Author Topic: manifold presures and throttle ?  (Read 204 times)

freak-

  • Guest
manifold presures and throttle ?
« on: September 29, 1999, 03:38:00 AM »
system used on:
dual p2400 (dual no active till NT installed or win 2000)
128 meg ram
2x voodoo2 12 megs (SLI)
creative labs pci64v
33.6 modem
microsoft sidewinder presision pro

hi guys
now i dont know if i was doing something wrong last night, but i couldnt get the p51 to go any faster than 250, even when i dropped all my ord, i just seemed to climb to slow, and always wanted to stall. in level flight it never went over 300 ?
i re calibrated my joystick in the game, and it was working ok.
manifold presure on all planes maxed out at 60, 70 with wep engaged, is this right for all planes ??

cheers.


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[This message has been edited by freak- (edited 09-29-1999).]

foggia

  • Guest
manifold presures and throttle ?
« Reply #1 on: September 29, 1999, 07:16:00 PM »
With this SIM you have two ways to control the thrust output of your aircraft.  One is by controlling the power output of the engine (manifold pressure).  The other is the pitch of the prop (greater pitch means more speed, but results in lower propeller speed ...  less pitch means higher propeller speed, but more climb ability).  Use your keypad minus and plus keys to control the propeller RPM (and pitch).  To go faster, just reduce propeller RPM at the same manifold pressure setting.  BTW, always take off with the highest propeller RPM possible.

Another thing I found is that when you engage WEP, the A/C automatically advances to the highest possible propeller RPM and will not allow you to adjust it, i.e.  WEP is for hanging on the prop!  It won't give you that extra bit of speed that it used to in "other" sims.

Offline Jinx

  • Zinc Member
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  • Posts: 3
manifold presures and throttle ?
« Reply #2 on: September 30, 1999, 04:37:00 AM »
Well.. The prop pitch can be seen like the gearbox on a car. The engine outputs max torque and max horsepower at a given rpm. Usually not the same rpm for both though, but to (over)simplify things we can say the engine outputs the most power to the prop at max rpm. Its the same thing as a car having a higher top speed on fourth gear then fifth gear as long as the engine is not over revving, it just doesn’t have the power to reach max rpm in fifth gear.

The only real reason to not use the highest possible rpm is to save fuel (and the engine in a real plane). Remember that the prop is constant speed, it will try to adjust the pitch automatically to the increased air speed and reducing the rpm manually will not make the plane go faster but slower.  

At least that is how I understand the implementation in AH right now, there are many more factors to take into account in real life but not in the sim yet. Max rpm and max manifold pressure gives max Power and that is what WEP gives you automatically, it doesn’t matter if you want climb performance or top speed.

   -Jinx



funked

  • Guest
manifold presures and throttle ?
« Reply #3 on: September 30, 1999, 10:52:00 AM »
Jinx is right, most WW2 engines put out more power at higher RPM settings.

Offline Checkmate

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  • Posts: 2
      • http://home.stny.lrun.com/mhanger
manifold presures and throttle ?
« Reply #4 on: September 30, 1999, 12:30:00 PM »
  Well, This is one person that needs to go back and read all those FAQs and such. I didn't "catch" that you had control of RPM and Manifold pressure. Cool !  Makes me understand a bit more about my first 3 flights to date   Thanks for the tips !

After thinking about it, I have one question. Is the RPM "digital"? (Either High or Low). Or are there "steps" to it (and how many steps between Hi and Low). Thanks again.


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-ckmt-
1./JG14

[This message has been edited by Checkmate (edited 09-30-1999).]

funked

  • Guest
manifold presures and throttle ?
« Reply #5 on: September 30, 1999, 12:52:00 PM »
-ckmt-

There are steps.  

Apparently the modeling is not finished yet.  One of the HTC guys said that the best bet for now is to run max RPM.  Also last night I seemed to be able to run WEP indefinitely.  I think in later versions we will see effects on fuel consumption, oil pressure/temp, coolant temp, etc.  Then you will have to manage the engine and prop to get a compromise between thrust/fuel/stress that suits the current situation.

For now run wide open with WEP and max RPM.