ACC writes MoTeC telemetry for you. You set a number of laps in the setup, drive, and the game saves a log you can open in MoTeC i2 Pro, the same software real race teams use. It is free, and Kunos ships a ready made workspace for it.
This page is the setup in six steps, then what each worksheet is for, then how I would read the traces. If you have never looked at data before, read how to use telemetry to get faster first. It covers the method. This page is the ACC tool.
How to set up MoTeC for ACC
1. Install MoTeC i2 Pro
Download i2 Pro from the software page on the MoTeC website. It is free for non professional use. Take the Pro version, not Standard, because the ACC workspace is built for Pro.
Install it, open it once, and close it. That first launch creates the folders you need in step 4.
2. Set Telemetry Laps in the car setup
In ACC, open the setup for your car and go to the electronics page. There is a line called Telemetry Laps. Set it to the number of laps you want to keep.
Two things to know:
- It is saved with the setup. A setup with Telemetry Laps at 0 logs nothing. If you load a different setup, check the value again.
- It keeps the latest laps. If you set 10 and drive 25, you get the last 10.
I would run 10 for practice. It is enough for a proper run and the files stay small.
3. Drive, then leave the session
Do your run. The log is written when the session ends, so go back to the menu before you look for the file.
The files are in:
Documents/Assetto Corsa Competizione/MoTeC
Each session gives you two files with the same name: an .ld file and an .ldx file. Keep them together. If you send a lap to a friend or a coach, send both.
4. Install the Kunos workspace
ACC creates its own MoTeC workspace the first time you drive. Copy the folder called base_ACC from:
Documents/Assetto Corsa Competizione/MoTeC/Workspaces
into:
Documents/MoTeC/i2/Workspaces
There is a shortcut. In the same ACC folder there is a file called base_ACC.i2wsp-archive. Double click it and i2 installs the workspace for you.
5. Open your log
Start i2 Pro, pick the ACC workspace, and open the .ld file from the ACC MoTeC folder. The laps of the session show up in the list. Pick your fastest lap as the main lap.
6. Overlay a second lap
Add a second lap as the overlay. It can be another lap from the same run, or a lap from a different session. Now every trace has two lines, and the gaps between the lines are your lap time.
The six worksheets
The Kunos workspace has a tab for each job. These are the six it launched with.
| Worksheet | What it shows | What I would use it for |
|---|---|---|
| Compare | Speed, RPM, gear, brake and throttle | Overlaying two laps to see where the time is. This is 80% of the value |
| Driver | The same, plus steering angle and lateral and longitudinal G | Checking your inputs: how you brake, how early you turn, how you pick up the throttle |
| Wheelspeed | The speed of each wheel, so spin and lockups show up | Seeing where traction control and ABS are working, and which wheel goes first |
| Understeer and Oversteer | A math channel that works out when the car slides at the front or the rear | Putting a number on a balance problem you already feel |
| Engine Revs | Histograms of engine revs and gear usage | Checking you are not sitting on the limiter or shifting too early |
| Suspension Histogram | Damper velocity for each wheel | Damper work, and only once everything else is sorted |
Kunos said it plainly when the feature came out: you get fewer channels than the first Assetto Corsa exported. That is on purpose. The data is close to what a real GT3 team sees, and some of what the real cars log is covered by agreements with the manufacturers. It is still more than enough to find a second.
How to read the Compare worksheet
Start here and stay here for a while. Most of the time you will ever find is on this one screen.
Put your fastest lap against your second fastest, or against a quicker driver's lap in the same car. Then go corner by corner and ask three questions, in this order.
Where do I brake? Look at where the brake trace starts on each lap. Later is faster, as long as you still make the apex.
What is my minimum speed? Look at the lowest point of the speed trace in the corner. If the reference lap is 3 km/h higher there, that speed is carried all the way down the next straight.
When am I at full throttle? Look at where the throttle trace reaches 100% and stays there. Earlier is faster, but only if it stays there. A throttle trace that goes up, drops and goes up again is slower than one that waits and goes once.
