Explain me RPM

[Nic727]

Hi,

 

with all infos in the plane description tab, I still can’t figure how to make my RPM works.

 

For example, with the Spitfire, it’s written to use 30´000 RPM for normal navigation. At 30’000, I’m in emergency mode... if I reduce to 20´000 (70-80%) I’m in combat mode between 60-90% throttles. If I use 50% throttle, it’s ok, but I’m just slow and can’t be efficient in dogfight.

 

German planes are easier because it’s all automatic, but American and Russian planes are harder.

 

So, what tips do you have to be fast without blowing up the engine?

 

Thank you

[41Sqn_Skipper]

 

The Spitfire IX engine control is designed so that RPM and throttle are move to the same time and same positions:

Both 100% for 5min combat

Both ~80% for 1hr climb

Both ~60% for unlimited cruise.

 

Same applies dir Spitfire V, just different percentages (and radiator opened as needed.)

With +25 boost mod the throttle must be moved lower, just look at the boost and RPM gauge. 

 

3 hours ago, Nic727 said:

So, what tips do you have to be fast without blowing up the engine?

 

So essentially: For climbing and fast level flight (up to 1 hour) use ~80% RPM and throttle. During combat use 100% RPM and throttle for up to 5 min and when the situation allows it reduce both to ~80%.

3000 RPM for "cruising" is definitly wrong, that RPM is only allowed for take-off and combat/emergency and limited to a few minutes duration.

Edited May 4, 2020 by 41Sqn_Banks

[cardboard_killer]

3 hours ago, Nic727 said:

Russian planes are harder.

 

It's funny as I think Russian planes are the easiest--Yaks get 80- 90% RPM and various throttle depending on what action, while with La-5s get 100% RPM. The American planes are all over the place.

[41Sqn_Skipper]

1 hour ago, cardboard_killer said:

 

It's funny as I think Russian planes are the easiest--Yaks get 80- 90% RPM and various throttle depending on what action, while with La-5s get 100% RPM. The American planes are all over the place.

 

Agreed, in russian planes you mainly need to manage the radiators as you can fly same rpm/boost for unlimited time in all conditions. US are very hard with various settings and quit short limits. British are much easier with only 2 important settings (climb and combat) and reasonable time limits. 30min-1hr "climb" is long enough for all critical conditions without the need for a stopwatch and 5 min "combat" is long enough to get out of trouble. 

[TCW_Brzi_Joe]

2 hours ago, cardboard_killer said:

Yaks get 80- 90% RPM and various throttle depending on what action

Sorry for off topic, but why Yaks 80-90% RPM? Why not 100% all the time? 

I use full throttle and full RPMs on yaks, and manage radiators only.

 

By the way, I would like to improve myself in Spitfires, but they are soo slow in my hands, that I better contribute with bomber ?

[cardboard_killer]

1 hour ago, Brzi_Joe said:

Sorry for off topic, but why Yaks 80-90% RPM? Why not 100% all the time? 

 

At very low altitudes (under 2,000m?) Yaks perform better with slightly lower RPM; I like Yaks, but it's been awhile since I've flown one as I'm working through the BoBp planes. Don't know why but it's discussed here:

 

 

Edited May 4, 2020 by cardboard_killer

[56RAF_Roblex]

Many Russian aircraft are designed to run at 100% rpm & throttle for extended periods.   Not because their engines are better than the British & American fighters,  more to do with the Russians leaders not trusting the pilots to follow rules so they set the levers to make it almost impossible for them to abuse them.  They probably has a point because when those pilots were given British fighters the engines tended to wear out and need fixing or replacing more often than the RAF was used to doing.    

ps Yes the Yaks go a little faster with 90% rpm below 1000m.   

Edited May 4, 2020 by 56RAF_Roblex

[TCW_Brzi_Joe]

3 minutes ago, 56RAF_Roblex said:

ps Yes the Yaks go a little faster with 90% rpm below 1000m. 

