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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Dennis Toth on February 22, 2011, 09:58:55 AM

Title: Lap time change in warm weather?
Post by: Dennis Toth on February 22, 2011, 09:58:55 AM
Guys,
The past weekend the weather started to warm here in south FL and I noticed a change to the lap time on my Stuka by about 1.5sec slower. The battery drain was also lower. This seems to point to a reduced load due to the lower density of the warmer air (75F vs 60F for the past month). It appears that for electrics as the air density changes we need to have either several props with different pitches or need to reset the rpm to a higher value. This makes a certain amount of sense since our systems hold rpm electrically not relying on load to hold it back.

Has anyone else notice this on their setups?

Best,         DennisT
Title: Re: Lap time change in warm weather?
Post by: Howard Rush on February 22, 2011, 01:23:49 PM
We discussed this in another thread.  From what I can tell, both thrust and drag should be proportional to density, so lap time would be about the same.  My guess is that something else in your system changed.
Title: Re: Lap time change in warm weather?
Post by: Dean Pappas on February 22, 2011, 02:11:26 PM
Yes, Dennis,
There will be a slowdown and a reduction in power consumption.
The slowdown should be a handful of hundredths of a second and the power reduction less than 5 or 10%.
There is something else happening in your system.
Dean P.
Title: Re: Lap time change in warm weather?
Post by: Russell Bond on February 22, 2011, 07:47:38 PM
I also noticed a slight increase in lap times in hot weather. I'll check it out the next hot day, but I think it was about .05 slower.
I've also found the lap times are faster in windy weather. From 5.6 down to 5.5/lap and in windy weather the plane uses less battery power than in calm.
Title: Re: Lap time change in warm weather?
Post by: Wynn Robins on February 23, 2011, 05:23:31 PM
I also noticed a slight increase in lap times in hot weather. I'll check it out the next hot day, but I think it was about .05 slower.
I've also found the lap times are faster in windy weather. From 5.6 down to 5.5/lap and in windy weather the plane uses less battery power than in calm.


could be just your reflexes on the stopwatch at .01 difference  S?P
Title: Re: Lap time change in warm weather?
Post by: Russell Bond on February 23, 2011, 06:59:23 PM
Haha, not .01, it was .05 difference. Plus I timed it over 2 laps.   ;D