grafspee
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Posts posted by grafspee
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10 hours ago, Nealius said:
I have a suspicion that if I reverse the flow by turning off mags first then pulling the cutouts, it may work as intended.
That would be incorrect order because engine has to shut down due to fuel starvation not by lack of ignition.
So by shutting down fuel by fuel selectors is way closer then shutting engine via cutting off magnetos. I wish that ED would implement punishment for shutting down engines via magnetos by immediate fire of engine compartment, because when you cut magnetos and fuel is still introduced to inlet, hot fuel air mixture will come out of exhaust causing serious fire risk and on top of that those pressure carbs induce fuel even when engine is not rotating, so when engine stops fuel will pour out of engine inlet on the ground making small fuel puddle in quite short time.
I just tested it and even when i cut off fuel via fuel tank selectors engines still get tis splutter at the lower rpm. Just same story perfect rpm run down to about 200rpm and then engines wakes up splatter loop with rpm spikes.
So at that moment switching magnetos off is probably only way to avoid this splatter loop.
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16 minutes ago, Nealius said:
So according to the pilot's notes:
800rpm, pull cutouts, wait for prop to stop spinning, shut off magnetos. So I did. Right engine took 33 seconds to stop spinning after pulling the cutout.
On the left engine, I decided to shut the mags off early to see what happens. Left engine stopped 4 seconds after shutting off mags, skipping the 33 seconds of sputtering.
This is so ridiculous. It makes me sick by watching this.
I advice to cut fuel via tank selectors next to cut outs. This way you should avoid this engine splutter but engine will still keep running quite long before cuts out. Running engines up to 1500rpm will speed things up.
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9 hours ago, Skewgear said:
For those saying the engines should splutter and backfire a bit on shutdown, it seems the real aircraft shuts down very quickly indeed with barely a pop:
This is exactly my point, if any splutter or backfiring happen it will happen while engine still has high rpm. Like on this recording, not at moment when engine is about to stop rotating.
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4 hours ago, Art-J said:
Now, thinking about the Merlin engine itself, one could argue that fuel is being cut off at pressure carb level and thus there's still unspecified some of the mixture left in manifold between carb and intake valves.
This is why always say that, engine should not cut out at moment when you move mixture to cut off, engine should run for some time, and after noticeable delay engine should cut out and if any spontaneous fuel induction happen there is a time engine to splutter when rpm is quite high so that spark from magnetos is strong. In DCS we have instant reaction on cut off lever and perfect engine rpm run down to 100rpm and then magic happen. I wonder why in those planes you have something like boosters coil when engine without priming and coil boosting combust fuel without problem
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@Art-J I won't hold my breath for full fidelity start ups and shut downs but ED could at least remove this splattering loop at 100rpm. This is my main issue and main issue of this topic.
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@Art-J I agree, this splatter sounds and acts like this during start up with primer.
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Just for sake of realism i just shut fuel, engines are running much longer after shut off but they won't enter this splatter loop at low rpm where engine is about to stop.
@Slippa I would love to but i live in Poland, reason why i've been in UK was different then visiting museum. Maybe some day it will happen
If i would live in UK i would not miss a single air show unless 2 or more would happen at the same time 
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This issue was brought long time ago on this forum.
This backfire script is present in spitfire p-51 and mosquito because all of them uses same code, could be in P-47 as well but i can't remember.
Shutting via cutouts not by magnetos off is that engine burns out all remaining fuel from carbs it prevents fuel leaking in to inlet or outside of the plane.
This is how this should work.
1 Run up engine to 1200-1500 rpm P-51 manual states it should be 1500rpm
2 Move cutoff lever or mixture lever to cutoff position
3. After lever is moved engine still runs because remaining fuel in fuel system is still distributed to inlet
4. After short period of time engine dies and prop quickly stops rotating if cut out is set in wrong way you may be not able to shut down engine or prop will come to stop after longer time, but if cut out allow to some fuel be distributed to engine it will not magickly stop firing and re-ignite at 100rpm, it will splutter through whole range of rpm.
I had opportunity to visit Duxford air museum this year and in proces of exploring it, at least 3 or 4 spitfires started to take off, do fly by and some aerobatics like loops, so i ended up watching those Spitfires for at least 3-4 hours. I've seen couple start ups and shut downs as well as run ups.
And i say that non of them act like DCS one.
