Is this according to the 915iS engine?
According to the video the green line doesnāt seem to end at 240km/h.
Anyway i found this:
On page 34 it says:
VNE: 184kts
Cruise speeds at 9500ft: 50%/60%/90% 148kt/157kt/178kts
So, iās suggest to do this approach:
[AIRSPEED]
min = 0
lowLimit = 22
white_start = 30
white_end = 65
green_start = 40
green_end = 185
yellow_start = 185
yellow_end = 229
red_start = 0
red_end = 0
highLimit = 230
max = 299
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Difficult to find the right ones. According to https://www.vl3aircraft.com/ (there is a close-up vid of the Garmin), yellow starts at 250kph (135kts).
Think it al also depend which is programmed in the G3X. Also the 915 iS version is just out, so the most screenshots.movies will be from the preceding model 912 or 914.
According the Flyer Magazine: āMax speed in turbulent air is up from 135 to 150ktā
So i āconcludeā
- yellow arc starts at 135 kts (250 km/h) on 912/914 (end at 170 kts)
- yellow arc start at 150 kts (278 km/h) on 915 (ends at 184 kts).
Marcel
Ok Iām lost with all these updates. Is there any file updated with all the tweaks ? Thanks for the amazing job guys !
Sounds good to me! By the way, is there anyway to disable the warning sound of the G3X, or modify when it begin to sound? It begins at the moment I reach 205 KTAS. Would be good set it at 207.
Hey, i will resume you what to replace in the different files from https://github.com/r9r-dev/fs2020-vl3-rotax915:
Engines.cfg:
fuel_flow_scalar = 0.78
power_scalar = 1.1 ;
cylinder_displacement = 20.6 ; Cubic inches per cylinder
compression_ratio = 8.3 ; Compression ratio
min_cruise_rpm = 1800
critical_altitude = 25000 ;
max_rpm_mechanical_efficiency_scalar = 0.96
BestPowerSpecificFuelConsumption = 0.42
fuel_press_max = 5832
thrust_scalar = 2.2 ; Propeller thrust scalar
gear_reduction_ratio = 2.43
Cockpit.cfg
[AIRSPEED]
min = 0
lowLimit = 22
white_start = 30
white_end = 65
green_start = 40
green_end = 150
yellow_start = 150
yellow_end = 184
red_start = 184
red_end = 229
highLimit = 230
max = 299
Flight_model.cfg
max_gross_weight = 1690 ; Empty weight, (LBS)
empty_weight = 794 ; Empty weight, (LBS)
pitch_stability = 0.3
roll_stability = 0.3
yaw_stability = 0.3
[AIRPLANE_GEOMETRY]
wing_area = 105.5 ; Wing area S (SQUARE FEET) > GOTGRAVEL: 105.2 to 105.5
htail_area = 18.19 ; Horizontal tail area (SQUARE FEET) > GOTGRAVEL: 14 to 18.19
htail_span = 8.79 ; Horizontal tail span (FEET) > GOTGRAVEL: 8 to 8.79
vtail_area = 9.43 ; Vertical tail area (SQUARE FEET) > GOTGRAVEL: 13 to 9.43
fuselage_length = 20.34 ; Nose to tail (FEET) > GOTGRAVEL: 20 to 20.34
fuselage_diameter = 3.77 > GOTGRAVEL: 3.4 to 3.77
elevator_area = 7.86 ; Elevator area (SQUARE FEET) > GOTGRAVEL: 7.16 to 7.86
aileron_area = 2.23 ; Elevator area (SQUARE FEET) > GOTGRAVEL: 7.04 to 2.23
rudder_area = 3.33 ; Elevator area (SQUARE FEET) > GOTGRAVEL: 10 to 3.33
[FLIGHT_TUNING]
aileron_effectiveness = 1.4 > GOTGRAVEL: 1 to 1.4
[REFERENCE SPEEDS]
cruise_speed = 205; Knots True (KTAS)
max_indicated_speed = 232; Red line (KIAS)
airspeed_indicator_max = 299
climb_speed = 22 ; Climb speed (Kts)
best_angle_climb_speed = 21.72 ; Best angle climb speed (Kts)
best_glide = 65 ; Best Glide (Kts) > GOTGRAVEL: 0 to 65
Anyway, we are just testing on the go, but the plane looks so much better and fun in general
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Just be sure what conversions you are usingā¦a lot of the videos show kmh IAS vs our sim shows Knots IAS.
