Aces High Bulletin Board
General Forums => Aircraft and Vehicles => Topic started by: Helm on April 19, 2014, 06:24:29 PM
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As you probably know you can lower you fuel consumption by adjusting the RPM and throttle settings. My question which do you do first?
Helm ...out
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Helm, after piddling, I'm an RPM guy. In a 40, 25 or 11 jug, put your rpm to 20. Happy days ensue!
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As you probably know you can lower you fuel consumption by adjusting the RPM and throttle settings. My question which do you do first?
Helm ...out
Reducing power, reduce throttle/manifold pressure then prop/RPM. To increase power, increase prop/RPM, then throttle/manifold pressure.
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It's worth having the E6B open to show range remaining etc then play around with revs and boost, see what setting seems to do best for what you need.
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Reducing power, reduce throttle/manifold pressure then prop/RPM. To increase power, increase prop/RPM, then throttle/manifold pressure.
:cheers: Correct, but don't expect engines in this game to react as the real ones did. They have done a pretty good job modeling these engines in the game, but when fooling with throttle and RPM, consult E6B for gest results and do it as "Puma" points out.
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:cheers: Correct, but don't expect engines in this game to react as the real ones did. They have done a pretty good job modeling these engines in the game, but when fooling with throttle and RPM, consult E6B for gest results and do it as "Puma" points out.
Ditto on the gameness. I have noted that with the E6B open when adjusting manifold pressure and RPM, endurance time responds in what appears to be an appropriate manner. Of course, the game most likely can't simulate the environmental affects and age/mechanical health of the engine(s). More than once, adjusting manifold pressure and rpm has given me enough endurance to make it back a safe landing vs landing short at some farmer's field.
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HTC set the fuel burn rate at 2/1 for game balance. If set at 1/1, we would find short-legged, high performance interceptors over bases 100 miles from their take off field. Thus, you don't see swarms of La-7s two sectors from their base. A big part of the balance issue solution is that most want to get to a fight ASAP. It works because most players firewall the throttle and keep it there all the way to the destination.
If you want to fly those types of fighters that don't have a drop tank option (La-7 and Yaks for example) long distances (comparatively), you must accept the fact that the ingress and egress legs will take longer to do so. Just open E6B and take a look at the various power settings. Normal power still burns too much fuel. So, depending upon the range you need, you select the power setting that best suits your need. Just keep in mind that an La-7 will burn down fuel at a very fast rate using WEP. So, leave yourself a good margin for combat. In many cases, you can double your range using the most efficient cruise setting. Also keep in mind that when you decide to RTB, you won't be able to power back until clear of the enemy. So, factor that into your fuel plan too. In bombers, speed is your best defense against interception. So, most players will not use fuel saving power settings. In the case of bombers, the player is already resigned to a long flight to and from the target.
As to how to set cruise power... In the real world, you would throttle back first, and then adjust your RPM. Likewise on power-up, you would first increase RPM and then add throttle. Do either process in the reverse order, and you risk over-boosting the engine, which can cause detonation and result in damage.
This is not the case in Aces High. The engine cannot be damaged. So, you may use whatever sequence you prefer.
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HTC set the fuel burn rate at 2/1 for game balance. If set at 1/1, we would find short-legged, high performance interceptors over bases 100 miles from their take off field. Thus, you don't see swarms of La-7s two sectors from their base. A big part of the balance issue solution is that most want to get to a fight ASAP. It works because most players firewall the throttle and keep it there all the way to the destination.
If you to fly those types of fighters that don't have a drop tank option (La-7 and Yaks for example), you must accept the fact that the ingress and egress legs will take longer to do so. Just open E6B and take a look at the various power settings. Normal power is still burns too much fuel. So, depending upon the range you need, you select the power setting that best suits your need. Just keep in mind that an La-7 will burn down fuel at a very fast rate using WEP. So, leave yourself a good margin for combat. In many cases, you can double your range using the most efficient cruise setting. Also keep in mind that when you decide to RTB, you won't be able to power back until clear of the enemy. So, factor that into your fuel plan too. In bombers, speed is your best defense against interception. So, most players will not use fuel saving power settings. In the case of bombers, the player is already resigned to a long flight to and from the target.
As to how to set cruise power... In the real world, you would throttle back first, and then adjust your RPM. Likewise on power-up, you would first increase RPM and then add throttle. Do either process in the reverse order, and you risk over-boosting the engine, which can cause detonation and result in damage.
This is not the case in Aces High. The engine cannot be damaged. So, you may use whatever sequence you prefer.
:airplane: As usual WW, you make some good and valid points about the game. <S> to you sir for your service to your country and help here in this game!
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HTC set the fuel burn rate at 2/1 for game balance. If set at 1/1, we would find short-legged, high performance interceptors over bases 100 miles from their take off field. Thus, you don't see swarms of La-7s two sectors from their base. A big part of the balance issue solution is that most want to get to a fight ASAP. It works because most players firewall the throttle and keep it there all the way to the destination.