All Yaks or just Yak-1 (ser.69)? I use mainly Yak-7 (the humpback one), or Yak-1b, and I heard for that 90% rpm, but never got more speed on 90%. 

[56RAF_Roblex]

4 hours ago, Brzi_Joe said:

All Yaks or just Yak-1 (ser.69)? I use mainly Yak-7 (the humpback one), or Yak-1b, and I heard for that 90% rpm, but never got more speed on 90%. 

 

Sorry.  No the Yak-7b is not faster with reduced RPM.  The Yak-1b at sea level produces 1210bhp with 2700 rpm but gets 1240bhp if you reduce the rpm to 2550.   The Yak-7b can't go over 1210bhp and that is at 2700rpm.    I am not sure why as they both have the same engine though the air intakes on the 7b were slightly different so I suppose there may be some odd but beneficial venturi effect on the 1b with slightly lower rpm.  

Edited May 4, 2020 by 56RAF_Roblex

[RedKestrel]

5 minutes ago, 56RAF_Roblex said:

 

Sorry.  No the Yak-7b is not faster with reduced RPM.  The Yak-1b at sea level produces 1210bhp with 2700 rpm but gets 1240bhp if you reduce the rpm to 2550.   The Yak-7b can't go over 1210bhp and that is at 2700rpm.    I am not sure why as they both have the same engine though the air intakes p teh 7b were slightly different so I suppose there may be some odd but beneficial venturi effect on the 1b with slightly lower rpm.  

I think the CSP unit on the Yak-1s were slightly less efficient at low altitude so there was some speed loss from the propeller if it was set for max RPM, not so much from the engine itself. But I could be mistaken.

[56RAF_Roblex]

9 minutes ago, RedKestrel said:

& think the CSP unit on the Yak-1s were slightly less efficient at low altitude so there was some speed loss from the propeller if it was set for max RPM, not so much from the engine itself. But I could be mistaken.

 

It is possible. The 7b did have a different CSP to that used on the 1 and 1b.

[TCW_Brzi_Joe]

Thank you guys for yak explanation.

 

I do not want to hijack this completely, so please I need a few hints for spit. I tried many times Spit V in Berloga. Usually I put my rpm/throttle to combat settings (max up to 30min I think), and then I go to fight. And I am going, and going, and going, it feels really slow. And then when finally I approach enemy, I add some up trimming and start to dance. Then I have 2 problems:

1) blackouts are too often.

2) ammo is low.

Maybe I am too fast? I do not know. But I do not perform well. I saw once a guy in spit V, and he was just turning vertical, small circles, 3x Messerschmitt couldn't got him. I tried to imitate that, just turning + some rudder, but I was shut down fast.

Any hints?

[ZachariasX]

2 hours ago, Brzi_Joe said:

And I am going, and going, and going, it feels really slow.

Your are probably slow because

2 hours ago, Brzi_Joe said:

1) blackouts are too often.

you fly her like a brute.

 

The Spit has light and effective elevators and she turns incredibly well. However, this is recipe for ending up slow. Don‘t turn into everyone just because the plane seems to let you. Get your speed up to at least 280 mph and don‘t be tempted in following a slower plane in level turn, but turn out of plane in the vertical and be easy on the stick. The Spit can be quick. But you have to take great care for keeping  up with well flown 109F‘s.

 

In the game you have quiet some „timer“ at 2700 rpm, you can max out throttle like that longer, you can even use boost. I only use 3000 rpm in steep climbs.

 

The great turn is only teally relevant when you end up slow on the deck. Then you you can make turns that this scissoring 109 can never follow and you can reposition for a favorable position while he remains on the defensive.

 

3 hours ago, Brzi_Joe said:

2) ammo is low.

True that.

