeled.

 

It is only like this, because it is not here yet, Early Access etc etc.

No Spee. Anton isn't EA anymore, yet still no engine damage at all.

 

Fox

Spoiler

PC Specs: Ryzen 9 5900X, 3080ti, 64GB RAM, Oculus Quest 3

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That turbo-surging was probably caused by the not closed/locked primer handpump.

 

I would hope not. That makes no sense.

 

Or... what... the engine is becoming fuel starved when the turbo is operating? It didn't feel like that. It felt like it was the turbo surging the engine, not the other way around. Will see if I can reproduce it and get a track.

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No Spee. Anton isn't EA anymore, yet still no engine damage at all.

 

Fox

 

It is coming because ED stated that for full engine DM we need to wait for P-47 being fully developed.

I did full warm up of the engine, in this mission with no problems.


Edited by grafspee

System specs: I7 14700KF, Gigabyte Z690 Aorus Elite, 64GB DDR4 3600MHz, Gigabyte RTX 4090,Win 11, 48" OLED LG TV + 42" LG LED monitor

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