Time for a Full PI System Reset – Current State Isn't Fit for Track Racing

Suggestions Hub Motorsport Features Car Features
1

Hey everyone,
I wanted to bring up something that’s been bothering me for a while: the current PI system just doesn’t make sense anymore, and it’s really hurting the game, especially in the open series — and honestly, I feel like it’s overdue for a complete rework and reset.

  • Some cars are way too dominant for their class, while others are basically dead picks — they just can’t compete no matter how much you tune.
  • The PI calculation heavily favors stats like top speed and launch, which might work for short sprints or Horizon-style races, but it falls apart on actual long race tracks where handling, braking, and cornering matter way more.
  • AWD cars are basically unviable because the system over-penalizes their upgrades.
  • On top of that, almost every car in the open series is running heavy gigantic 22 inch wheels because of how the PI treats them as a “free” upgrade with no real downside, which is just ridiculous.

Best example would be some Bentley Continental. You can’t make it competitive, which makes the car useless. Why do we even have a PI system if it creates useless cars?

It feels like the PI system was never really adjusted for real track racing — it’s stuck in a Horizon mindset. I really think it’s time for a clean reset: reevaluate how performance is measured, how upgrades affect PI, and make it fit proper circuit racing.

Would love to hear what you all think. How would you fix the system?

1 Like
2

I think grip means so much more or Forza and the current system doesn’t penalise you enough for running higher grip.
And too many cars have a speed rating of 1 but then go the same speeds as a car with 2 speed rating it’s ridiculous. The mx-5 is the biggest bug bearer of this concept.
I don’t think power to weight can ever work if you don’t get the stats of the cars correct in the first place.

1 Like
3

Why was it needed to move this topic to the suggestion hub? This is a discussion topic, not a suggestion. Please move it back.

4

Ok, long one.

I agree with you, the PI system feels outdated, especially in Open class, but the lack of adjustability also hurts the spec series. It’s been the case for a while and although there will always be superior cars, we understand that, some don’t even feel worth the time. Yet, they were pretty meticulously rendered and brought to the game, with little to no use outside of a one-model series. Puts a bit of the competitive aspect of the game into question.

Like I said in another thread, I tried to replicate the technical regulations of the japanese Super Taikyu (ST9 class I think basically 4 cylinder 2 liter cars) in Forza, starting with a Honda S2000. As long as you stay within certain parameters, ie age of the car, stock drivetrain, stock weight etc, you can get different cars to put out very similar lap times. Once you add AWD and turbos though, a lot flies out the window.

One aspect that I found majorly impactful is the lateral G stat. You can have ENORMOUS discrepancies in lat G from one B600 (for example) car to the other, and that’s obviously linked to adjustable aero, weight and tyre width. Forza aero above all, should come with a much larger penalty in terms of PI points,. It’s available to almost all cars with a 45kg front 91kg rear downforce which, once installed, do not impact the PI any longer, whether you run max aero or min aero.

The usual power to weight ratio system works well in the game, but it’s let down by the lateral G which seems to be out of the equation.

And then there are AWD systems. For some reason, AWD means the acceleration and aero efficiency of a MAERSK container in Forza Motorsport. To compensate for this, AWD cars usually need between 40 and 60 PI points more than 2WD cars to run the same laptimes in my experience. When you run an AWD car in B class, you’re basically running around in a B550 car against B600 cars. A nice challenge for 1%ers.

So how would I fix this? Well obviously I’m not as smart as the folks at Turn 10 so whatever I found out they did a while ago. I still believe the key lies in the lateral G stat, it should have a bigger impact on the overall PI number. If all cars have a similar PWR (power to weight ratio) and say a window of 1.20 to 1.22 lateral G at a given speed, then it should be closer.

Some cars are lighter, stiffer, more slippery etc so there will always be a META, not to mention what happens when you swap engines or add forced induction. Still, I think Turn 10 is better than this and can make more cars competitive overall.

Lastly, I believe the depth of modifications plays a part in the competitiveness or lackthereof of certain cars. We see, in circuit racing, time attack, drag racing, that there are ways to push a given chassis WAY beyond its standard limitations. Adding that may bring its lot of complications though, so a deep rework of the current system sounds more plausible.

I hope Turn 10 does work on overhauling the PI system. Time will tell.

