Forza Motorsport and Horizon: UDP telemetry guide

Are you struggling to develop the perfect tunings for your races? Are you not sure where you're losing lap time? Forza Motorsport 7 and Forza Horizon 4 both support UDP telemetry.

Here's a quick guide to what is this and how can we make use of it.

What is UDP?

Put simply, UDP transmits all the information about your inputs, your car's behaviour, and the situation of the race you're competing in. You can receive this on another device, or for the PC racers, you can save this data on that machine.

This can give you the answers you need if you're struggling with your tunings or to nail that braking zone!

User Datagram Protocol, or UDP, is an internet protocol similar to Transmission Control Protocol, or TCP.

TCP is used when error checking is more critical than absolute speed, such as when you're downloading files from the internet. Web pages need error correction to make sure everything renders correctly in the browser. Other downloaded files need robust error checking to ensure the file isn't corrupted.

UDP is used when timeliness is more important than receiving perfect data. For example, making a VoIP call or joining a video chat. It's better to keep latency low and not worry too much about the odd dropped packet in these circumstances. It's the same with telemetry from your racing games: the occasional dropped packet isn't a disaster but your data needs to be in sync with your playing.

What telemetry data is provided?

Both Forza Horizon 4 and Forza Motorsport 7 transmit all of your driving inputs. This means you can log your positions on the brake and throttle, your clutch and wheel inputs.

The information goes much further than this though. This thread on the Forza Motorsport forum goes into a lot more detail of everything the game reports over UDP.

This works just as well on the Xbox as it does on PC, so everyone can enjoy looking at the data from their Forza racing!

What can I learn from telemetry?

Data can explain where you're losing time in a corner. Maybe you're not braking late enough and you're coming off of the brakes and then reapplying them. Maybe you're not applying the throttle smoothly on the exit, losing traction. Just identifying these problems with your driving is the first step to fixing bad habits!

For Forza Horizon 4, it can be tricky to learn the manual with clutch shifting while you're racing. How about setting up a live dashboard to flash the screen when it's time to upshift? This can also help when you're learning to drift.

How can I use telemetry from my games?

Developers have created a range of apps to examine your race data.

For Android users, SIM Dashboard is one of the most straightforward ways to get started with UDP telemetry. I personally use this app for both Forza Motorsport 7 and Forza Horizon 4. It's easy to build and modify dashboards to your liking, with all the widgets you'll need and some great pre-made community dashboards.

Many well-known players use SIM Dashboard. Whether to keep an eye on important numbers and make sure they're in the right gear or just to look stylish on your desk, it's a popular tool. For example, Youtuber Xpertgamingtech always has his Android phone visible in his videos:

For the more technically able player, there are a range of projects on Github you can build to record your data and look back over it.

What else can UDP telemetry be used for?

Going beyond just dashboards and recording telemetry, people have used the UDP feature to build actual hardware! This can be anything from Arduino or Raspberry Pi powered LED displays to full-on sim rigs with motorised seats for feedback.

While this is a deep rabbit hole to go down, some players find they can use this technology to improve and enhance their gaming experience.