A question about the DPU smoke program.

[trainman_47]

While this is a great tool for reducing smoke output on 95% of diesel units, It seems to struggle with any and all payware BLW locomotives. Does anyone know how to stop the puffing of dark smoke on these models even with throttles closed?

[fchrist16]

If you're good with working in the engine files adjust these four lines and see what results you get. These settings are courtesy of trainman9 here on the forums.

DieselSmokeEffectInitialMagnitude( 0.5 )
DieselSmokeEffectMaxMagnitude( 2.0 )
DieselSmokeEffectInitialSmokeRate( 1.2 )
DieselSmokeEffectMaxSmokeRate( 2.0 )

Regards,

-Frank C.

[rdayt]

I haven't used the DPU program. I've always edited the .eng file.
This is what the exhaust looks like out of the box, so to speak.
Bad.JPG
Notice how the smoke is shooting way up in the sky?
This is because the exhaust opening is too small.
The opening called for in the .eng file is 0.085m. It doesnt say meters but it is, and 0.085 meters is 3.3464567 inches.
This is way to small for the volume of smoke being pushed through it.

Exhaust1
(
0.03 5.085 3.18
0 1 0
0.085
)
Exhaust2
(
0.03 5.085 3.18
0 1 0
0.085

In this picture the opening had been increased to .2 meters or 7.87402 inches.
better.JPG
The second engine hasn't been modified.

Here's how the .eng file entry looks.

Exhaust1
(
0.03 5.085 3.18
0 1 0
0.2
)
Exhaust2
(
0.03 5.085 3.18
0 1 0
0.2

Better, but we're not there yet.

Now we need to adjust the amount of smoke being shoved through the hole we just enlarged.
Down further in the .eng file we're looking at the Diesel Smoke Effect.

DieselSmokeEffectInitialMagnitude( 1.2 )
DieselSmokeEffectMaxMagnitude( 9 )
DieselSmokeEffectInitialSmokeRate( 0.5 )
DieselSmokeEffectMaxSmokeRate( 15 )

These numbers are much too big.

Here's what the numbers mean.
DieselSmokeEffectInitialMagnitude( 1.2 ) - This is basically the minimum "height" of the smoke plume.
DieselSmokeEffectMaxMagnitude( 9 ) -This is basically the maximum height of the smoke plume.
DieselSmokeEffectInitialSmokeRate( 0.5 ) -This is basically the minimum amount of smoke.
DieselSmokeEffectMaxSmokeRate( 15 ) -This is basically the maximum amount of smoke.

Let's adjust them.

DieselSmokeEffectInitialMagnitude( .2 )
DieselSmokeEffectMaxMagnitude( 2 )
DieselSmokeEffectInitialSmokeRate( .8 )
DieselSmokeEffectMaxSmokeRate( 3 )

This is what it looks like.

Betterer.JPG

We're getting there.
See where the smoke plume begins? About a half a meter above the stack?
We'll have to fix that.

Going back to the positioning text,

Exhaust1
(
0.03 5.085 3.18
0 1 0
0.2
)
Exhaust2
(
0.03 5.085 3.18
0 1 0
0.2
5.085 is the distance from the top of the rails to where the smoke is emitted. It's too high.
Let's lower it.

Exhaust1
(
0.03 4.6 3.18
0 1 0
0.2
)
Exhaust2
(
0.03 4.6 3.18
0 1 0
0.2

This is what we've done.
best.JPG

Looks much better, eh.
You'll notice that there are two exhaust entries, Exhaust1 and Exhaust2. Both exhaust streams exit the same stack at the same location. That's because this is an ALCO locomotive and I'm guessing that in order for it to show correctly in MSTS they needed to double up on the smoke.
Alcos are notorious for smoking a lot.

You can use these numbers if you like but I just spitballed them for illustration purposes.
No two locomotives are going to behave the same so fudge the numbers a little till you get what looks good to you.

Randy

[R. Steele]

complete exhaust tutorial, nice job Randy.

[rdayt]

Yeah, I see so many screenshots that would be so much better if only they would fix the exhaust.
This ain't rocket surgery.
This is my way to say something without picking on anybody.

Randy