Gran Turismo 7 Physics

Do you want more detailed and realistic physics on the next GT


  • Total voters
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  • Poll closed .
I cannot compare as I did not try this car (Miata race car) before this patch. But let's hope PD stops adding understeer to its cars!
I can't confirm it but I used the same Miata for 4 hours (I had a go 1 hour before the update this morning when I got my Roulette ticket) and then I tried again after the update and switched to a different tune with RMs.
 
I can't confirm it but I used the same Miata for 4 hours (I had a go 1 hour before the update this morning when I got my Roulette ticket) and then I tried again after the update and switched to a different tune with RMs.
I think if there were really fundamental changes and ALL cars now have more understeer, then at least the drivers in sport mode will be able to confirm this in a timely manner. Many of them know their times and know where they can go and how fast. If these cars now have more understeer, it will definitely be noticeable.
 
This isn't true. The physics being realistic underneath isn't held back by the controller. A player's ability to control the car will be though, hence why assists exist, and why a layer of algorithm exists to interpret stick movement to wheel.
It may not be true in other games, but it is true with GT. It's good, it's realistic, but it's not intended to be a pure sim and likely won't ever be. It's a bit of a moot point because without looking at the game code, it's hard to tell what it's doing differently.

Take tires as an example. They've always been grip multipliers on the same basic tire model, but that's not how a tire really works. A high mileage tire (like a "comfort" tire) has a different compound and a different carcass, to provide different characteristics. They might add more sophistication in the future, but it's a tough thing for the casual player to wrap their head around, so it likely won't, especially considering that they have yet to do it. At least I haven't noticed a difference in behaviour between comfort, sport, and race tires in the game, aside from grip.

So maybe compromise is the wrong word for it. It's sim enough for me. I can apply the same methods of driving in game that I use at track days, so I'm content in general.
 
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They don't, but I suspect that this actually has nothing to do with AC's physics engine and more to do with it running at 30fps on console.
AC runs at 60fps on console. I think you are mistaken with ACC running 30fps on PS4.
Oh, and you can stress understeer all you like, your overblown claims about it have been repeatedly debunked by videos from numerous sources on both console and PC.
My main claim is the characteristic are not accurate. Cars don't simply understeer irl the way they do in AC.

With zero agreement until 1.13, and you've already demonstrated a very clear confirmation bias in that regard.
Confirmation bias from what? Some of use play the game everyday and notice the changes. A lot of the people in this thread were here only to complain and didn't bother playing after the first few days and were arguing off arm chair. It was either here or a Reddit post that people noticed undocumented changes to the physics model.
 
AC runs at 60fps on console. I think you are mistaken with ACC running 30fps on PS4.
Appologies, your correct.
My main claim is the characteristic are not accurate. Cars don't simply understeer irl the way they do in AC.
Based on what? I've direct experience of a number of them in reality and disagree.
Confirmation bias from what? Some of use play the game everyday and notice the changes. A lot of the people in this thread were here only to complain and didn't bother playing after the first few days and were arguing off arm chair. It was either here or a Reddit post that people noticed undocumented changes to the physics model.
That you believe PD are releasing magical background updates to the physics, they are not, no evidence aside from 'feels', is enough to show confirmation bias.

PD are simply not running updates to a live, running title, yet you've claimed that not only are they doing so, but that they have changed the physics as a result.
 
Suggested I share this post from the general thread here:

I'd like to share a few observations on the tyre ("tire" across the pond) model and the driving practices it elicits. Feel free to tell me I'm wrong, I've had limited experience with this game and no sim racing for a long time before that. I'm trying to test my understanding of what's going on rather than hold court. In the distant past I was a motorcycle road racer and I've previously designed the driving model for a series of driving games. While they were primarily dirt track games with vastly different parameters the fundamentals of slip angle and ratio and tyre load still apply.
I'll state from the outset that I'm enjoying the game. Force feedback in particular has come some way since I was working in the space in the late 90s and early 00s. That said, despite the updates (and I haven't driven the earlier versions) the transition from grip to slip seems excessively abrupt, even for a sim. In the mid engine cars this manifests as a sudden loss of rear traction on a trailing throttle most particularly in corner combinations. In the front engine rear drive cars it's a sudden uncorrectable spin under acceleration while the tyres are experiencing lateral turning forces. And the 4WD vehicles seem to suffer from a lesser combination of both. As for the rear engine cars, I endured the Porsche cup through the Cafe Menu system and I'm in no hurry to go back.
Without more experience or access to the internals it's difficult to determine where this is coming from. The drop in lateral force with slip angle might be excessive, it could be an excessive drop in longitudinal force with increasing slip ratio (wheelspin relative to forward velocity of the tire), an unhappy marriage of both or errors in the effect of tyre load (weight transfer) on grip coefficient. Whatever the cause, for my money the accuracy of a driving experience is most meaningfully measured by the driving behaviours that top competitors employ and it's here that GT7 is found somewhat wanting. Note that even an entirely accurate model may illicit unrealistic driving practices if real world driving cues are absent. For this reason my bias (if any) would be to make the model slightly more forgiving than reality so that drivers can still push as hard and consistently as they might in the real world. As an example when my race bike would break traction exiting a turn there would be a set of rotational motion and vibrational cues that would be absent in all but the most dedicated sim rig allowing faster response and a greater chance of saving the slide even before the engine note changed.
I've been particularly focussed on the Group 3 daily races at Red Bull Ring this week and particularly using the WRX. It seems the drivers getting into the 1:27s and 1:28s are doing some radical short shifting. 1st to 3rd etc or 2nd straight through to 4th. At first I thought there might be some odd low range torque boost they were getting in the WRX but it was only when I switched TCS from 1 to zero that I finally grokked. It's simply the surest way to get the power down without your lateral tire forces shrinking to near zero in the blink of an eye. You can get similar results by judiciously riding the throttle but given the delay in response and difficulty in gauging exactly what your throttle setting is its more reliable and just as effective to be running a higher gear. I'd thought that I wasn't losing much by running TCS at 1 and getting the physics model to behave with a little more predictability but as I gained more experience at Red Bull I realised it was cutting in on fast turns which I could otherwise take flat out. As such having it off is the best way for me to make significant improvements in my lap times but it also means I'm spinning out more frequently.
The other thing that strikes me as a little odd is the downshift of an extra gear purely for the purposes of getting the car to turn in. While a bit of turn in might be expected it's enough that you have to counter steer when you get it wrong. Once again this might be down to inaccuracies in weight transfer, tyre load to grip or excessive loss of rear lateral traction under engine braking.
 