In DCS when you move this cut out lever engine shuts down immediately and when engine is about to stop it splatter again over and over you can see it on tachometer needle bouncing like a ball bouncing of the floor.
My conclusion is that nether start up and shut down works correctly in DCS.
Start ups are way to clean, throttle response with cold engine is way off, engine run immediately smooth as butter which for person who saw at least on start up knows that this is not true.
Have you encounter any unsuccessful start up beside those in which you forget to turn on fuel or mags on ?
And shut downs are off to, mainly because engines react instantly at cutoff lever movement and whole range from 1500 to 100 rpm doesn't splatter even once and when it is about to stop suddenly fuel is introduced to engine inlet sparking sporadic combustion. At 100rpm engine barely catch up when primer is used so why it should catch up when spark from magnetos are almost non existent due to that coil booster is off and some fumes of fuel magically ignites at 100rpm. This is ridiculous.
This recording is the most interesting, we can hear idling spitfire up close and second spitfire is taking off, how i could hear that was exactly same way as on this recording, as soon far spitfire firewall throttle sound of the engine/prop overwhelmed everything else.
If someone ask, yes spitfire sounds exactly like as on this recording from smartphone difference is only in how loud is that. Smartphone's software lowers microphone sensitivity when louder sound comes in, so idling and taking off spitfire loudness looks the same but it isn't, taking off spitfire is much much louder, this is why in DCS idling warbirds sounds so quiet.
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It is just a simulation, it could be that starter is missing code responsible for battery drain. Also ambient temp should impact how fast starter will rotate engine,at lower temps due to lover battery efficiency and higher friction inside engine.
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On 11/17/2023 at 7:47 PM, Tree_Beard said:
I often hear the P47 described as a superb high-altitude fighter.
I must be missing something, because if I launch a mission with a high-altitude air start, the plane feels like a boat drifting to the left and right and honestly feels terrible to fly, sluggish and hard to control.
Is there something wrong with the air start settings? Maybe something wrong with my hotas axis or something?
I always exit the mission with the impression that that just didn't feel right. I am still a P47 noob though so I'm not sure if there actually is a problem here or not. The other warbird I have is the BF109, and that feels waaaay better to me, even at high altitude, where the P47 supposedly shines.
K-4 is very stable in pitch and responsiveness is way lower then in P-47, at low alt at high speed K-4 will struggle to pull +6G but at high alt pitch responsiveness is at good spot, in P-47 you have no problem to pull +8G at high IAS but at high alt where IAS is low you need extra care when applying pitch it is very easy to stall.
Second thing K-4 improvement at high alt performance is very large comparing to earlier like G-6s. So P-47D vs K-4 combat is not as easy as you may thought, but still doable.
K-4 production numbers were very low comparing to overall Bf-109 numbers so chances that allied pilot encounter K-4 were very slim.
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It looks like tail wheel is jumping
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@SharpeXB If you dogfighting and you are following plane while he is pulling 2-3-4-5 G you are experiencing WT equivalent to plane which weigh is 2-3-4-5 heavier then you, so trick it to not enter his WT by flying above him or with side offset, if you stay dead center behind expect rough ride.
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21 hours ago, jackd said:
Thanks all, guess i must live with riding a DCS p51 ..
You can lower saturation, it will transform stick movement to shorter elevator range. In those planes elevator movement range is much larger then it is used in flying.
Only cone from this will be shorten max deflection of elevator which in case of elevator damage may lead to lost control over plane.
Anyway if you complain about P-51 you should try Spitfire
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2 hours ago, EnvyC said:
False, German records show it was a factory standard fitting by July 1944 and the majority of existing airframes were field modded.
Even if all antons by 1944 had increased ratings, this does not change fact that ED isn't planning adding this in near future. At least i haven't seen any news or statement from ED about it.
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7 hours ago, MAD-MM said:
The later Models of D9 1900 Ps Take Off Power often described with continious Power setting of 3000 RPM . Emergency Power 3250 RPM is described with 30 Min. But thats from flight testing reports no official engine manual. After the 109 Report the heat dissiapted from engine is the same with/without MW50 will not matter for cooling at least. The mechanical wear of course will increase.
In DCS we don't care about engine life time in terms of total work hours before engines replacement, so data from flight testing is more then enough, if they could test D9 at 3250rpm for 30min and they established continuous power at 3000rpm i'm good with that. Modeling DCS D9 that way, that we could not follow those tests with success is even more bad, then not knowing factory limitations.
