Carb heat effect is delayed
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After startup and before taking off, the Warrior's checklist indicates to test the carb heat at the holding point with engine at 1700rpm. In the real plane, pulling down the carb heat should drop the rpm immediately, with no delay.
In this simulation, the effect is delayed by about 20 seconds from the time the carb heat is pulled down.
Could someone from JF comment on:
- why it was modelled this way, and
- what parameter I could change to fix this ? I bought the plane from JF's directly so I can amend the cfg files.
This issue appears only the first time the carb heat is pulled down after startup. Subsequently, the effect is immediate as it should be.
I took the time to record the issue and upload it on youtube at the below link, would appreciate a response.
Thank you
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@katchaplin Including the first time you pull it down after start up ?
(again, I only have this problem the first time I pull it down. After, no issue)
At what RPM do you do your engine check ? I've done some testing and in my case the delay seems to be dependent on the RPM during the engine check.
- 2400 RPM: 1 second delay. So this is realistic.
- 2000 RPM: 5 seconds delay
- 1700RPM: 30 seconds delay
- 1500 RPM: there is no drop at all no matter how long I wait
I'm looking at the manual of the P28 we have at the local airclub I'm flying with, they say to do the engine check at 2000 RPM. Our checklist in the plane however says 1700 RPM. So... I guess I could do my engine check at 2000 RPM for a 5 seconds delay only. But still, I would like to understand from JF the reason for this delay I'm having.
I should have mentioned that I have uninstalled the plane and reinstalled it to make sure it wasn't anything I had amended myself in the cfg files.
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Seems I can't edit my post anymore.
Actually if it's not too much trouble, can you check the above 4 scenarios, as in carb heat hot with engine 1500, 1700, 2000 and 2400rpm and see what you get ?
For each scenario, you will need to exit the scenario completely and re-load it and start again from cold and dark. -
@katchaplin Ok, thanks for checking, appreciate it. I'm assuming that this was tested at the first time after startup (I insist that this happens the first time only, and only on freshly loaded scenery - clicking the "cold and dark" button on the EFB isn't sufficient to replicate what I'm experiencing).
Are you using v.0.3.5 dated 30/6 ?
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The ONLY carb heat adjustments we can make in the engine.cfg file (and as far as I am aware, there is no code which will impact on this, it is just using the core game SDK entries) are:
carb_heat_delta_temp=55
carb_icing_sensiblity=0.25Anything to do with the timing has to be calculated by the game itself from the figures we put for those two entries. Logically, therefore, the answer should be the same each time the game calculates it. If not, I'd say that the game is the problem because as you can see there is nothing which would allow us to specify different behaviour for any particular instance of adjustment.
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Thanks for the response, I see you are a JF developper, great news.
What could be the cause of this issue with the sim ? Presumably you have tested this plane with MSFS2020 so you have some familiarity with it and how it can impact the plane you developped. As in, more that people like us who are just customers.
Here's what I've done so far but that didn't solve the issue:
- removing everything from the community folder except the plane
- try to change the flight model to legacy
- change all the assistance options one by one
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@Delta558 , another - unrelated - question.
How can I lower a bit the power output of the engine ? There is a max_rated_hp parameter in the engine.cfg file, but changing the value doesn't do anything (that I can notice). I can drop it to zero, engine power remains the same.
I tried lowering the cylinder_displacement and compression_ratio values and the power output does drop, but so does the max RPM (which I don't want, I would like the RPM to remain the same because as it has been modelled by JF, it is correct).
Thank you.
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@jrkob said in Carb heat effect is delayed:
I guess this customer won't receive the courtesy of a response.
I'm afraid this isn't an official support channel. Your best bet for ANY issues with Just Flight or Just Trains software is to contact our support team. There is a link at www.justflight.com
https://support.justflight.com/support/home
See also: https://community.justflight.com/topic/2/product-support
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The cause of the issue in the sim is unknown. Often with this game, developers have little more understanding than customers - it is not like FSX/P3D/X-Plane where we have had many years and a clearly defined 'way of doing things'. This game is not clear in either its SDK or the DevSupport channels about the flight dynamics.
Regarding the power output, there is no single factor which will work this correctly without affecting other areas. It is like a cube, each side being one of the engine tables. Shift one of them, you no longer have a cube (or in this situation, an engine that functions reasonably accurately). Even in the sims which I mentioned earlier that I consider to be more accurate / less 'gamey', there has to be a bit of 'best fit' with the engine to some extent, not that most people would notice. To be fair, MSFS is not much worse in this area. I believe the current situation is less than 100fpm overperforming on the climb rate, but I have said internally (and now here) until we start getting some answers to the questions we as Devs have asked, there is no point updating the flight dynamics only to see them changed again by the next Sim Update. If that sounds flippant, check the latest posts in this thread: https://community.justflight.com/topic/2683/pitch-jerks/133 and note that there is apparently an improvement in the behaviour. Then check the release notes, 'Planes' section (which should cover flight dynamics): https://www.flightsimulator.com/release-notes-1-27-21-0-sim-update-x-now-available/
Nothing in there which should affect the behaviour. So either changes are being made and not documented or the problem lay elsewhere, but for me as a Dev I am left wondering what the hell is going on.@jrkob said in Carb heat effect is delayed:
I guess this customer won't receive the courtesy of a response.
Apologies for that, I am not full-time at this (it's always been a sideline / hobby), my Mother is currently receiving palliative care and my spare time is spent travelling a couple of hundred miles to see her and help my Father, I also have full time work and a family to deal with so whilst I may drop onto this forum now and again and answer as best I can anything which is relevant to my area, it really is low priority for me at the moment and as Derek has said, the support channels are the best route to take.