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Yes we are accurately calculating, converting units of measurements as needed. Also referencing source material making sure itās the 915iS. Unfortunately we cannot find the POH for the 915iS yet, so itās a bit of Sherlock Holmes work atm 
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Kudos to the smarter people who have edited this. I donāt have a consolidated file anymoreā¦I lost track of all the changes ha.
edit: Ok I grabbed the post from @CodenameJack447 just above, edited the three files, and zipped it here. Anyone can do whatever with theseā¦make them go into the new github linkā¦etc. I modified the original Nanor VL3 915 mod.
The only change I did NOT make was climb speed and best angle climb speedā¦thereās no way its 22 knots. Itās probably more like 60 knots or so.
Vx = best angle
Vy = best climb speed in their files (best rate of climb)
Please note Vx is always slower than Vy
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Since I love the VL-3 so much, I have spend the last day finding, implementing, converting and calculating any relevant factory data from JMB and Rotax, further refining the fantastic work done by @ryanbatc, @CodenameJack447, @Garfield9910, @PongRaider (and more probably).
Awesome work guys! Thanks to you the VL-3 915iS is here 
After the latest tweaks the plane behaves even more realistic (it no longer can reach FL500 for example, but still takes off like a Hot Rodā¦hehe), and I was able to remove some scalars due to this.
I am sure however there is still room for improvement (I am not an engineer nor a pilot) so keep it coming guys! Just compiling and sharing what could be found. Get the latest VL-3 915iS package below. Turns your VL-3 into the 141HP ultra-lightweight fun-machine it was designed to be!
https://mega.nz/file/pP4SQDbS#tYLREJGHNyYmUS9I-26i0j-dOjhaDiDHrCzz6lpIlmE
@Gotgravel, are you sure about this?
compression_ratio = 3.5 ; Compression ratio > GOTGRAVEL 8.3:1 to 3.5:1
According to Wikipedia, The turbocharger has a compression ratio of 3.5:1, yes but that setting is the engine compression ratio which has to be 8.3:1, according to some webpages like this https://www.kitplanes.com/more-rotax-915is/
Definitely open for discussion / research, I just implemented the number I found. Guess I understood this number wrongā¦ Should I revert? Iāll be happy to adjust, fix the zip, and publish.
No worries, in fact, i was looking where to put the 3.5:1 Value for the turbocharger but thereās no many options apart of turborcharger options and mannifold pressure.
Yes Itās not easy ā¦
But we are doing a good job!
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Hello
Thank you @GotGravel for your much appreciated help! Together we will manage to make the VL3 a rocket but which respects the criteria of the real original engines.
I appreciate the initiative to have created a new mod based on the Rotax 915 but wouldnāt it be smarter to improve the version available on github? If we multiply the mods, people will get lost in it. Then, everything will be a matter of consensus.
So I took the liberty of analyzing your work.
There is already a first difference on the AIRSPEED gauge.
Our:
[AIRSPEED]
min = 0
lowLimit = 22
white_start = 22
white_end = 66
green_start = 43
green_end = 129
yellow_start = 129
yellow_end = 156
red_start = 156
red_end = 183
highLimit = 194
max = 199
Yours:
[AIRSPEED]
min = 0
lowLimit = 22
white_start = 30
white_end = 65
green_start = 40
green_end = 150
yellow_start = 150
yellow_end = 184
red_start = 184
red_end = 229
highLimit = 230
max = 300
Would it be possible to know on what criteria these changes were made? Iām aware that this makes things clearer in the cockpit but it seems to me that they donāt correspond to reality. But I could be wrong!
For other differences:
General Engine Data
fuel_flow_scalar decreased from 0.82 to 0.78
Any reason for this ?
Piston Engine
power_scalar decreased from 1.8 to 1.0
Will probably solve the handbrake issue ?
compression_ratio decreased from 11 to 3.5
I guess it should be 8.3 instead but I admit 11 is wrong
min_cruise_rpm increased from 1400 to 1800
I guess you got this value from the operatorās manual ?
critical altitude decreased from 18000 to 15000
I guess this value is wrong. Rotax 915 turbocharger provide the max manifold pressure at 15000 feets:
but JMB Aircraftes indicates ābest performance at FL180ā:
max_rpm_mechanical_efficiency_scalar increased from 0.92 to 1
Any reason for this?
BestPowerSpecificFuelConsumption decreased from 0.49 to 0.42
Any reason for this?
fuel_press_max increased from 2376 to 5832
Operatorās manual:
Max fuel pressure is 45 psi (6480 psf), so 2376 is probably wrong but I donāt see where you get that 5832 value.
Propeller
thrust_scalar increased from 1.3 to 2.2
Any reason for this ?
propeller_diameter decreased from 6.1352 to 5.71
According to propeller caracteristics
The maximum diameter for this propeller is 1700mm (5.58 feets) so we are probably wrong but I donāt see where you got that 5.71.
Airplane Geometry
You also changed a lot of data from the AIRPLANE_GEOMETRY section. Is it normal ? Are thoose values not from the original game and should be totaly true or Asobo made mistakes ?
Did you get theses values from this document ? http://www.vliegclubmoorsele.be/docs/VL3/POH-VL-3B-3%20sn%20VL-3-71.pdf
Flight Tuning
aileron_effectiveness increased from 1 to 1.8
Any reason for this?
Reference Speeds
Same as before, lots of data changed but here, your looks A LOT more accurate. Thanks
Thanks
According to your changes, I Improved the mod from github here : https://github.com/r9r-dev/fs2020-vl3-rotax915 and added you to credits in the README. Please confirm that you are okay with that
Thanks for your help.
1 Like
Hi @PongRaiderā¦wow that is a lot of detail! Really appreciate this. I probably wonāt be able to answer all your questions since a lot of my data came from several sources, I did not keep track of it during the process. Other data came from other people.
Also, my apologies if I caused any confusion, that was not my intend. Guess I got carried away improving the flight model
All the stuff I did was based on the VL-3 315iS, that is for sure.
- compression ratio for the engine is 8.3ā¦11 was the old engine. 3.5 Was an error, that is the compression ratio for the turbo.
- power_scalar on 1 resolve the handbrake issue yes.
- speeds come from several references, but I am quite sure mine are correct (based on the numbers I found)
- critical altitudeā¦there are several numbers lingering around (15000, 18000, even 23000), but 15000 seems to create realistic performance. I could be wrong of course, never flew the plane for real. If set to 18000, the plane can obtain an FL that is just way too high (I could reach FL500)
- several scalars set to 1 as scalars are multipliers for tweaking. Some were no longer needed when more factory data was entered elsewhere in the configs.
- propeller_diameter came from KW-31 data I found > Flyer Magazine September 2020 by Flyer Digital Team - Issuu page 34
- The Airplane_Geometry received a lot of correction as a fair bit was simply incorrect. I got most from http://www.vliegclubmoorsele.be/docs/VL3/POH-VL-3B-3%20sn%20VL-3-71.pdf (which is a previous model VL-3 but the frame appears to be the same). Asobo seemed to have a lot of wrong numbers here! (aileron surfaces were totally of).
- aileron_effectiveness. The plane just seemed to roll too slow, and after watching videos, I tweaked this number to make it feel more like the observed flights. Again, this may need further tweaking
- wing dihedral changed from 5 to 7. Calculated from measurements from the POH using an atan2 function and measuring the x and y components. It just seemed too lowā¦and it was.
Would definitely be good to work on a common versionā¦never used GitHub beforeā¦now created an accountā¦will work with you guys there from now on. 
Again, really appreciate your analysis and for already updating most changes on GitHub.
Cheers mate
1 Like
Some of the engine changes are mine, so let me explain:
fuel_flow_scalar decreased from 0.82 to 0.78
BestPowerSpecificFuelConsumption decreased from 0.49 to 0.42
We are trying to achieve 9g/h max consuption at 205Ktas at FL18 according to reality and the videos provided so those values helps, but still needs more test to find accurate values. In additon, being turbocharged means reduced consumption compared to an atmospheric.
max_rpm_mechanical_efficiency_scalar increased from 0.92 to 1
It should be 0.92
fuel_press_max increased from 2376 to 5832
Iād have to find the source but i swear i read it somewhere
power_scalar decreased from 1.8 to 1.0
thrust_scalar increased from 1.3 to 2.2
Yea, decrease power scalar fix the issue, but at 1.3 trust scalar the plane looks stock in power. So, increase the trust scalar somehow adds the combined power from engine and turbo (since thereās no turbo options to set for example de 3.5:1 compression ratio). Also, we are trying to raise a max cruise of 205kts with a max of 229ktas according to this: āAfter more than 100 hours of flight test with two planes, we manage with success to perform V-dive test reaching 381km/h IAS and 425km/h TAS, this enable us to safely increase our VNE up to 340km/h IAS." Anyway, i think 2.0 thrust scalar should be fine to not over exceed 229.
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