Technical data Resources (Engines and gearboxes)

[TurboJ]

@rookie_one Awesome work. Absolutely essential stuff for any engine modder out there (and for many, many more!) Thank you for taking the effort and also thanks to everyone else who have contributed!

[rookie_one]

No problems

[TurboJ]

Here's a useful comparison chart for your ETS2 engine mod project. If you're editing or making new engines on original SCS trucks, you may wish to compare your torque curve to that of the original, vanilla curve. Now you can.

According to the SCS modding wiki, the default torque curve has seven data points for which multipliers are set. Both the rpm numbers and multipliers are the same on all trucks that don't have a specific, unique torque curve assigned to them. In these cases the only thing that changes between different engines is the maximum torque value itself. In practice this means the engines on "older trucks" use the default curve, while "newer trucks" use unique curves. "Older" and "newer" referring to their respective release dates as having been introduced into ETS2.


This is the default torque curve (default multiplier in clauses):

Code: Select all

300 rpm     (0)  
440 rpm     (0.5)
1000 rpm    (1)
1300 rpm    (1)
1900 rpm    (0.77)
2400 rpm    (0.4)
2600 rpm    (0)

The given maximum torque value is multiplied by these values for each rpm point. Thus your actual torque curve depends entirely on the maximum torque value and these data points.

For all torque curves, the torque values themselves are linearly interpolated between the set data points. This means on a default curve, it's always a straight line between 0-300, 300-440, 440-1000 etc.

But if you want to see how your custom curve compares to the vanilla default curve, you need to see more than just these seven data points (only five of those are actually variables as 300 rpm and 2600 rpm are always zero points).

So I made a chart which shows us the vanilla default torque curve for each 50 rpm of the effective range (in basic terms, I made the interpolation visible per rpm).

Here you go! (scroll down for full chart)

Code: Select all

rpm     tq.multiplier
				
300     0		*
350     0.167		
400     0.333
450     0.500		* 
500     0.545
550     0.591
600     0.636
650     0.682
700     0.728
750     0.773
800     0.818
850     0.864
900     0.908
950     0.955
1000    1		*
1050    1
1100    1
1150    1
1200    1
1250    1
1300    1		*
1350    0.981
1400    0.962
1450    0.942
1500    0.923
1550    0.904
1600    0.885
1650    0.866
1700    0.847
1750    0.828
1800    0.808
1850    0.789
1900    0.770		*
1950    0.733
2000    0.696
2050    0.659
2100    0.622
2150    0.585
2200    0.548
2250    0.511
2300    0.474
2350    0.437
2400    0.400		*
2450    0.300
2500    0.200
2550    0.100
2600    0		*

(asterisks show the rpm points which are directly derived from the default curve data - all the other data is based on interpolation between these given default points.
Also note: In the chart 440 rpm point has been allocated to 450 rpm for simplicity.)

Feel free to use this data how you see fit. Hope it helps.

[TurboJ]

Continuing on the subject.

Here's what the default torque curve looks like as an actual graph (example here is an engine with 1300 Nm maximum torque)

[ external image ]
(Note that the 440 rpm point is visually missing here due to the chart resolution being on a 100 rpm-step scale)


...and since POWER is directly calculated from TORQUE and RPM, then the two graphs together will always have this shape on a default curve:

[ external image ]



...and for further clarity, here's the default power graph on its own:

[ external image ]


So, as we can see, engines that utilize the default torque curve always make their maximum torque between 1000 and 1300 rpm, and maximum power at 1900 rpm. Worth noting is if you're making a custom engine, this is the curve it will use unless you give it a unique one - remembering that the end result will also rely on the maximum torque value you set for the engine.

This data and these graphs are here to make it easier to compare your own work to the base game functionality. If you ever feel like you need to adjust your custom curve to more closely meet the default curve (or vice versa), you now have the exact values and the visual shapes available for your eyes to see.

[TurboJ]

Been doing a lot of research lately. Also browsing through a lot of the materials on the 1st page link - very very useful database!

However, I can't seem to find sub-1000 rpm torque data for PACCAR Euro5 engines, or for any Scania engines (Euro5-Euro6). There are torque curves available starting from 1000 rpm, but that's only half the story - so maybe someone can point me to the right direction for finding this data somewhere?