Suggested I share this post from the general thread here:

I'd like to share a few observations on the tyre ("tire" across the pond) model and the driving practices it elicits. Feel free to tell me I'm wrong, I've had limited experience with this game and no sim racing for a long time before that. I'm trying to test my understanding of what's going on rather than hold court. In the distant past I was a motorcycle road racer and I've previously designed the driving model for a series of driving games. While they were primarily dirt track games with vastly different parameters the fundamentals of slip angle and ratio and tyre load still apply.
I'll state from the outset that I'm enjoying the game. Force feedback in particular has come some way since I was working in the space in the late 90s and early 00s. That said, despite the updates (and I haven't driven the earlier versions) the transition from grip to slip seems excessively abrupt, even for a sim. In the mid engine cars this manifests as a sudden loss of rear traction on a trailing throttle most particularly in corner combinations. In the front engine rear drive cars it's a sudden uncorrectable spin under acceleration while the tyres are experiencing lateral turning forces. And the 4WD vehicles seem to suffer from a lesser combination of both. As for the rear engine cars, I endured the Porsche cup through the Cafe Menu system and I'm in no hurry to go back.
Without more experience or access to the internals it's difficult to determine where this is coming from. The drop in lateral force with slip angle might be excessive, it could be an excessive drop in longitudinal force with increasing slip ratio (wheelspin relative to forward velocity of the tire), an unhappy marriage of both or errors in the effect of tyre load (weight transfer) on grip coefficient. Whatever the cause, for my money the accuracy of a driving experience is most meaningfully measured by the driving behaviours that top competitors employ and it's here that GT7 is found somewhat wanting. Note that even an entirely accurate model may illicit unrealistic driving practices if real world driving cues are absent. For this reason my bias (if any) would be to make the model slightly more forgiving than reality so that drivers can still push as hard and consistently as they might in the real world. As an example when my race bike would break traction exiting a turn there would be a set of rotational motion and vibrational cues that would be absent in all but the most dedicated sim rig allowing faster response and a greater chance of saving the slide even before the engine note changed.
I've been particularly focussed on the Group 3 daily races at Red Bull Ring this week and particularly using the WRX. It seems the drivers getting into the 1:27s and 1:28s are doing some radical short shifting. 1st to 3rd etc or 2nd straight through to 4th. At first I thought there might be some odd low range torque boost they were getting in the WRX but it was only when I switched TCS from 1 to zero that I finally grokked. It's simply the surest way to get the power down without your lateral tire forces shrinking to near zero in the blink of an eye. You can get similar results by judiciously riding the throttle but given the delay in response and difficulty in gauging exactly what your throttle setting is its more reliable and just as effective to be running a higher gear. I'd thought that I wasn't losing much by running TCS at 1 and getting the physics model to behave with a little more predictability but as I gained more experience at Red Bull I realised it was cutting in on fast turns which I could otherwise take flat out. As such having it off is the best way for me to make significant improvements in my lap times but it also means I'm spinning out more frequently.
The other thing that strikes me as a little odd is the downshift of an extra gear purely for the purposes of getting the car to turn in. While a bit of turn in might be expected it's enough that you have to counter steer when you get it wrong. Once again this might be down to inaccuracies in weight transfer, tyre load to grip or excessive loss of rear lateral traction under engine braking.

Lovely read. Thanks.

Have you tried other games and can compare them?
 
Lovely read. Thanks.

Have you tried other games and can compare them?
Thanks Hugo :) Currently only have the PS5 at the moment as I'm developing on Mac/mobile. I'll have to get a PC soonish though.
I downloaded Assetto Corsa last night and did some practice laps on a few different tracks and in a few different cars just then.

