Thruster Speed Formula - Need some data to refine please

Gerdofal

Gerdofal
Greetings All!

I almost have the thruster speed formula figured out. However, certain hull masses have less accuracy than others. In order to refine the formula, I need a bunch of data. Any help you can give would be appreciated.

Instructions:
1 - Buy a Hauler
2 - Add or change anything you like EXCEPT: Do NOT change fuel tank size, do NOT add extra fuel tanks, and do NOT add weapons that use ammo (Just in case ammo matters)
3 - Enter the total mass, total speed, and boost speed as indicated on the outfitting screen
4 - Tell which thruster you are using.

How to find the mass:
Mass is displayed as a set of three numbers on the outfitting screen. If you have followed instruction 2 above, then the correct number is the first of the three.
For example: 31.3/34.6/66.3 ... you should enter 31.3 on the form below:

https://docs.google.com/spreadsheets/d/1MtKPld0Ybm2gCjMnVBc209VjonBTX4_zJpAZeMEjkpA/edit?usp=sharing

Especially needed:
- Very high and very low masses that differ by only 0.1 T
- As many scores as possible for 2A Enhanced Performance Thrusters
- Ratings exactly at the "Optimal Mass" of engines, then additional ratings close to that mass
- Lots and lots of different masses for every thruster possible!

Thanks for all the help you can give.

Lelna

PS - I did a search for this info on the forums, but all lists of data I found were from people doing speed tests with engine pips and that won't work. If anyone has a source of data I missed, please let me know.
 
Last edited:

vizvayu

vizvayu
I'd love to contribute, but right now I have several tons of cargo for the engineers and I don't want to lose it, so I can't buy a Hauler. At least not until FD add station storage so I can store my cargo and not jettison it in space.
Sorry :(
 

Mike Evans

Designer- Elite: Dangerous
Frontier
Thruster speed is just the defined speed for the ships flight model (adjusted for pips) modified by the thruster modules multipliers. The multiplier is either the maximum strength when the total mass of the ship is equal to or lower than the minimum mass rating; optimum when the mass is equal to the optimal mass; or minimum strength when the mass is equal to the maximum mass rating (any higher and the module is not allowed to be installed). When the mass is between either the minimum and optimal or optimal and maximum mass ratings it just linearly interpolates a modifier between maximum and optimal strength or optimal and minimal strength respectively. Thus when a ship is underweight it'll have the maximum multiplier resulting in higher speeds than default. Likewise a heavy ship will have the minimum multiplier and thus a lower speed than default. A ship exactly the same weight as optimum mass rating for a module that also has an optimal multiplier of 1.0 will fly at exactly its default flight speed as defined in it's flight model.
 

Truesilver

Truesilver
Mike Evans said:
Thruster speed is just the defined speed for the ships flight model (adjusted for pips) modified by the thruster modules multipliers. The multiplier is either the maximum strength when the total mass of the ship is equal to or lower than the minimum mass rating; optimum when the mass is equal to the optimal mass; or minimum strength when the mass is equal to the maximum mass rating (any higher and the module is not allowed to be installed). When the mass is between either the minimum and optimal or optimal and maximum mass ratings it just linearly interpolates a modifier between maximum and optimal strength or optimal and minimal strength respectively. Thus when a ship is underweight it'll have the maximum multiplier resulting in higher speeds than default. Likewise a heavy ship will have the minimum multiplier and thus a lower speed than default. A ship exactly the same weight as optimum mass rating for a module that also has an optimal multiplier of 1.0 will fly at exactly its default flight speed as defined in it's flight model.
Click to expand...

Mike, thanks indeed for this.

May I ask a related question ...

Are a ship's speed and manoeuvrability values inextricably linked, so that as mass/thruster numbers change, speed and manoeuvrability will go up or down together ... or is it possible for one to to move up whilst the other moves down, or in any other way for the two to be de-coupled?

This has cropped up a bit recently with thruster mods. Some players have said that they think that a ship can be made faster yet less manoeuvrable, for example.

My (untested) expectation is that the link is inextricable but I'm sure we'd be delighted to know one way or another ...