That is how a debrief with an engineer works in a real car. You do not start with dampers. You start with braking point, minimum speed, throttle. The rest of the technique is in the ACC braking guide.
What the traces tell you
| What you see in the trace | What it means | What to do |
|---|---|---|
| Your brake trace starts earlier than the reference lap | You brake too soon | Move the braking point later, one marker at a time |
| Brake trace is a square block, on and off | No trail braking, the front unloads at turn in | Peak early, then bleed the pedal off into the apex |
| Lower minimum speed in the middle of the corner | You over slow the car, or the line is too tight | Brake less, not later. Carry the speed in |
| Throttle goes on, off, on again at the exit | You picked it up before the car was ready | Wait a moment longer, then go to full throttle once |
| Steering trace is saw toothed mid corner | You are fighting understeer or catching the rear | Fix the entry first. Then look at the setup |
| Rear wheel speeds jump above the fronts on exit | Wheelspin, traction control is working hard | Smoother throttle, or one more click of TC |
| One front wheel speed drops under braking | That wheel is locking | Less brake pressure at the end of the zone, or move the bias rearward |
Using MoTeC for setup work
Only go here when your laps are consistent. If your own laps differ by half a second, the data shows your driving, not the car.
Traction and braking. The Wheelspeed worksheet shows when a rear wheel spins up or a front wheel slows down more than the others. Use it to check what traction control and ABS are doing. I explain the two TC dials in TC1 vs TC2 in ACC.
Balance. The Understeer and Oversteer worksheet puts a number on the slide. If it shows understeer in the middle of every slow corner, that is a setup direction. If it shows it in one corner only, that is you. The fixes are in the understeer and oversteer guide.
Gearing and revs. The Engine Revs histogram shows where the engine spends its time. A tall bar at the limiter means you shift late or the car is on the limiter at the end of a straight.
Dampers. The Suspension Histogram shows how fast each damper moves and how often. The shape you want is roughly even on both sides, bump and rebound. A histogram that leans hard to one side tells you that corner of the car is working more in one direction. This is the last 1% of a setup. Do not start here.
For everything on the setup screen itself, go to the ACC setup guide. For tyres, the ACC tyre pressure guide matters more than any damper click.
Mistakes I see with MoTeC
- Telemetry Laps left at 0. No file. Check it every time you load a new setup.
- Looking for the file while still in the session. Leave to the menu first.
- Comparing against an alien lap only. A lap two seconds faster than yours is different everywhere and teaches you little. Compare against your own best lap, or a driver half a second quicker.
- Changing the setup after one lap of data. One lap is noise. Look at five.
- Staring at dampers. The time is in the brake pedal and the throttle.
FAQ
How do I turn on MoTeC telemetry in ACC?
Open the car setup, go to the electronics page and set Telemetry Laps to the number of laps you want to save. ACC exports the laps on its own when you leave the session.
Where does ACC save MoTeC files?
In Documents, Assetto Corsa Competizione, MoTeC. Each session has an .ld file and an .ldx file with the same name. Keep both together.
Is MoTeC i2 Pro free?
Yes. MoTeC offers i2 Pro as a free download for non professional use. You do not need a licence to open ACC logs.
Do I need i2 Pro or i2 Standard for ACC?
i2 Pro. The Kunos workspace for ACC is made for the Pro version.
Where is the ACC MoTeC workspace?
ACC creates it in Documents, Assetto Corsa Competizione, MoTeC, Workspaces. Copy the base_ACC folder into Documents, MoTeC, i2, Workspaces, or double click the base_ACC.i2wsp-archive file.
How many telemetry laps should I set in ACC?
I would set 10 for practice. ACC keeps the most recent laps, so a long run still gives you the last 10.
Does MoTeC work with ACC on PS5 or Xbox?
No. The telemetry export writes files to the Documents folder on a PC, so MoTeC is for the PC version only.