[galimim]

Welcome to my modding life they are nonexistent, or at least not available to the public..

[TurboJ]

@galimim Thanks, lol I knew when I started my project that research would be tough, but I didn't anticipate the info being this well hidden

It figures that you haven't found the aforementioned data either, as it seems the companies in question do not like to publish such data. The curves they do show are also more than a little 'approximate'.

But I guess the positive flip side is that using weighted data from comparable engines to fill in the gaps should not be too far from the truth, given how close some of the other brands' competing engines are to each other.
And FWIW there's a limit to what amount of difference the player is able to even feel, so there's that too.

But using stuff like compression ratio, bore x stroke ratio, injection system type, turbocharger type etc. as guidelines works OK for me. It's just surprising this data isn't available as it should be a big selling point to know how well any given truck is able to get a heavy load moving from a standstill. But then again, the start-from-standstill functionality in ETS2 is something else again, so maybe we're not losing THAT much here...

[galimim]

The graphs you can find are usually just for promotional purposes, so it makes sense that they make them shiny and pretty.

Usually you dont really do start stop in a truck so the values below 900rpm don't really matter. Plus people really care only about peak torque and power (I like Scania cos 730Hp brigade), only nerd like you and me are interested in real numbers

[TurboJ]

@galimim lol

Only just now saw your reply - but I get what you say. I know people like you and me are few. And in my case it's probably a good thing

Those low rpm figures aren't super important, but they do play one crucial role. They show the effect of engine displacement on idle torque. And even though the peak numbers are what interest most people, it does matter IRL if you have 800 or 1500 nm of torque at idle (typical 8-liter vs a typical 16-liter). While the stop-start driving is maybe limited, it is always easier to haul stuff when it's easier to get moving in the first place.

Anyway, at this point I feel like I have enough base data to be able to calculate approximates for the missing torque info; and although far from perfect, this does seem to work pretty well so far in simulation terms.

* * * * *

Onto another subject. I am taking many variables into account when doing the baseline and engine tuning calculations. So little details matter to me.

Some notions:

1. From some of the French datasheets of the current-gen MAN (on the Google Drive as linked in 1st post), it seems they mention "double turbo" on almost all of their bigger 6-cylinder E6 engines. This of course usually refers to some form of turbo compounding. But can someone confirm if MAN indeed now use turbo compounding as a standard feature across their heavy truck range?

2. I'm currently working on Volvo engines, and one detail I cannot see published anywhere is what type of turbochargers they use. From pictures it would seem that both D13 and D16 had fixed geometry turbos in the Euro5 era. With the D13b I see one mention of moving onto VGT technology. Also, pictures of some of the later D13 and D16 engines clearly show the electronic actuator "box" fitted onto the turbo, meaning they're using electronically controlled variable turbine geometry. But can anyone confirm which engines have fixed and which ones VGT turbos? I know this may seem trivial, but concerning my mod simulation efforts, this is something I need to know. The base game engines would be enough, knowing their turbo type.

3. Does anyone know of a source of torque curves for older truck engines? It would be interesting for comparative purposes to see what kind of numbers the old 18 liter Merc and Iveco engines were putting out, for example. And also how much change there's been within the same engine families, like how the Scania v8 or the Volvo F16-FH16 engines have progressed through the years.

[TurboJ]

Back on the subject of Volvo engines;

The vanilla ETS2 features four D13C engine variants for the Volvo FH 2012 (plus one D13K variant).

The emission compliance standard for these vanilla D13C engines are:

*D13C420 - Euro 5 / EEV
*D13C460 - Euro 5 / EEV
*D13C500 - Euro 5 / EEV
*D13C540 - Euro 5
*D13K460 - Euro 6

...on the Google Drive database the D13C460 and D13C500 engines' data sheets are featured in Euro 5 standard only.

So here are links to data sheets with the EEV versions of these two engines:

http://productinfo.vtc.volvo.se/files/p ... 953367.pdf
http://productinfo.vtc.volvo.se/files/p ... 953370.pdf

@rookie_one ...perhaps you might wish to add these to the database? I didn't check how much difference there really is compared to the regular Euro 5 ones, but at least these are the official sheets for the vanilla engines as they are portrayed in the game.

P.S. The picture on the sheet showing the D13C EEV engine looks like there might be an electronically controlled VGT turbo on it (however real life pictures vary...)