grafspee

Even for models 25 through 35 you have take off stop which mean that 52" is achieved not at 100% throttle movement like it is in P-51. But still it does not provide any proof of having automatic boost control like in P-51. And as you can see in this manual power chart shows that P-47 is capable of making 52" at 34k of alt. I can tell that you can over boost P-47 even without turbo, you just need enough ram air to do it and you can get +52" on supercharger only. There are planes with take off stop and there are with out it why so i don't know. And turbo regulator job is to maintain set boost level but reference is not boost pressure but exhaust back pressure and this makes regulator imperfect which require during climb to retard boost lever and from some point to maintain boost pilot has to advance boost lever. This boost regulator does not governs turbo rpm so pilot has to monitor torbo rpm.

@Wizard_03 You can not have automatic boost control while having throttle and boost lever as separate levers. https://www.enginehistory.org/Turbochargers/TSCtrlSys/TSCtrlSys1.shtml In P-47D only automatic regulator was turbosupercharger regulator but this regulator used only exhausts back pressure as reference so pilot had to constantly adjust boost lever to maintain boost this already exclude regulator like in P-51 or Spitfire where you can set power and automatic regulator will take care but not in P-47 Proper automatic boost regulator was introduced in P-47N-25 and there you have single throttle lever and automatic boost regulator which takes care of turbosupercharger and supercharger boost. So once again no P-51 like boost regulator in P-47D You have manually controlled throttle valve at supercharger inlet and automatic supercharger regulator which maintains set back pressure. And none of those will prevent from over boost, does not matter if this over boost comes from turbosupercharger or RAM air.

@Wizard_03 So what max boost should be governed by this boost regulator ? 52" or 64" ? This is form P-47N manual and starting with P-47N-25 automatic engine control showed up but this one only control throttle valve and turbo waste gate to operate in best efficiency but still over boost could happen if you push throttle too far. P-38 was plane from different company as well any other so this is no near proof that P-47 had ever automatic boost control. P-47 D manual. This should answer your question, P-47 did not have boost control like in P-51 or spitfire, if you pushed throttle and boost too far you will over boost. So this mean that all other sims failed to deliver proper engine model That is why i always choose DCS.

For supercharged engines they did, but for turbo supercharged they did not.

Proper automatic boost control showed in P-47N but in early version you have only boost control for turbo supercharger but this unit governs exhaust back pressure.(constant back pressure does not provide constant boost and does not provide max permissible boost govern) P-47D is missing not only automatic boost control but engine cooling/ oil and intercooling shutters are operated manually, it is obvious that designers haven't focused on automation but on solving turbo supercharging single engine fighter. There was many attempts to create turbo supercharging fighter but only republic P-47 succeed.

If real P-47 haven't one, why DCS P-47 should have ?

It is as said above. At max rpm 2700 supercharger draw about 300hp from engine and supercharger compression is the same at certain rpm. If you open throttle max w/o turbo and you obtain 45" MP you are using all your supercharger which sucks 300HP and in case when you open throttle and turbo boost, since turbocharger make initial boost so it does some work for supercharger but supercharger constant speed will boost even more so you have to throttle down supercharger inlet to level which at the supercharger output gives 45" and this reduce power of the engine due to couple factors, 1. Increased inlet air temp which makes air less dense, air charger less dense = less power at the same boost a. Throttle only situation 45" Turbocharger inlet 30" -> Turbocharger outlet 30" -> throttle inlet 30" -> throttle outlet 30" (at this point air is not heated up) -> supercharger inlet 30" -> supercharger outlet 45" (air charge temp increased). b. Throttle and turbocharger Turbocharger inlet 30" -> Turbocharger outlet 45" (air charger temp increased) -> throttle inlet 45" -> throttle outlet 30" (at this point air charger is heated by first charging stage ) -> supercharger inlet 30" -> supercharger outlet 45" (at this point air charge is heated by factor 2 by first and second charging stage). I ignored ram air in this flow. 2. Increased back pressure which draws power down

@jackd Yes this is the setting which i had in mind, i just couldn't recall exact setting name, sorry about that confusion.

This option can only be accessed from main menu, can't remember which tab is it, but it should be in third tab after system. https://images.app.goo.gl/jy8oKfUBk9NJvgrSA

If you don't want to have this you can switch off controller sync in option, that way game when reload or reslot will not sync switches and axis with your controllers unless you move axis or press switch. That way if you start hot engine will not shut off in case when at your controllers engine was shut off, same with throttle which you advance fully after engine shut off, at hot restart throttle in game will be retarded despite the controller throttle is full on.

