TBM 930 Fixes

Default Aircraft Turboprops
#1

I have come up with fixes for two of the TBM930’s issues.

To implement these fixes, edit the specified file entries to the specified values. You must edit the current entries - do not just paste these lines into the file, unless you paste over the original lines, or you will end up with duplicate lines.

The files to be edited are in this directory:

Official\OneStore\asobo-aircraft-tbm930\SimObjects\Airplanes\Asobo_TBM930

Suggest backing up the files first.

First fix: This fix will correct torque vs air density (torque will decrease during climb and increase during descent) and will also cause ITT to become limiting at higher altitudes.
Edit the TMB930’s engine.cfg file as follows:

high_n1 = 110

itt_peak_temperature = 2540

density_on_torque_table=0.000737:0.141, 0.000889:0.188, 0.001065:.241, 0.001267:.316, 0.001496:.42, 0.001755:.55, 0.002048:.72, 0.002377:.965

n1_to_shaft_torque_table = 0:0, 68:.07, 86:1.0, 110:4.7; Corrected N1 -> Shaft Torque

Second fix: This will cause the landing gear to create drag.
Edit the TBM930’s flight_model.cfg file. In the [AERODYNAMICS] section:

drag_coef_gear = 0.04700

Update: As someone pointed out, and I forgot to state, because these changes allow for a more realistic higher power setting at high altitude, fuel burn will be about 25% higher. I was unable to correct the fuel flow, so maximum range is reduced by about 25%. If this will affect how you use the TBM, then don’t apply these changes.

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TBM Lighting updates
#2

Cheers! This has quickly become my go-to for decently long flights, so I’ll try these later this evening.

#4

Awesome thanks for your efforts

#5

Installing this now. Excited to try it tomorrow. Love the TBM!

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#6

I thought of doing this, but was unsure about changing and then redistributing MS/Asobo’s files.

#7

Good point. I have taken down the link until someone can provide clarity around the distribution of the files.

#8

Check out this Fixed up C152 mod (C152X Realism Mod) , you can make something similar with your fixes. Nice and clean install without editing original files.

2 Likes
#9

Thanks for this so much better.

#10

As i said in a post above, I am not sure about the legality of modifying and then distributing MS/Asobo’s files.

#11

One thing I have noticed is that the ITT gets high really quickly with the mod, especially when taking off on grass runways, it makes getting moving without major over temps really difficult.

#12

You can set the itt_peak_temperature back to 2100, but then you will never be ITT limited at higher altitudes - as I recall, the ITT will max out at 740 at FL300.

I had to make several compromises to get things to work in all of the altitude stratum - it definitely is not perfectly realistic. I think Asobo needs to make many changes to the back end to correctly model turboprops; hopefully they will do that.

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#13

Fuel burn is off in the cruise as well. Should be able to do 300+ KN TAS at 30k with a burn close to 60GPH. I’m seeing 75 now with the mod.

#14

I should have originally stated that fuel flows will be higher at higher altitudes. I did nothing to correct fuel flow. The fuel flow seems to be controlled by a PID, and without knowing how the PID works in the back end (which is currently undocumented) I think that it will be very difficult to fix. If somebody knows how to fix the fuel flow, that would be great. If somebody knows how to make the font bigger for the torque, NG, and ITT readouts, that would also be great.

Asobo modeled the fuel flow to work with their modeling of the engine. In their model, you had to keep reducing power during climb, to keep under the torque limit, so that once you reached FL300 your power setting was waaaay too low (in their model, as I recall, with power set to the torque limit, the ITT was in the mid 5 hundreds and Ng in the mid eighties). A realistic power setting at FL300, would be setting the power for an ITT of 800 ( the maximum recommended by Daher for engine longevity) which would give an Ng of around 102. Because my changes allow for this more realistic higher power setting, but fuel flow is still modeled on an expected very low power setting, the higher power setting causes fuel flow to be too high. If you make a lot of maximum range flights, so that the increased fuel burn is a problem, then you should use the original engine.cfg values.

As I said, compromises had to be made - I put lipstick on the pig. Hopefully Asobo, who can make fixes in both the front end and back end, can, and will, make it better.

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#15

I get oscillations with my torque values now…

#16

I have not seen this. What power setting are you seeing this at? Are you exceeding the torque limit? If the torque reaches 109, over torque protection will kick in, and lower the torque. If the throttle setting is then still the same, torque will then again increase beyond the limit and torque protection will again reduce the torque, ad infinitum.

#17

Also, right now I’m FL300 100% throttle lever and 80% torque. Sound right?

#18

Well, at FL300, you should set the power based on ITT. Daher recommends not exceeding an ITT of 800 for engine longevity. So I would set the ITT to 800. This should give you an Indicated Airspeed (IAS) of about 198, which is what Daher’s tables show for a cruise power setting at FL300 (ISA 0 - standard atmosphere). The torque will be lower than Daher’s table show, but if the torque were as Daher’s table show, the airspeed would be too high - problem with Asobo’s TBM model. I set the torque values at higher altitudes so that they would give close to the specified IAS.

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#19

Thanks for the info! I need to download the POH!

#20

Hey @PositiveZero,

For reference, I wish I could help code but I’m a pilot not a coder.

The fuel burn should also drop with altitude too, the air density is much lower, less drag on the aircraft among other things. It’s kind of like the TAS going way up but the indicated airspeed being much lower. A PT-6 at 31K should be sipping fuel. Looking at the aircraft charts fuel burn at sea level is close to 90 GPH and 55 or less at FL 28 depending on ISA (temperature)

#21

@VinierCrayon721

I am not a coder either - retired Air Traffic Controller. I know that the fuel flows are too high; I was unable to correct this. See my post above about fuel flow.

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