[Stonehouse]

might help 

https://www.avweb.com/features_old/pelicans-perch-15manifold-pressure-sucks/

https://www.avweb.com/features_old/pelicans-perch-16those-marvelous-props/

https://aeroart.co.uk/pages/dowty-rotol

[Heckpupper]

21 hours ago, 56RAF_Roblex said:

 

Sorry.  No the Yak-7b is not faster with reduced RPM.  The Yak-1b at sea level produces 1210bhp with 2700 rpm but gets 1240bhp if you reduce the rpm to 2550.   The Yak-7b can't go over 1210bhp and that is at 2700rpm.    I am not sure why as they both have the same engine though the air intakes on the 7b were slightly different so I suppose there may be some odd but beneficial venturi effect on the 1b with slightly lower rpm.  

 

How the hell is that supposed to work? I get that certain aircraft might be faster with the propeller set to a slightly higher pitch as it's more efficient for high speed, but how in the hell is an engine producing more horsepower with lower RPM?

[ZachariasX]

1 hour ago, ACG_Onebad said:

but how in the hell is an engine producing more horsepower with lower RPM?

Several factors. Valve timings for example, usually in higher revving engines.

 

At some point, upping revs makes any combustion engine drop relative power output:

 

Depending on intake and exhaust arrangement, the volumetric efficiency varies across the rpm band and hence it affects your torque to a different degree. Volumetric efficiancy is what makes your engine lose power above a cartain number of rpm.

 

If the Yak-7b and the Yak-1b have diffenences in intake, this can have an effect. As they have different gun layouts, there might be a difference there.

[41Sqn_Skipper]

2 hours ago, ACG_Onebad said:

 

How the hell is that supposed to work? I get that certain aircraft might be faster with the propeller set to a slightly higher pitch as it's more efficient for high speed, but how in the hell is an engine producing more horsepower with lower RPM?

 

I don't think it has more HP in lower RPM in real life. I suppose it's a workaround to simulate the lower propeller efficiency at high RPM. I mean: if HP were always higher at the lower RPM then there is no reason to use the high RPM anyway, just use different reduction gear ratio for propeller and supercharger and keep the engine running at low RPM all the time.

 

 

[Heckpupper]

2 hours ago, ZachariasX said:

Several factors. Valve timings for example, usually in higher revving engines.

 

At some point, upping revs makes any combustion engine drop relative power output:

 

Depending on intake and exhaust arrangement, the volumetric efficiency varies across the rpm band and hence it affects your torque to a different degree. Volumetric efficiancy is what makes your engine lose power above a cartain number of rpm.

 

If the Yak-7b and the Yak-1b have diffenences in intake, this can have an effect. As they have different gun layouts, there might be a difference there.

 

Yeah that makes sense cheers.

[=RS=Stix_09]

On 5/5/2020 at 5:29 AM, Brzi_Joe said:

Thank you guys for yak explanation.

 

I do not want to hijack this completely, so please I need a few hints for spit. I tried many times Spit V in Berloga. Usually I put my rpm/throttle to combat settings (max up to 30min I think), and then I go to fight. And I am going, and going, and going, it feels really slow. And then when finally I approach enemy, I add some up trimming and start to dance. Then I have 2 problems:

1) blackouts are too often.

2) ammo is low.

Maybe I am too fast? I do not know. But I do not perform well. I saw once a guy in spit V, and he was just turning vertical, small circles, 3x Messerschmitt couldn't got him. I tried to imitate that, just turning + some rudder, but I was shut down fast.

Any hints?

 

1)Only American planes (except the p40/p39) have g suits. This has a reasonable impact on blackouts, and limits high g maneuvers in planes like the spit and tempest.

You can pull more g if you reduce throttle (as this lowers g and allow tighter turns). And you don't want to only fly full throttle in a dogfight, if that is what u are doing...

 

2)In my opinion its better to do energy fighting over turn based tactics, regardless of plane.

Don't attack on  less energy , only defensive flying in that scenario. Get away and comeback with more energy. If defensive your goal is to lower your opponents energy and increase yours.

