Author Topic: throttle:Manifold vs Engine rpm (Read 904 times)

ridley1 · « **on:** February 13, 2006, 02:46:29 PM »

I use a logitech extreme 3d pro (yeah...I know...thought it wasw a good deal at the time....but I digress)

I hit the throttle on the stick....Man press falls, but rpm stays the same....
hit the +- on the keyboard.....both rpm and man pressure change....

what is the secret to the modelling here?

USHilDvl · « **Reply #1 on:** February 13, 2006, 03:15:43 PM »

The "+" and "-" keys control prop pitch, which translates to changes in RPM (the RPM gauge is a measure of prop RPM, not engine).

When you change the prop RPM, there is an effect on engine manifold pressure as the workload decreases/increases. Increased pitch = increase workload and vice-versa. As you reduce prop RPM, the max engine manifold pressure will drop with it, so you see 'both' settings move.

To set a specific engine config (like Max Cruise) first set the RPM, then make final adjustments to your manifold pressure (throttle).

Hope this clears it up a bit!

Golfer · « **Reply #2 on:** February 13, 2006, 03:26:45 PM »

Pfffft just leave them both full forward. Who really knows what they're for anyways?

Mustaine · « **Reply #3 on:** February 13, 2006, 03:33:35 PM »

Quote

Originally posted by Golfer
Pfffft just leave them both full forward. Who really knows what they're for anyways?

good answer

USHilDvl · « **Reply #4 on:** February 13, 2006, 03:36:56 PM »

...and probably the more correct one!!

Furball · « **Reply #5 on:** February 13, 2006, 03:50:41 PM »

i like the p button.

p is for pwn.

wetrat · « **Reply #6 on:** February 13, 2006, 04:41:56 PM »

p is for peni....
wait, nevermind.

eilif · « **Reply #7 on:** February 13, 2006, 05:53:24 PM »

with AH's "engine management for idiots" you dont really need to mess with rpm unless your trying to conserving fuel.

Widewing · « **Reply #8 on:** February 13, 2006, 07:22:17 PM »

Quote

Originally posted by eilif
with AH's "engine management for idiots" you dont really need to mess with rpm unless your trying to conserving fuel.

Besides, a common USAAF maxim was "everything forward until the sky is empty".

My regards,

Widewing

Brooke · « **Reply #9 on:** February 14, 2006, 02:37:37 AM »

Throttle and manifold setting is occasionally useful in scenarios, squad ops, snapshots, planned missions, etc.

Hades55 · « **Reply #10 on:** February 15, 2006, 02:37:46 AM »

Some here they dont know what they are talking about, or they create confusion for their own reasons....

Anyway, + and - controls the Rotation Per Minute (RPM) of your engine
and you can hear it. Very usufull when you try to rtb without fuel.

(many times i return all way back with 1500-1800 RPM burning just air

.

Throttle controls the pits of the wings of your propeller so the manifold pressure ( the amount of air who your propeller send back) change but not the RPM (who stay the same if you are not change them with + -).

Golfer · « **Reply #11 on:** February 15, 2006, 03:03:07 AM »

Quote

Originally posted by Hades55
Some here they dont know what they are talking about, or they create confusion for their own reasons....

Quote

Throttle controls the pits (Pitch) of the wings of your propeller so the manifold pressure ( the amount of air who your propeller send back) change but not the RPM (who stay the same if you are not change them with + -).

I think that created more confusion than anything. While technically correct...that's a Microsoft Tech Support answer if there ever was one.

Regardless of your throttle setting, using the propeller control (NUM+/NUM-) the propeller will spin at a constant rate in terms of RPM. Hence the term "Constant Speed"

The throttle setting is a measure of how much "oomph," which is a very technical aeronautical term, the motor is giving to the propeller.

TequilaChaser · « **Reply #12 on:** February 15, 2006, 05:13:26 AM »

as Golfer has just stated regarding RPM's control keys.........

the keyboard control keys for throttle are - & = . Now you can use SHIFT - for instant off/no throttle or use SHIFT = for instant 100% throttle/wide open .

the control keys for the RPM's are on the numbers keybad which Golfer stated in his last reply, which are - for lowering RPM & + for raising RPM........

so in that info you can find out why you was getting confused.......

check out the help section/getting started and look for the key commands link for more detail......

Good Luck!

USHilDvl · « **Reply #13 on:** February 15, 2006, 10:57:44 AM »

Confusion is right, Hades...

Its revolutions per minute, not rotations.

The gauge reads propellor RPM, not the engine RPM.

Manifold pressure is NOT the amount of air the prop pushes back.

Manifold pressure IS the pressure of the gasses currently passing through the intake manifold.

As Golfer pointed out, a constant speed prop maintains rpm regardless of throttle/manifold setting via automatic pitch adjustment. Changing the RPM setting alters the actual constant rpm to be maintained.

Hades55 · « **Reply #14 on:** February 15, 2006, 11:35:25 AM »

I was speaking about the *numbers keypad + and -* not the keyboards ones who needs shift.

To make it simpler the + and - at numbers keypad is like the gas pedal of
your car. You control the rotation of your engine. More RPMs more gas needed but also more HP (horse power).

Now, Throttle controls the pitch, means the angle of the wings of the propeller who they cat the air, as the prop turns.
More angle more air goes back more power pull your plane frond.

You can have Full RPMs at your engine but when your pitch is 0 no air goes
back so your plane dont move.