Understanding the A.I. Physics of Forza 7

Can someone explain to me how the physics work in Forza 7?
Do the car models use it based on 4 wheels (tires) making contact with the track?
Is it based on a car model that has one wheel, in the center of the car, making contact with the track?
In which case, the car is modeled (what we see) with 4 wheels (tires) making contact with the ground.

I ask this question because I find, after the update, that the AI is faster on the straights and around corners. Before the update they were just faster in the straights.
It appears I’ve reached the limit on my xbox controller and cannot keep up with the “improved” AI cars.

Therefore, I need an understanding how the physics in this game is actually working…Is it based on 4 point system or 1 point system making contact with the track?

For human players, it is based on 4 tires. You can confirm this by viewing telemetry during a race or replay.

Only T10 knows the physics used for AI. It’s debatable whether any physics are used for AI at all.


Yes, I can actually believe that’s debatable. What I find interesting, and miss, is rubberbanding. I know, I know, folk complained about that kind of AI behavior in the past with other motorsport games but I would have thought that it would be present here. At least I’m use to it once you pass the lead car that had as much as 800’ lead. But every time I pass the lead car it slow’s down…considerably. Where I can get as much as 1000’ ahead. Even if I’m 2 seconds slower.

Another point of interest is that when you are behind a the lead car by nearly 1000’ I’m not sure it’s reflected on the lap time. At the end of the race they all show, for example:
1.44.XXX best laps. When I know if I had a best lap of 1.41.XX and the lead car was somewhere north of 500’ ahead it’s not adding up. In other words I was in second place when I had my fastest lap time. My slowest laps was 2.xx seconds behind my best lap. And my best lap was in the 3rd lap of 10. It took me 6 laps to catch the lead car and pass it. That lead AI car should have had a best lap of 1.3X.XX. Hmm…2017 Acura NSX FE on Sonoma Raceway.

Wow, can only agree with this. I would also add that if you are in 1st place that’s when the AI get’s more aggressive at higher difficulties. You would never trail AI by more then 100’ on the straights, if that.

Yes, it’s a “feature”. That’s how they program the AI for the F7. With a pad, so far, I can get up to expert. If I understand this correctly if you use a no name gamepad (as I use an xbox GP) and have to using the Input Options instead of the Controller Option. Under Advance you will now have the option to adjust Steering Linearity. If set properly should allow you to get into the corners sooner, closer to the apex, at higher speeds. I would love to compare to what the xbox controller uses but those options aren’t made available.

4 points are calculated as can be seen in telemetry and in the way temp builds on locked or sliding tires. Tuning affects the wheel and tire telemetry so everything points to them crunching the numbers on all four corners.

The way Forza steps up the difficulty (pro, unbeatable and so on) is to give the AI a scaled performance advantage (AI isn’t a driver, it’s a car) and this advantage is very much more apparent at some tracks. Are you struggling everywhere or only at certain locations? I’ve not noticed a change in the AI myself.

Depending on division this “scaling” is done by more horsepowers. Caterham blows by me on Track Toys, can never catch it. It’s slow in corners but way too fast on straights. :frowning:

Telemetry shows 367 bhp max for Caterham and Exige, max for division is 350. I was driving KTM.

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Nothing has changed. Just tune up your cars properly and learn tracks. And don’t drive with an automatic transmission.
And physics is based on 4 tyres for players and AI as well. There are other problems with physics in FM7 but that’s a discussion for another topic :stuck_out_tongue:

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I think the issue with AI performance, times, and power is that difficulty changes the lap times set by the cars, period. If that means that Difficulty X in Class Y on Track Z means they want lap times of 1:42 to 1:44, that’s what they get, whatever it takes to get those numbers.

I don’t know if it actually worked as I suspected in the 360 games, but back then I at least felt like their performance was based on what their car could actually do, and then their pace adjusted by AI difficulty. I feel like that’s less the case now, but I would like for it to work that way. I want the game calculating what they’re doing with their cars just as it does with the player, and the AI’s actually behavior and skill then based on difficulty. If it was up to me, lower difficulty AI would simply be more conservative in corners, more cautious applying throttle exiting corners, braking earlier for corners, and maybe making more mistakes like locking up brakes or getting loose because they got too eager with the gas, and then all that behavior gets worked through vehicle physics just like if a player was doing it. Then the lap times would be a result of all those behaviors and physics calculations rather than simply working towards a lap time.