3 Likes
5

As far as I know, the current PI system works this way: a bot driver gets your car with stock tuning applied, has to drive around some track that we don’t know the shape of, and the faster time it gets the higher your car’s performance index; that bot is not very skilled and so cars with a lot of power but low grip will get a worse time than a low powered car with lots of grip. At least this was how it used to work in older games, including Horizon 5. Perhaps the game counts different tire compounds completely inaccurately, meaning race slicks in FM are actually a lot more powerful than is deemed by the PI counter - that would explain why so many players put race tires on low class cars (E, D, C, B). What hasn’t changed, however, is the way tuning never changes the PI - it’s been like that since the first Forza Motorsport on the original Xbox. This is why, on top of physics glitches, the Porsche 550 is so dominant in the lowest classes.

That’s a physics issue. In Forza, there are no such things as brake temperature, tire deformation or unsprung mass, therefore the game cannot account for the decrease in performance with extremely heavy wheels and sidewall as thin as a sheet of paper.

We can never have a perfect PI system, some flaws will always appear. Working with these flaws to minimize them would impact user-generated content, which with the way Forza Motorsport works would mean breaking the game. The first step to improving the PI system is to make any changes made to it NOT break the whole game, and this itself is too much work.
Even GT7’s system can be exploited. I remember there was a time trial event with the mk6 Celica GT4 and the PI limit was close to stock, yet there wasn’t an upgrade ban - some people decided to apply a camshaft and an ECU upgrade, which unlocked engine power tuning. This way the car had a higher redline yet lower power than stock, but the rev range with peak power was somehow longer, which allowed those people to get times whole seconds faster than if they pushed the bone stock car to its limit!

6

Perfection would be too much to ask. Evolution? Revolution? Not so much. This is fundamentally the SAME system, exploited in the same ways.

Boils down to the dreaded “from the ground up” and the expectations that came with it.

1 Like
7

I think the system would be better if the car stats was correct in the first place.
Old cars with higher handling than modern cars is unrealistic.
Yes back in the day I’m sure they handled well but modern technologies would make newer cars far better handling.
Same with speed calculations in Forza there isn’t enough between say 1 for speed and 2 overall.

Maybe if instead of using bots to calculate P.I they use the leaderboards they have and adjust them.
They have a massive amount of data with leaderboards.
In theory we set our own p.i and bops for classes

1 Like
8

That’s a valid take. Imagine if all cars were pushed to their limits by players on the leaderboards, in stock form. Their laptimes would dictate the performance index.

That’d be quite an undertaking though, unless T10 had access to a super sophisticated Machine Learning AI like Gran Turismo Sophy.

9

Overall I would say Forza is a decent game. It is definitely fun for a weeks to months if you enjoy racing games. My biggest issues with the game are related to the PI Score balance within the classes of cars (E, D, C, B, A, S, R, P). Metas will always form overtime, and the game has been out for quite some time, but there is no reason a single car should be HEAVILY dominating the rivals leaderboards top10 on 90%+ tracks within a class or in some cases the same car across multiple classes (P550). Forza really needs to take a look at what cars are overperforming/underperforming and do a PI Score rebalancing. After doing a rebalancing of cars, they need to separate the Racing Tires’ (Hard, Medium, and Soft) impact on the PI Score. It feels to me the score is created as if you are running Racing Hard Tires. The issue this creates is Mediums and Softs becoming a huge advantage to your PI Score. You get a massive grip bonus without your score raising. This removes the possibility to trade tire grip for power (unless you are on an Oval or LeMans). Please rework and rebalance the PI system and do a full leaderboard reset on rivals afterwards! Otherwise the game is pretty good overall.

10

If it was spec series rivals then I would say yes rebalance is required. Everyone should try every car in atleast once in spec rivals for testing purposes and possible future pi rebalancing..? So t10 can see which is performing better or worse and go from there.

Open class rivals is always going to be off balance. That’s how it’s in reality. No car from past is going to compete with today’s technology advances wo some sort of light to heavy modifications.

Don’t cut back my favorite car that’s stock or fully tuned bc this or that car can’t keep up.. for example zo6 or cobra vs mini cooper stock or fully tuned. Don’t nerf my car so that piece of junk can keep up. No offense lol

11

It’s not just the p.i system I think it’s an overall system change.
I have built hundreds of cars and e.g A class some have 300-50bhp grip tunes and then other cars have more grip and have 450+bhp and there lighter than the other cars.
Don’t even get me started on awd it’s so uncompetitive it’s unbelievable they probably need about 30-40 p.i back to be in a good place.
I know turn 10 are scared of a Forza 3 awd meta again but god that was so many years ago lol.
But they are going in the right direction with the race classes so maybe this will be looked into