If you want to fly those types of fighters that don't have a drop tank option (La-7 and Yaks for example) long distances (comparatively), you must accept the fact that the ingress and egress legs will take longer to do so. Just open E6B and take a look at the various power settings. Normal power still burns too much fuel. So, depending upon the range you need, you select the power setting that best suits your need. Just keep in mind that an La-7 will burn down fuel at a very fast rate using WEP. So, leave yourself a good margin for combat. In many cases, you can double your range using the most efficient cruise setting. Also keep in mind that when you decide to RTB, you won't be able to power back until clear of the enemy. So, factor that into your fuel plan too. In bombers, speed is your best defense against interception. So, most players will not use fuel saving power settings. In the case of bombers, the player is already resigned to a long flight to and from the target.
As to how to set cruise power... In the real world, you would throttle back first, and then adjust your RPM. Likewise on power-up, you would first increase RPM and then add throttle. Do either process in the reverse order, and you risk over-boosting the engine, which can cause detonation and result in damage.
This is not the case in Aces High. The engine cannot be damaged. So, you may use whatever sequence you prefer.
All these years and I never knew you could control rpm/throttle independently :uhoh
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The E6B is your friend. You can adjust either setting manually, but using the - or + key on the numerical pad goes a long way in simplifying things. All in all, just get to your desired altitude and then read the settings in the E6B.
You'd be VERY surprised how far you can push that otherwise short legged plane once the throttle is managed. The La7 and Yak-3 are the best examples of this. The Spitfire Mk IX is another very good example. 190's, etc.
Nothing like doubling your time of flight and still doing 330+ TAS. If the squeakers would quit with the full throttle they'd get more satisfaction in range.
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I reduce the prop rpm on the LA7 as soon as the engine gets to full power on takeoff. Works like a charm!
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What is the advantage/disadvantages of changing prop rpm vs adjusting the throttle?
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You could always climb to 35K. I hear it saves fuel.
:noid
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You could always climb to 35K. I hear it saves fuel.
:noid
(looks at feet an whistles nonchalantly)
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What is the advantage/disadvantages of changing prop rpm vs adjusting the throttle?
In game I don't know. Real life on normally aspirated airplanes the most efficient way to run is wide open throttle(at a high enough altitude that you're only putting out 75% power +/-), with RPM at cruise, mixture leaned appropriately.
On supercharged or turbocharged engines reducing RPM can cause a power reduction due to reducing supercharger or turbo speed with a resulting drop in manifold pressure.
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The P38s in the pacific were running at high throttle and reduced RPM at the advice of Lindberg. They initially feared that this will wear down the engines, but found it was not so bad.
Lots of energy is lost on moving parts. Less RPM means the parts are moving leas, though there some counter effects so low RPM and high throttle is not a pure gain.
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What is the advantage/disadvantages of changing prop rpm vs adjusting the throttle?
:airplane: Rather than go into a lot of detailed engineering explanation, consider this: If you have your prop control or controls to the full increase position, the prop blades will be in their "flattest" position and will allow the engine to turn maximum RPM. This position is good for climbing or carrying heavy loads. It does nothing to promote hi speed in the full increase position.
If it is speed you are after, you must know at what RPM on Tachometer your prop blades are the most efficient, with a full open throttle!
There are many factors to consider when operating air cooled aircraft engines. If you constantly run hi manifold pressure settings and low rpm's, you are going to burn a hole in the top of the cylinder piston.
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Here's an excerpt from an article about Lindbergh and the Pacific P-38s found via Google. Interesting read.
"First one, then two pilots reported dwindling fuel and broke off for home. MacDonald ordered the squadron back but because Lindbergh had nursed his fuel, he asked for and received permission to continue the hunt with his wingman. After a few more strafing runs, Lindbergh noticed the other Lightning circling overhead. Nervously the pilot told Lindbergh that he had only 175 gallons of fuel left. The civilian told him to reduce engine rpms, lean out his fuel mixture, and throttle back. When they landed, the 431st driver had seventy gallons left, Lindbergh had 260. They had started the mission with equal amounts of gas.
Lindbergh talked with MacDonald. The colonel then asked the group's pilots to assemble at the recreation hall that evening. The hall was that in name only, packed dirt floors staring up at a palm thatched roof, one ping pong table and some decks of cards completing the decor. Under the glare of unshaded bulbs, MacDonald got down to business. "Mr. Lindbergh" wanted to explain how to gain more range from the P-38s. In a pleasant manner Lindbergh explained cruise control techniques he had worked out for the Lightnings: reduce the standard 2,200 rpm to 1,600, set fuel mixtures to "auto-lean," and slightly increase manifold pressures. This, Lindbergh predicted, would stretch the Lightning's radius by 400 hundred miles, a nine-hour flight. When he concluded his talk half an hour later, the room was silent.