The update stopped AI cars flying off the track on higher difficulties so the devs probably tidied up how they behave. If you look carefully they turn in a very simplified brake gas brake gas brake gas kind of way and their cars sort of rotate around the corner a bit like scalextric. They have simplified physics thats for sure but they do sometimes make mistakes and over/understeer.

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Quite a simple explanation really, the AI runs as fast as the game tells them to with no such concerns as physics. I play on unbeatable with a controller, can and do run top 50-100 in most career mode events, and on several random occasions the AI decides it’s appropriate to run times in the top 10.

So whenever the game coding decides it doesn’t want the player to win, you just simply won’t. They’ll brake later, turn faster in the corners, accelerate out sooner/faster, and reach a higher top speed. Nothing like watching yourself get out-dragged by the #007 Aston when you’re in a Lambo Super Trofeo AND drafting behind it as well.

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I know what you mean. As a matter of fact…the way you put it is exactly why I took the time to create this thread. The physics for my car don’t allow me to navigate the course like the AI.
I wanted to get a honest understanding of what I’m experiencing so I can understand how to play the game. But after reading your post, as well as others, it’s very clear to me that we are not suppose to have to same physics as the AI cars.

I can live with that to be honest if that’s the case. However the level of confusion I have/had while playing is what lead me to ask…

Can someone tell me what this anomaly is I’m seeing in the undercarriage of the AI car in front of me? I’ve only seen it on night maps at a certain distance behind AI cars.
It’s like something is sticking from the undercarriage to the ground.

Example 1.

2nd view.

3rd view of same car in front of me.

As I get closer to the car this is what the car really looks like.

Another AI Car.

I cant see anything abnormal.

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Here you go:

I have the exact same issue (I’m assuming, that everybody has it). It started happening after the latest update (or the one before that). I think it is just T10 way to reduce the polygon count on the screen (similar to liveries popping out and in depending of your distance of other cars). I’m sure there are better and not so obvious to eyes ways to do it.

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I figured I wasn’t the only one seeing this. This and the actual behavior of the AI racing around the track is what had me to ask:

"Do the car models use is based on 4 wheels (tires) making contact with the track?
Is it based on a car model that has one wheel, in the center of the car, making contact with the track?
In which case, the car is modeled (what we see) with 4 wheels (tires) making contact with the ground."

Since you can see the AI telemetry for all 4 individual wheels, it has all 4 individual wheels on the track

Just looks like the gap between the light beams.

For those that play on unbeatable does the AI slow down the last 2 or so laps left in the race?

Back when replays included Timing information (I have absolutely no idea why Turn-10 removed that), it was easy to see the AI cars’ lap-times.

Now, you probably have to grab a stop-watch and do the timing for yourself.

But, to answer your question, I’ve never seen them “slow down”.


By the way…

I wouldn’t look at in-exact video rendering as evidence of “physics”. It is very possible - likely, even - that fewer rendering resources are used for the AI cars.

But as far as the actual physics calculations go, what gets rendered to the screen is the result of the physics calcs, not the other way around.


There is no AI .
They are pre-programmed on rails cars.
They have zero spatial or player awareness save a script now and then.
This is why they are the worst AI ever encountered in racing.
It is lazy rubberbanding tripe that is quite frankly lazy in the extreme.
The only time you can fool the AI is when you blip them into a wall or tyres.
If you race and dodge the cars you see the simple pre-programmed patterns.
Patterns - not intelligence or even remote awareness of your car,
Complete and utter garbage.

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If they have no awareness of me being on the track why, on a straight bit of road, with the AI being in a faster car than me, will they brake/slow down if i block their path from overtaking?
Also ive witnessed the AI make plenty of mistakes with no intervention. Hell you can see it in this video I made, Drivatar in 4th hits the barrier: