Throttle Notch Question (eng file)

[fwbryan]

In reading some technical material, I came across a statement that said that the horsepower produced at various throttle notches was not proportional. The percentages compute, for notches 1 thru 8: 7, 13, 24, 36, 47, 61, 79, 100%.

If this is valid (anyone know for sure across all units?) can the eng file be modified by changing the values in the following section:

EngineControllers (
Throttle ( 0 1 0.125 0
NumNotches ( 9
Notch ( 0 0 Dummy )
Notch ( 0.125 0 Dummy )
Notch ( 0.25 0 Dummy )
Notch ( 0.375 0 Dummy )
Notch ( 0.5 0 Dummy )
Notch ( 0.625 0 Dummy )
Notch ( 0.75 0 Dummy )
Notch ( 0.875 0 Dummy )
Notch ( 1 0 Dummy )

To what does the 0.125 in the second line (Throttle) refer? Increment? Must it be constant across all notch positions?

I can see where this change could make the locomotives more responsive in the lower notches, saving the big oomph for when you really need it. Percentage change from 1 to 2 is 6%, from 7 to 8 is 21%.

[plainsman]

The response to increasing throttle input varies from make to make, and even from model to model within those makes (a U33C handles this quite differently than a CW44-9). The .eng file allows a better model of this than is currently used, but it has not been adjusted yet, and particularly, it has not been calibrated to the individual models performance curve. This will take a little more time and study, maybe physics update 4.5?
Bob

[cytrain]

I think the .125 you were asking about applies to increments when there is no notching, using the mouse.

For example, in the default GP38 .eng file you will find this:

EngineControllers (
Throttle ( 0 1 0.125 0 0.
NumNotches ( 9
Notch ( 0 0 Dummy )
Notch ( 0.125 0 Dummy )
Notch ( 0.25 0 Dummy )
Notch ( 0.375 0 Dummy )
Notch ( 0.5 0 Dummy )
Notch ( 0.625 0 Dummy )
Notch ( 0.75 0 Dummy )
Notch ( 0.875 0 Dummy )
Notch ( 1 0 Dummy )
)

Note the extra 0 in the Throttle line.
The effect of this was that when you used the mouse, you had smooth control, and when you used the A & D keys you had notched control. This has also been mentioned in the Train-Sim.com FAQ.

The solution was to delete the last zero.

[jtr1962]

I already did this for a number of locomotives. For the Dash-9 I changed the following in the .eng file(changed values in bold):

Throttle ( 0 1 0.125 0
NumNotches ( 9
Notch ( 0 0 Dummy )
Notch ( 0.044 0 Dummy )
Notch ( 0.11 0 Dummy )
Notch ( 0.23 0 Dummy )
Notch ( 0.34 0 Dummy )
Notch ( 0.50 0 Dummy )
Notch ( 0.65 0 Dummy )
Notch ( 0.81 0 Dummy )
Notch ( 1 0 Dummy )
)
)


In order to get the notches to display correctly in the cab, I changed the following in the .cvf file(once again changed values in bold):

MultiStateDisplay (
Type ( CPH_DISPLAY MULTI_STATE_DISPLAY )
Position ( 264 345 34 15 )
Graphic ( ThrottleDisplayGrn.ace )
States ( 18 3 6
State (
Style ( 0 )
SwitchVal ( 0 )
)
State (
Style ( 0 )
SwitchVal ( 0.095 )
)
State (
Style ( 0 )
SwitchVal ( 0.185 )
)
State (
Style ( 0 )
SwitchVal ( 0.25 )
)
State (
Style ( 0 )
SwitchVal ( 0.34 )
)
State (
Style ( 0 )
SwitchVal ( 0.385 )
)
State (
Style ( 0 )
SwitchVal ( 0.445 )
)
State (
Style ( 0 )
SwitchVal ( 0.478 )
)
State (
Style ( 0 )
SwitchVal ( 0.5 )
)
State (
Style ( 0 )
SwitchVal ( 0.55555 )
)
State (
Style ( 0 )
SwitchVal ( 0.6111 )
)
State (
Style ( 0 )
SwitchVal ( 0.66665 )
)
State (
Style ( 0 )
SwitchVal ( 0.73 )
)
State (
Style ( 0 )
SwitchVal ( 0.77775 )
)
State (
Style ( 0 )
SwitchVal ( 0.8333 )
)
State (
Style ( 0 )
SwitchVal ( 0.88885 )
)
State (
Style ( 0 )
SwitchVal ( 0.9444 )
)
State (
Style ( 0 )
SwitchVal ( 0.99995 )
)
)
)


I used the values from Al Krug's website(look for "C44 Fuel Use & Horsepower by Throttle Position"). While probably not 100% accurate for the Dash-9, they do make it much more realistic and controllable at low speeds, and also make the maxiumum speeds in each notch when pulling a train more evenly spaced.

[cytrain]

Neat.

I can understand your editing the .eng file, but why was it necessary to edit the .cvf file? Both before and after, there are only 9 throttle positions (Idle and Run 1-8).

[kevarc]

It would be so that the HUD and the display that showes % throttle will be the same as what the eng file is.

Kevin Arceneaux

[fwbryan]

Given a different set of values for each throttle notch, what determines the values in the cvf file?

[cytrain]

Yes, that's a point. I've got so used to driving without the HUD I'd forgotten about it.

[kevarc]

When you move the throttle the cabview shows the change in the notch that it is in. You have the HUD and the little box that comes up for a couple of seconds showing percent throttle.

Kevin Arceneaux

[jtr1962]

>I can understand your editing the
>.eng file, but why was
>it necessary to edit the
>.cvf file? Both before and
>after, there are only 9
>throttle positions (Idle and Run
>1-8).

The .cvf file needs to be edited so that the graphic displays for N1 through N8 show up correctly in the cab. If this is not done, then the notch number displayed in the cab will not correspond to the actual notch you are running in. Everything will still work correctly(i.e notch 1 will be 4.4%, notch 2 11% and so on), but the indications in the cab will be incorrect.