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-   -   P100 accelerating issue (http://www.rcuniverse.com/forum/rc-jets-120/11203964-p100-accelerating-issue.html)

Eddie Lozano 08-23-2012 05:12 PM

P100 accelerating issue
My P100 would not accelerate. When I move the throtle stick up the engine would not spool up instead it cough then stop. Any idea whats going on.


Vincent 08-23-2012 05:56 PM

RE: P100 accelerating issue
Move your idle throttle setting from normal to slow or extra slow.

Eddie Lozano 08-23-2012 06:32 PM

RE: P100 accelerating issue
Thanks Vince

Eddie L


Jeffpro 08-24-2012 03:29 AM

RE: P100 accelerating issue
I had the same issue with my P100-RX. Like Vin said, go to IdleThrottleResponse in the ECU and set it to Slow or Very Slow. Most of the 100s seem to be sensitive to temperature and humidity, so when the weather cools down, you may be able to go back to Norm. I flew mine last weekend on Very Slow and the throttle response was actually quite good.

Jack Diaz 08-24-2012 05:37 AM

RE: P100 accelerating issue
The misleading issue are the names "Fast", "Normal", "Slow" and "Very Slow".

In my opinion, the ECU idle settings should be thought of as an "Idle Needle Valve adjustment"; which should be adjusted to produce the fastest and more reliable idle response at a particular filed condition, regardless of the position of the needle.

At the field where I fly, the fastest response is almost always obtained with less fuel (Slow or Very Slow).

The number of Oxygen molecules per volume of air, reduces with higher temperature, humidity and altitude. Therefore, fuel flow should be adjusted to maintain the correct fuel to air mixture.

In other words, the fastest you are going to get, is when the mixture is correct. Faster than that is thermodynamically impossible, no matter what the ECU says.

Eddie, are you going to Best in the West?


Chris Smith 08-24-2012 10:45 AM

RE: P100 accelerating issue
On a positive note it is amazing the power smaller packages are putting out.

But it seems at this point in model turbine development the ECU should know the temp, humidity, and altitude, even if they are user inputs. Then the ECU should utilize a look-up table and make the appropriate settings. I realize we still don't have true FADEC capability but it shouldn't be that hard. More user fiddling on new engines doesn't seem like a step forward.

bluescoobydoo 08-24-2012 11:02 AM

RE: P100 accelerating issue
thats what i was just thinking when i was reading your post, i have never had to adjust any of my wrens from when i fly in the winter to summer so why can't the jet cats decide there own settings, what would happen if the jetcat decided it needed adjustment while you were flying?

3d flip 08-24-2012 11:32 AM

RE: P100 accelerating issue
The V10 ECU has a barometric pressure sensor

Barom.Auto Tune Enables the ECU to align the control system according the barometric pressure.

The possible settings are:

Disabled: No auto tuning by ECU
IdleRPM-Set: Optimize of idle RPM only
Ramp-Set: Optimize of acceleration only
Idle&Ramp-Set: IdleRPM and acceleration are optimized

Jeffpro 08-24-2012 01:42 PM

RE: P100 accelerating issue
Correct about the V10 ECU. However, I tried it and it didn't work. (The turbine would cough, belch flames, and quit when I gave it fuel.) I spoke to Bob Wilcox about it and he said the auto feature hasn't proven to be very reliable. I'm guessing that's because barometric pressure is only one of the variables (humidity being another).

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