Simviation Forum - A little more thrust

Aug 27^th, 2010 at 6:21pm

Happyapple96 Offline
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Vancouver, Canada

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I have a plane that does not have enough thrust. It rises very, Very slowly. Which entries in the Aircraft.cfg should I tweak?
Smiley

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Reply #1 - Aug 27^th, 2010 at 6:52pm

Groundbound1 Offline
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Jet or prop?

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Reply #2 - Aug 27^th, 2010 at 7:01pm

Capt.Propwash Offline
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I'm curious about this too. My Alphasim Blackhawk (HH-60), takes off very slowly. even with only 400 lbs of fuel, and 2 pilots weighing 180lbs each. total weight = 760 + whatever the aircraft weighs. With this weight, it should take off like a bat out of He.. well, you know; but it doesnt. It acts like it is at 100% fuel, with 4000 lbs cargo/PAX on board. ..... very slow.

Also, i have a couple Prop jobs that taxi by themselves at IDLE Throttle, WITH the Parking break set. (too much thrust)

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Reply #3 - Aug 28^th, 2010 at 12:30pm

Groundbound1 Offline
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No, I don't work for Mythbusters...
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I haven't messed around these things in a while, but if memory serves, these are the entries to play with.

For jets:

[TurbineEngineData]
fuel_flow_gain=       0.002
inlet_area=          20.912
rated_N2_rpm=    29920.000
static_thrust=    17400.000 <--This one
afterburner_available= 0
reverser_available= 1

For props:

(Props are a little trickier, experimentation will be needed)
[piston_engine]
power_scalar =1.000 <--This
cylinder_displacement= 85.000 <--And this
compression_ratio= 8.500
number_of_cylinders= 4
max_rated_rpm= 2500.000
max_rated_hp= 150.000
fuel_metering_type= 1
cooling_type= 0
normalized_starter_torque= 0.300
turbocharged= 0
max_design_mp= 0.000
min_design_mp= 0.000
critical_altitude= 0.000
emergency_boost_type= 0
emergency_boost_mp_offset= 0.000
emergency_boost_gain_offset= 0.000
fuel_air_auto_mixture= 0
auto_ignition= 0
max_rpm_mechanical_efficiency_scalar=1.000
idle_rpm_mechanical_efficiency_scalar=1.000
max_rpm_friction_scalar=1.000
idle_rpm_friction_scalar=1.000

[propeller]
thrust_scalar =0.878 <--This too
propeller_type= 1
propeller_diameter= 6.300
propeller_blades= 2
propeller_moi= 5.000
beta_max= 0.000
beta_min= 0.000
min_gov_rpm= 0.000
prop_tc= 0.000
gear_reduction_ratio= 1.000
fixed_pitch_beta= 20.000
low_speed_theory_limit= 80.000
prop_sync_available= 0
prop_deice_available= 0
prop_feathering_available= 0
prop_auto_feathering_available= 0
min_rpm_for_feather= 0.000
beta_feather= 0.000
power_absorbed_cf= 0.000
defeathering_accumulators_available= 0
prop_reverse_available= 0.000
minimum_on_ground_beta= 0.000
minimum_reverse_beta= 0.000

Helos:
(Never messed with these much)

[turboprop_engine]
power_scalar=50.0 <--This for more power

[propeller]
thrust_scalar=9.0 <--For more lift I think
propeller_type=1
propeller_diameter=
propeller_blades=2
propeller_moi=5.706520
beta_max=0.000000
beta_min=15.000000
min_gov_rpm=0.000000
prop_tc=0.100000
gear_reduction_ratio=1.000000
fixed_pitch_beta=20.000000
low_speed_theory_limit=80.000000
prop_sync_available=0
prop_deice_available=0
prop_feathering_available=0
prop_auto_feathering_available=0
min_rpm_for_feather=0.000000
beta_feather=0.000000
power_absorbed_cf=0.000000
defeathering_accumulators_available=0
prop_reverse_available=0
minimum_on_ground_beta=0.000000
minimum_reverse_beta=0.000000

For props with too much idle thrust, try reducing the prop thrust_scalar number.

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Reply #4 - Aug 28^th, 2010 at 3:07pm

Capt.Propwash Offline
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Let's get a little mud
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KCHS, Charleston, SC, USA

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thanks for the info. it is at least a starting point to start to look at things. Smiley

The thoughts and expressions contained in the post above are solely my own, and not necessarily those of Simviation.com, its Moderators, its Staff, its Members, or other guests. They can not, are not, and will not be held liable for any thoughts, or expressions, or posts that I have made, or will make in the future.

Computer Specs:: Acer Aspire Laptop..Win7 Home Premium 64-bit (sp1), AMD Athlon II X2 P340 (Dual Core) [2.2 Ghz], ATI Mobility Radeon HD 4250 (256mb), 4GB DDR3......FS9.1(sp3) / FSX (sp2)..... Ultimate Terrain X, Ground Environment X, REX, FTX ORBX PNW-PFJ-NRM-CRM, OZx, Tongass Fjords, Misty Moorings

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Reply #5 - Aug 28^th, 2010 at 3:43pm

Groundbound1 Offline
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No, I don't work for Mythbusters...
Michigan, USA

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Like I said, It's been a while since the last time I messed around with those settings. I'd love to give a better description of what to do, but I don't remember all the details, and would rather not say, than say wrong. Wink

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Reply #6 - Aug 28^th, 2010 at 5:16pm

aeroart Offline
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Fly the good-old good
ones: Convairs, DC-6,
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Before you start fooling around with the aircraft.cfg file, make a copy of it -- just in case!

Try increasing the values, one at a time, and see what happens. For example, if you change [thrust_scalar] from 9.0 to 10.0, change that line's values to read: 10 //9

The "//" keeps anything that follows from being used by the program, but reminds you what the last value was if you want to go back to the last setting.

Art

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Reply #7 - Aug 28^th, 2010 at 11:13pm

Capt.Propwash Offline
Colonel
Let's get a little mud
on the tires!
KCHS, Charleston, SC, USA

Gender:
Posts: 1958

way ahead of you. in fact, i have backups of the entire default AIRCRAFT folder as it was straight out the box, as well as .zip backups of EVERY aircraft, scenery, program, EVERYTHING. Cool

Never mess with computer files without the RECOVERY in place.

The thoughts and expressions contained in the post above are solely my own, and not necessarily those of Simviation.com, its Moderators, its Staff, its Members, or other guests. They can not, are not, and will not be held liable for any thoughts, or expressions, or posts that I have made, or will make in the future.

Computer Specs:: Acer Aspire Laptop..Win7 Home Premium 64-bit (sp1), AMD Athlon II X2 P340 (Dual Core) [2.2 Ghz], ATI Mobility Radeon HD 4250 (256mb), 4GB DDR3......FS9.1(sp3) / FSX (sp2)..... Ultimate Terrain X, Ground Environment X, REX, FTX ORBX PNW-PFJ-NRM-CRM, OZx, Tongass Fjords, Misty Moorings

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Reply #8 - Aug 31^st, 2010 at 9:25pm

Happyapple96 Offline
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Vancouver, Canada

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Posts: 58

Thanks for all the replies! I was on vacation, so I couldn't get back. My plane was a prop, I changed the "maximum_torque" and "static_thrust". Now it's working normally.

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