Much obliged,

Truesilver
 

Mike Evans

Designer- Elite: Dangerous
Frontier
All numbers are affected by the multipliers equally. So if you end up with a multiplier of 1.1 then both speed and turn rates and acceleration will be affected by this number. The only exception are the new enhanced thrusters that have a slightly different set of multipliers for turn rares compared to acceleration or speed so in those cases you might end up with different multipliers for each aspect based on mass.
 

jgm

jgm
When a ship's top speed is displayed in outfitting is this with the assumption of 4 pips to engines or something else? And is there some way of seeing the "defined speed for the ships flight model" for each ship in-game?
 

Mike Evans

Designer- Elite: Dangerous
Frontier
You could easily find out the answer to your first question by observing that number and then flying the ship normally. For your second question I outlined a way of working that out above but that might not be possible in all cases. There is no in game reference for these values I'm afraid.
 

Gerdofal

Gerdofal
Mike Evans said:
You could easily find out the answer to your first question by observing that number and then flying the ship normally. For your second question I outlined a way of working that out above but that might not be possible in all cases. There is no in game reference for these values I'm afraid.
Click to expand...

Thanks for the information. I've been using linear interpolation and I'm able to get good results for most engines, but I can't for enhanced performance thrusters at all.

I have an eagle, which I think has a base speed of 240 and a base boost of 350 from my experimentation. Linear interpolation has been working fine for all normal engines, but I can't make it work at all for the 3A Enhanced Performance Thrusters.

For example, when the eagle weighs 90 (exactly the optimal mass of the thrusters), it has a speed of 300 and a boost of 434 according to the outfitter. But that would mean it's getting a multiple in the range of 1.25, where the optimal multiple for enhanced performance thrusters is listed in the interface as 1.15.

Even worse though, the mismatch between linear interpolation and the actual result gets worse as the mass of the ship gets further from optimal in both directions. From my 8% error at optimal, it gets as bad as 14% when the mass is super low.

An eagle with mass of 61 using 3A Enhanced Performance Thrusters gets a speed of 384. That's a multiple of 1.60, where the max multiple is listed as 1.37.

Are the numbers in the interface just incorrect?

Thanks!
 

Mike Evans

Designer- Elite: Dangerous
Frontier
The number are only showing one set of multipliers and mass limits. The modules themselves have three sets of multipliers and masses, one for speed, acceleration and turn rates respectively and they are different in the enhanced performance thrusters.
Code: 
LinearAccelMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.1
	MaximumMult 1.2

LinearSpeedMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.25
	MaximumMult 1.6

AngularSpeedMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.1
	MaximumMult 1.3
These are the values for the size 2 enhanced drive. The size 3 has the same multipliers, just different mass limits.
 

madbilly

M
Mike Evans said:
The number are only showing one set of multipliers and mass limits. The modules themselves have three sets of multipliers and masses, one for speed, acceleration and turn rates respectively and they are different in the enhanced performance thrusters.
Code: 
LinearAccelMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.1
	MaximumMult 1.2

LinearSpeedMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.25
	MaximumMult 1.6

AngularSpeedMassCurve
	MinimumMass 50
	OptimisedMass 60
	MaximumMass 120
	MinimumMult 0.9
	OptimalMult 1.1
	MaximumMult 1.3
These are the values for the size 2 enhanced drive. The size 3 has the same multipliers, just different mass limits.
Click to expand...
Now that IS helpful! Thanks Mike!
 

furrycat

furrycat
Well that explains a lot.

The numbers shown in outfitting are the mean average of the three multipliers, which happen to be the same for the regular thrusters.

The scaling factors to base speed I was seeing in my analysis were actually the multipliers all along. Not what was listed on the screen. Simple linear interpolation after all.

For engineer mods we need to look at the percentage change of the displayed number; even though the number is wrong the percentage applies equally to the actual multiplier. That part I had right at least.

Thanks Mike.
 

Gerdofal

Gerdofal
Mike Evans said:
The number are only showing one set of multipliers and mass limits. The modules themselves have three sets of multipliers and masses, one for speed, acceleration and turn rates respectively and they are different in the enhanced performance thrusters.
Code: 
LinearAccelMassCurve
    MinimumMass 50
    OptimisedMass 60
    MaximumMass 120
    MinimumMult 0.9
    OptimalMult 1.1
    MaximumMult 1.2

LinearSpeedMassCurve
    MinimumMass 50
    OptimisedMass 60
    MaximumMass 120
    MinimumMult 0.9
    OptimalMult 1.25
    MaximumMult 1.6

AngularSpeedMassCurve
    MinimumMass 50
    OptimisedMass 60
    MaximumMass 120
    MinimumMult 0.9
    OptimalMult 1.1
    MaximumMult 1.3
These are the values for the size 2 enhanced drive. The size 3 has the same multipliers, just different mass limits.
Click to expand...

