Data Output

I too would like data out, keep this thread alive

+1 i would like that !

I think Data Output is in Forza Horizon 4 now, go into HUD and Gameplay and then scroll all the way down!

Data Output is in the game now

The SIM Dashboard Android App now supports Forza Horizon 4:

Data Output is also working in the free roam mode, so you can create additional Displays for Cruising, Drifting and a Race Display with Tire Temperatures, Turbo Pressure and so on.

Is there any documentation on the FH4 data out? I’m struggling to find anything on it.


Data output is the same structure as Forza Motorsport 7

FH4 + Motion = Great fun

Thanks, I did wonder. I’ve been told by a user that my app doesn’t work in the FM7 mode so I presumed something was different. Has the packet size changed?

I have built a shift light with an ESP8266 for Forza motorsport 7, I thought it would work with Horizon, but at the first packet received my ESP8266 crashes and reboots.
Is there a difference between Motorsport and Horizon?

The data structure is definitely different in some way - the packet is a different size for starters.

Grimbert - I’ve seen values of 66 and 67 in the gear field so this will probably be why your shift light has a meltdown! If you find any documentation, please let me know.

Forza Motorsport 7 :

  • 232 bytes in “Sled” mode
  • 311 bytes in “Car Dash” mode

Forza Horizon 4 :

  • 324 bytes

I didn’t test enough car dash to get conclusions, but “sled” data (the 232 first bytes) look the same for FM7 and FH4.
I need detailed documentation too for these structure differences. Please Turn10 / Playground, if you hear us…


It was indeed the packet size which produced the error (tried to fit 324 bytes into 311).
I got it running perfect now, only problem now is when I resume Horizon/Motorsport on my Xbox there is no data, it only works when the game is started normally, but thats probably a bug in the game itself.

It seems that the values that were added in “Car Dash” mode in FM7 were moved towards the end of the Horizon 4 packet. The structure of the Horizon packet is:
[0]-[231] FM7 Sled data (as mentioned before)
[232]-[243] FH4 new unknown data
[244]-[322] FM7 Car Dash data
[323] FH4 new unknown data

I’m using the following C# code to get a new byte array that has the same structure as a “Car Dash” packet in FM7:
if (rawTelemetryData.Length == 324)
byte newData = new byte[311];
Array.Copy(rawTelemetryData, 0, newData, 0, 232);
Array.Copy(rawTelemetryData, 244, newData, 232, 79);
rawTelemetryData = newData;

I’m not using all the available information in my program, so I’m not sure if all of this is correct.


Thank you very much indeed! This has saved me a lot of work!

One million thanks for figuring this out and documenting it! I’ve successfully used it to add experimental support for FH4’s data format to the Python Forza library I maintain so data from FH4 can be captured as well.

Would also like to second the request to have Turn 10 (or Playground Games) document the full packet format as soon as possible so we know what new data we’re getting.

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I would also like to hear from turn10 about the new data structure for fh4. Something similar to the one for the FM7 post would be great.

Props to RUBITS for posting the layout!


It would be great to get info on the Horizon packet format. A quick post on the Horizon data out structure from the devs would be very helpful.

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Active aero? Triggers for PR Stunts?

[232] represents the car type and the values of [236]-[243] are changing whenever you hit destructible objects.


Is there any possibility to ask for some new data from the developers?
I’m working on my Master Thesis and I would like to test some of my work on Forza Horizon 4.
I would like to have the current Center of Gravity position (distance from front and rear axis, and height), the actual requested Acceleration and Brake torque, and Steering wheel request, the steered wheel angle, and the current weight loads on the wheels.
Thank you

Also, does anybody know, are the accelerations measured in the center of the car, or center of gravity?