Author Topic: Bug in P-51B throttle mapping?  (Read 279 times)

Offline oboe

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Bug in P-51B throttle mapping?
« on: May 26, 2018, 05:27:22 PM »
I've been flying the P-51B more often and had noticed some jumping in the Manifold Pressure needle as I accelerate down the runway on take-off.  I first thought my throttle pot needed cleaning, so I brought up Options/Controllers/Map Controllers, selected Z-Rotation (mapped to Analog Throttle 1) and checked the advanced box so I could watch the throttle input - result was smooth input throughout the range of throttle rotation.

So next I got in the P-51B and set it to Auto-Take off.  I brought up the clipboard and went to the Advanced box again so I could watch the throttle axis input.  As I smoothly and slowly advanced the throttle on take-off, I compared the throttle input to the manifold pressure gauge needle.  Both rose slowly and steadily as my throttle was advancing.  Until, at about 44", the needle suddenly dropped to 35".   I hadn't paused in advancing the throttle, but continued slowly increasing my input.  The needle continued to rise again slowly, commensurate with my throttle input until I reached about 44" again - then it really took off and advanced much more rapidly than before, even though I hadn't changed my rate of advance on the throttle.

I also tried this experiment on the P-51D but the throttle input and manifold pressure needle seemed properly linked through out the range - I've only noticed this in the P-51B.

Can any one else verify this, pls?    Thanks!

Offline 1stpar3

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Re: Bug in P-51B throttle mapping?
« Reply #1 on: May 27, 2018, 12:19:21 AM »
Wasnt EXACTLY as you described...but noticed A MARKED jump up in MP from 44 to full. It was smooth and regular to about 35 slowed a bit to 44 then POOF full manifold. Backing off was same way...real fast down to 44...a bit of a crawl to 35...then steady to 10.
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Offline Vraciu

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Re: Bug in P-51B throttle mapping?
« Reply #2 on: May 27, 2018, 12:23:20 AM »
Similar results here.   I thought it was my stick.
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Offline oboe

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Re: Bug in P-51B throttle mapping?
« Reply #3 on: May 27, 2018, 07:32:53 AM »
Thanks for testing this guys.