Wow! Thanks for the awesome info!
 

taleden

taleden
Mike Evans said:
Thruster speed is just the defined speed for the ships flight model (adjusted for pips) modified by the thruster modules multipliers. The multiplier is either the maximum strength when the total mass of the ship is equal to or lower than the minimum mass rating; optimum when the mass is equal to the optimal mass; or minimum strength when the mass is equal to the maximum mass rating (any higher and the module is not allowed to be installed). When the mass is between either the minimum and optimal or optimal and maximum mass ratings it just linearly interpolates a modifier between maximum and optimal strength or optimal and minimal strength respectively. Thus when a ship is underweight it'll have the maximum multiplier resulting in higher speeds than default. Likewise a heavy ship will have the minimum multiplier and thus a lower speed than default. A ship exactly the same weight as optimum mass rating for a module that also has an optimal multiplier of 1.0 will fly at exactly its default flight speed as defined in it's flight model.
Click to expand...
Thanks Mike, however I can't get this description to match actual in-game measurements. For example, here is the observed top speed (at 4 pips) of an Imperial Courier with a class 3 Enhanced Thruster, at 10T mass increments which are all between the thruster's optimum (90T) and maximum (200T):

170T = 252m/s
160T = 253m/s (-10T = +1m/s)
150T = 255m/s (-10T = +2m/s)
140T = 260m/s (-10T = +5m/s)
130T = 267m/s (-10T = +7m/s)
120T = 278m/s (-10T = +11m/s)
110T = 295m/s (-10T = +17m/s)
100T = 318m/s (-10T = +23m/s)

As you can see, each 10T linear reduction in mass yields a very clearly non-linear increase in top speed. Can you clarify how these results are possible if the multiplier is linearly interpolated for masses between optimum and maximum?
 
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Gerdofal

Gerdofal
taleden said:
Thanks Mike, however I can't get this description to match actual in-game measurements. For example, here is the observed top speed (at 4 pips) of an Imperial Courier with a class 3 Enhanced Thruster, at 10T mass increments which are all between the thruster's optimum (90T) and maximum (200T):

170T = 252m/s
160T = 253m/s (-10T = +1m/s)
150T = 255m/s (-10T = +2m/s)
140T = 260m/s (-10T = +5m/s)
130T = 267m/s (-10T = +7m/s)
120T = 278m/s (-10T = +11m/s)
110T = 295m/s (-10T = +17m/s)
100T = 318m/s (-10T = +23m/s)

As you can see, each 10T linear reduction in mass yields a very clearly non-linear increase in top speed. Can you clarify how these results are possible if the multiplier is linearly interpolated for masses between optimum and maximum?
Click to expand...

I agree, the formula starts to break down at the optimal mass. Speeds for ships with masses above that mass are not accurate for enhanced thrusters, but lower masses appear to be.

(Though, I must add, with a small sample size like I have it may be round-off error)
 
Last edited:

taleden

taleden
Actually the curve is still not linear even for masses below optimal. For the same Imperial Courier with class 3 Enhanced thrusters, here are the observed (4 pip) speeds:

90T = 350m/s
85T = 370m/s (-5T = +20m/s)
80T = 393m/s (-5T = +23m/s)
75T = 419m/s (-5T = +26m/s)
70T = 448m/s (-5T = +29m/s)
 

jgm

jgm
taleden said:
Actually the curve is still not linear even for masses below optimal. For the same Imperial Courier with class 3 Enhanced thrusters, here are the observed (4 pip) speeds:

90T = 350m/s
85T = 370m/s (-5T = +20m/s)
80T = 393m/s (-5T = +23m/s)
75T = 419m/s (-5T = +26m/s)
70T = 448m/s (-5T = +29m/s)
Click to expand...

Is it linear when you make the mass relative i.e. mass/optimal mass rather than optimal mass - mass?
 
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