I can only imagine how much text and other stuff you have to go through.

15 story building that 37mm is wicked. Looks more like 16" naval gun impact

Agreed.

@Gunfreak I must remind that Kurfurst flight model burns up numerous heated discussions so it isn't good example Maybe they don't want to made same mistake.

I know that, i was talking about complete set for BoB in DCS terms so at least 1 flyable fighter for each side, couple bombers and attack AI planes and map.

If anyone thinks that ED intention was to build coherent theater (Map + period + planes), i must shock you but it was never goal for ED. And effects of this we can see. @stuart666 You are completely right despite the fact that F6F hellcat is awsome plane and i would love to fly it in DCS, but it will add another 2 years before we see complete Battle of Britain planes set and map of proper period. And right now ED is focused on something else because i haven't seen any news about ww2 development for long time, i may be missing out something so i apologize if it is not true.

If you watch hole thing you will see couple hvars launches and impacts. Those explosions looks more like light mortar rounds impacts. https://youtu.be/SAPqr3YCNmA?si=qbnNTrmMQD68IXP9

Only visual effects looks large but lethal explosion radius is very small.

Unfortunately fixing prop governor still won't solve 3060 rpm dive limit which can be used in case prop governor loss due to battle damage and if engine revs up above 2800 rpm at that moment engine is lost which is not true.

P47 was tested in dives at 15' and 2550 rpm and glides with power off. Engine used with care will score more hours but immediate engine failure during permissible engine over speed is not right.

Manual states that during loss of elevator control in high speed dive throttle can't be pulled all way back because it will steep dive even more. But last time i checked in DCS P-47 does not experience compresibility elevator loss of authority this not apply to DCS P47. Even if you start dive from split-s which is also forbidden in manual above certain alt. High speed dive happens when plane mach number is above 0.7 so diving from 10k ft you are completely safe. Elevator control comes back usually at 17k ft of alt. P38 was the plane which brought real pain because this one at 30k power on and 15 degree dive was entering compressibility elevator authority control loss and horizontal stabilizer loss of efficiency. That resulted in immediately dropping nose and entering lethal dive in wich pilot should do all things to not accelerate plane beyond structure integrity speed limit, unfortunately many died. P38 enters compresibility at mach 0.65 or so, very early comparing to P-47, at first trial tests they were afraid that P47 will be another P38 but compresibility in P47 turned out to be much mildly. Dive recovery in P47 out of my mind, Keep power on, do not try pull out by elevator trim, keep ailerons centered , P47 experienced ailerons reversal at high speed, and wait until elevator authority comes back then pull stick to level flight you can use trim to help pulling out of dive.

@kablamoman Very interesting thing is when we look at available over speed rpm. P-51 has 240 excess rpm and P-47 has 350-360 excess rpm available. Despite the fact that P-47's supposed to be more volnurable to excessive rpm. Maybe R-2800's MEB is volnurable but if we stay within permissible limits we should not encounter those engine problems, this is not the first time when ED makes things harder then irl, i will remind only one example, P-51 and famous WEP with logic "you touch it you dying" I remember first iteration of this overdone MEB failure, back then even landing was almost impossible because you could not drop MP below 25" if you did slow process of grinding engine to death had begin. And at 25" slowing this plane down was problematic.

@Art-J I posted also NACA documents which include high speed glide and dive testing of P-47. Which shows that P-47 could be operated with throttle closed and near close even in diving conditions. Other topic is indeed automatic prop governor range, in DCS P-47 very susceptible to overspeed engine completely apposite to P-51 in which you can climb to 48k or so, point nose straight down and level out at 5k ft with not even 10rpm over speed.

Those are from older versions but we can safely assume that maximum permissible diving rpm didn't go down during engine improvements. Edit: I found chart from P-47-25 through P-47-35 in which max permissible diving rpm wen up to 3060rpm. (last chart) Based on those charts we can safely assume that over speeding engine to 3000rpm should not end up with imminent engine catastrophic failure.

Yes, this could be the truth about this stop spot on throttle. ED usually acquire maintenance manuals where those information are included. There is famous topic about P-51 about DCS P-51 thermostats keeping oil and coolant temp too high and some ppl claims that they had to use manual shutter controls to maintain proper temps. But when you look in to P-51's maintenance manual, you can find exact procedure and opening and closing temps for oil/coolant shutter are exact as in game. So in this case 14/18 lbs setup has to be based on something.