The men mulled over several thoughts in the wake of their guest's presentation. The notion of a nine-hour flight literally did not sit well with them, "bum-busters" thought some. Seven hours in a cramped Lightning cockpit, sitting on a parachute, an emergency raft, and an oar was bad, nine hours was inconceivable. They were right. Later, on 14 October 1944, a 432nd pilot celebrated his twenty-fourth birthday with an eight-hour escort to Balikpapan, Borneo. On touching down, he was so cramped his crew chief had to climb up and help him get out of the cockpit.
The group’s chief concern surfaced quickly, that such procedures would foul sparkplugs and scorch cylinders. Lindbergh methodically gave the answer. The Lightning's technical manual provided all the figures necessary to prove his point; they had been there all along. Nonetheless the 475th remained skeptical. A single factor scotched their reticence.
During their brief encounter, MacDonald had come to respect Lindbergh. Both men pushed hard and had achieved. Both were perfectionists never leaving things half done. And both had inquisitive minds. John Loisel, commanding officer the 432nd, remembered the two men talking for long periods over a multitude of topics beyond aviation. If, as MacDonald had informed his pilots, better aircraft performance meant a shorter war, then increasing the Lightning's range was worth investigating. Lindbergh provided the idea, but it was MacDonald's endorsement, backed by the enormous respect accorded him by the group, that saw the experiment to fruition. The next day, the Fourth of July, Lindbergh accompanied the 433rd on a six-hour, forty-minute flight led by Captain "Parky" Parkansky. Upon landing, the lowest fuel level recorded was 160 gallons. In his journal entry Lindbergh felt ". . . that the talk last night was worthwhile. " The 475th had lengthened its stride."
:salute
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Gross power output of an engine is linearly related to the volume of air fuel mixture traveling threw the engine.
There are 2 ways to "PUMP" more air threw the engine , one is make the pistons pump the air faster (i.E. higher rpm) the other is increasing the density/pressure of the air entering (throttle) the cylinder but keep the RPM constant.
Increasing RPM creates more friction in the engine, and hence less efficiency then increasing throttle which does not increase the friction.
HiTech
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Gross power output of an engine is linearly related to the volume of air fuel mixture traveling threw the engine.
There are 2 ways to "PUMP" more air threw the engine , one is make the pistons pump the air faster (i.E. higher rpm) the other is increasing the density/pressure of the air entering (throttle) the cylinder but keep the RPM constant.
Increasing RPM creates more friction in the engine, and hence less efficiency then increasing throttle which does not increase the friction.
HiTech
:airplane: Your point about the friction is correct, but what you forgot to mention is with high manifold settings the dynamic force of added fuel and air in the cylinder can and will do damage to the engine in the long run. Scored intake valves and holes burned into the piston heads. While"Lindy" did extend the range of the 38's as well as some other aircraft, the damaged to the engines in the long run resulted in a higher frequency of inspection and cylinder replacements. I can't exactly give you the bulletin which changed the inspection procedures, but the "Ponie" drivers in Europe experienced higher maint. time per flight hour than before using his method of fuel conservation.
The D and B model will go a long way on 2,000RPM and 32 inches of manifold pressure, but you will piss off the crew chief when he finds out about it.
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:airplane: Your point about the friction is correct, but what you forgot to mention is with high manifold settings the dynamic force of added fuel and air in the cylinder can and will do damage to the engine in the long run. Scored intake valves and holes burned into the piston heads. While"Lindy" did extend the range of the 38's as well as some other aircraft, the damaged to the engines in the long run resulted in a higher frequency of inspection and cylinder replacements. I can't exactly give you the bulletin which changed the inspection procedures, but the "Ponie" drivers in Europe experienced higher maint. time per flight hour than before using his method of fuel conservation.
The D and B model will go a long way on 2,000RPM and 32 inches of manifold pressure, but you will piss off the crew chief when he finds out about it.
If that is the only way to achieve the range to do the missions, then I suppose they were willing to pay the price. How much it damages the engine probably varies significantly from engine to engine. Maybe the Allisons were more resistant to such abuse than the Merlins.
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:airplane: Your point about the friction is correct, but what you forgot to mention is with high manifold settings the dynamic force of added fuel and air in the cylinder can and will do damage to the engine in the long run. Scored intake valves and holes burned into the piston heads. While"Lindy" did extend the range of the 38's as well as some other aircraft, the damaged to the engines in the long run resulted in a higher frequency of inspection and cylinder replacements. I can't exactly give you the bulletin which changed the inspection procedures, but the "Ponie" drivers in Europe experienced higher maint. time per flight hour than before using his method of fuel conservation.
The D and B model will go a long way on 2,000RPM and 32 inches of manifold pressure, but you will piss off the crew chief when he finds out about it.
Pissing off the crew chief is right at the top of the list of things a fighter jock can screw up.