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1 hour ago, saburo_cz said:
The "increased take-off power" is name for 1,7ATA (1900hp) engine power setting in German documents - Erhöte Notleistug.
Power with MW is "special emergency power" - Sonder Notleistug or Sonder Notleistug mit Methanol.
In the end, the 3 min limit isn't just error in dcs manual, as often.
Still looks like error in DCS manual because 1,7ata isn't achieved at full throttle like DCS manual states. And in DCS Dora we can't go 1.7ata since w/o mw50 we get 1.56ata if i not mistaken and 1.9ata with mw50.
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Ofc provided that manual is true, 3 min limit corresponds to emergency power or increased take-off power which will be 3250rpm and MW50 engaged.
3250rpm w/o MW50 will correspond to take off, combat and climb power with 30min limit.
If we look at fuel consumption column it becomes clear that those 3 min and 30 min apply for different engine powers but throttle position is the same so only mw50 on/off is difference.
I'm just reading DCS's manual exactly as it is.
So i do not agree that 3 min limit apply to 3250 rpm with or with out mw 50, manual states other wise, if manual is wrong than it would be good to correct it.
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@Hobel Even above 6k m mw50 increase engine power. Remember that you are running engine at max power so cooling issues may happen depend on situation. What needs to be checked, are cowl flaps wide open when overheat happens. Is automatic system capable to open cawl flaps fully.
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On 5/27/2023 at 12:04 PM, cw4ogden said:
@Hobel
My apologies to you both, I was able to reproduce the bug. Sorry for being skeptical, but in the video it looks like engine mismanagement.
My conditions were about 30 minutes into a mission, both temperatures around 100-110C, level flight. I engaged MW50, needle moves, started a clock figuring I had at least 3 to 10 minutes before anything would start to overheat. Engine made a sound I've never heard, loss of power followed by and subsequent total seizing of the engine. I'd guess it occurred within 30 to 40 seconds of what I'd consider "proper" mw50 use.
No useable track file as I was 30 minutes into the mission.According to DCS manual with mw50 and 3250rpm time limit is 3 min.
30min time limit is for 3250 rpm but w/o mw50
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26 minutes ago, Hobel said:
And what is the limit below 7500m?
Is 30min for 3250rpm lvl flight below 7500m correct or not?
This is what @NineLine linked earlier.
This refers only to Cruise, doing combat there is no single reason in DCS manual to not use 3250 in climb or in combat.
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45 minutes ago, Doughguy said:
Hm.. i usually climb with 3000 after i reach 300kph upon start and climb to 6k with said settings.
Once im at said alt i throttle back to about 2800, and on egress to 2500 depending on fuel etc.
But yea for combat i also push it to 3250 but not all the time but i rarely fly her above 6k. shes quite a fuel guzzler.
Proper climb procedure from DCS Dora manual
If you climb at 3000 rpm you are below climb power level so you are not abusing engine.
I don't buy claims that not climbing Dora with climb power which is 3250 rpm is engine abuse at all since climbing at 3250 with 280-290 kph is way more abusive then flying at same power at higher speed due to much better cooling. As long as you not running engine +30min at 3250rpm no engines will be harmed.
If someone wonder, i assume that that 3min limitation if for 3250rpm + mw50.
Ofc if DCS manual tells the truth about sim model.
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6 minutes ago, Hobel said:
Oka I am confused.3000 rpm continuous power is clear.
Max 30min 3250 rpm only over 7500m?
And under 7500m what is the highest rpm web limit?
i thought 30min 3250rpm should also apply below 7500m?If it doesn't then what is max rpm limit below 7500m?
It is easy max continuous up to 7500 is 3000rpm above 3250rpm. 30 min limit for 3250rpm below 7500m, above no limit
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24 minutes ago, NineLine said:
No and as I said the point I am at in the track temps look mostly ok, but it's still outside recommended procedures.
No, Manual do not match what we have in game or No, 3250 is not climb power, or No using 3250 for less then 30min for not climbing will damage engine. I'm not sure where this "no" fits is it answer to all what i said or to one particular thing.
Engine stops during start-up process
in DCS: Mosquito FB VI
Posted · Edited by grafspee
If you have switches mapped to your hotas it may be a case that you turn off fuel or pulling cut outs by mistake especially if you have this checked ON