On equal energy, "maybe" in a plane that turns better , but I would only do that if both planes are at low energy state as this give better turning plane an advantage under that condition. It also depends on potential energy (altitude) available, there is more risk doing this.

 

Only engage in turn tactics if your target is also low on energy and if you  have a advantage (its a last resort flying style, or used in defense.) When you are low on energy even if you have advantage on your target, you are very venerable to being attacked by someone else. Its a very risky solo attack. You do not want to be here,

 

Turn based fighting should never be a primary method to dogfight, doesn't matter the plane.

These are "general" rules I fly by and most experienced pilots do this.

 

Edited May 6, 2020 by =RS=Stix_09

[TCW_Brzi_Joe]

Well, I got some success With taking your advices, I was really easy on stick, and spit was following my lead as a leaf. I was not sucked into turn fight, rather I was going up. That confused my enemies, and me sometimes

I still have to free myself of fear that engine will blow up when in full throttle/rpm. I have 5min there, but I expect it after first minute.

Btw, how much time is needed for recover power?

And 1 new problem, now if I turn, and somebody is on my 6, then or:

a) With easy on stick I am not turning enough, he got me

b) I pull stick more and more, and eventually I got blackout, he got me.

 

Ps: I do understand turning, reducing speed, trimming, flaps, yoyos, and generally I am not bad in yaks or 109f/g

[ZachariasX]

1 hour ago, Brzi_Joe said:

a) With easy on stick I am not turning enough, he got me

Unless you are fast enough to pull sufficient g's for a blackout, the attacker at your 6 will have a firing solution on you. That is the moment you are dead and you just don't know it yet. The tight turn is only good if the attacker is very close to you at roughly equal speed. A 109 driver that knows what he is doing will come in fast and if he reaches your 6 and you then cannot force a blackout turn, you're a goner. He will also not turn with you if he's very fast, but extend and climb to maintain the initiative.

 

1 hour ago, Brzi_Joe said:

b) I pull stick more and more, and eventually I got blackout, he got me.

You cannot just pull quickly and black out, as in this little time you do not fly far, meaning you are not producing a lot of angles to your assailant. If you are fast enough for a blackout turn you still must try to keep as much speed as possible while slowly going into a turn. Your speed will prolong the time required for the bandit to enter a firing solution. During this time, you force him to turn with you. It requires him to lead your turn to be positioned for a snapshot. This is where he both bleeds more energy than you as well he is receicing more g's than you are. Hence he's in a worse position to follow you in a turn when you start to tighten the turn.

 

It is of paramout importance that you keep tracking your attacker and pull only so far that you see his plane directly ahead. If you are looking down his gun barrels while doing a gentle turn, he cannot hit you. His shots will lag you. You should be at least at 4 g (just slightly below the onset of g effects) turning to prevent him for a quick pull and snapshot before he blacks out. Tightening is the moment just before he treaches the distance for a snapshot.

 

If he is very fast (still significantly faster than you), he will abort the turn quickly, else he will black out. You MUST keep your eyes on him to see that very moment. It is then when he will start to overshoot you and you will reverse your turn and start a scissor placing him in front to you. If he was careless, the turn will both have bled his speed for not extending fast as well as he will have a hard time maneuvering due to g effects. It is then when you can reverse the situation.

 

The bottom line is still, the slower of the two has no mean of escaping the faster one. Only when speeds are reasonably similar, the slower on can force the faster one into maneuvers. Tight circles at slow speed just make it harder for the other taking shots at you, but you you remain on the plate for him.

[Tipsi]

On 5/4/2020 at 6:29 PM, Brzi_Joe said:

1) blackouts are too often.

try increasing your joystick sensitivity.

 

go to options, key bindings, click the swirly graph under:

 

pitch, roll, and yaw.

 

try adding 50% sensitivity to each.

 

you may find you are blacking out less now because you need to “pull more” on the stick to use the elevators.