Stability assist off and selected the aggressive presets (lower lap times but harder to control) for each of the cars. This still leaves around 30% TCS depending on the car but I read somewhere it's a more faithful attempt to represent the actual traction control systems in the cars. I guess the critical factor will be what settings you can run in an actual race and still be competitive.
At that TCS level I was able to get into predictable slides more often than with TCS off in GT7. I was still occasionally losing it but that's not necessarily a bad thing, I'm pretty green and I was sometimes being deliberately reckless. More often a slide which went too far would result in having to back off the throttle and losing some time rather than a 180+ degree spin. With TCS off entirely though it was a debacle. Will have to see what people are using online.

Interestingly it was (unrealistically) easy to control once when you went off the track. If that's the case in actual racing I might be able to make the odd beginner's mistake without saying goodbye to the entire field.

Force feedback felt decent once I dialled in some settings for my wheel that I found online though I'm not sure yet how much feedback I'm getting on what lateral forces the tyres are generating. (I like the fact that GT7 lets me know that the front wheels are slipping and I'm going to be understeering heading into a turn.) The default settings seemed most focussed on letting me know how bumpy the track was, like driving a stylus across a vinyl record. The graphics of course are a generation behind GT7 but that's of less importance to me.
 
(I like the fact that GT7 lets me know that the front wheels are slipping and I'm going to be understeering heading into a turn.)
In RaceRoom they're proud of having a "100% physics driven FFB". I understand why. There are no artificial sensations at all.
When you start understeering, the wheel goes gradually lighter. When you understeer way too much, you can feel the tyres skidding and skipping. Even "boring" FWD race cars are super fun to drive. In GT7 however, and in ACC I'd say, there's an artificial vibration instead telling you you've gone too far.
AC I haven't tried. Maybe I'll do it in the next few days, just to understand people referencing it.

When you get a PC, try RaceRoom, if only to try out what good FFB can be like. It's free to start, and a pack with all content is 50 euro. It's a cheap alternative to iRacing. The graphics and interface is decades behind GT7 however, even though a PC costing much more than a PS5 is required.
Personally, I'd rather race in 320x240 resolution with good FFB than in 4k with the current GT7 FFB.

In GT7, I believe the physics engine is good enough to have an entirely physics driven FFB, as in RaceRoom, without artificial vibration. During 1.15, when everyone went mad, that gradual lightening of the wheel could be felt when understeering even in a Super Formula. I couldn't feel gear shifts during corners at all, if I remember correctly, and braking/acceleration was definitely felt but not anywhere near how clear it's felt in RaceRoom.
 
In RaceRoom they're proud of having a "100% physics driven FFB". I understand why. There are no artificial sensations at all.
Thanks, sounds good, will check it out when I have the hardware. A friend was telling me about RaceRoom simulating each tyre with finer detail and using multiple segments rather than the point based methods I allude to in my first post. Would be interesting to know what GT7 is actually using under the hood.
 
AC I haven't tried
As long as you switch the canned effects of, it's pure physics driven in AC as well.

Thanks, sounds good, will check it out when I have the hardware. A friend was telling me about RaceRoom simulating each tyre with finer detail and using multiple segments rather than the point based methods I allude to in my first post. Would be interesting to know what GT7 is actually using under the hood.
It's pretty much a single point model, that alone doesn't automatically damn it (AC is also single point).

Once you get a PC up and running I would also suggest giving ing RFactor 2 and AMS2 a go as well, excellent physics, tyre model and FFB in both.
 
Definitely check out LiveForSpeed. An amazing (and old) SIM that simulates:
  • tire deformation
  • temperatures on 3 segments across the tire surface, sidewall, and air
  • a real-time "forces" view that allows you to see the forces on all 4 tires as you drive.

Oh and free to try (but do support the devs if you like what you see).



TyreExplanation.jpg
 
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Hi,

After being away from GT and Sim-Driving for some years - and a Lot of experience With real Cars - I also noticed differences between GT7 and older GTs and also for certain Cars.

First - I assume they reduced the Tire Grip drastically, which you notice in nearly all right Corners. I would say - that they left Out the drastically improved Tire quality of the Last years. Sometimes I have the Feeling that they use Tires from the 80s as Base model.
I also noticed when playing around With settings - that they Changed the Impact of the Differential drastically or the "Stock" settings are totally wild. In the past - a Car was mostly driveable With Base diff settings - i Changed only a Few Details and I think IT was OK to have some fun. But in GT7 you really Need to Invest time in IT and Change a Lot. And the area from starting to over/understeer to - you cannot so anymore ist very small compared to older GTs.

And I also learned. :D maxing Out the PPs doesn't make a Car fast and easy to Drive. For me mostly the opposite ist true. But so far I am also Not very much into the Details.

But I want to agree in one Point - so far I don't yet understand the reactions to braking of the Cars completely. I have some laps - where I Break nearly exactly at the Same Point on the Track - but every 6-7 laps ... The braking length ist suddenly 5-6m longer .and the Car Starts to understeer Like a Mad Idiot. Bit as Said - I don't yet understand this really.

BR K.
 
As I've been waiting for my PC upgrade parts for the rig i fired up GT7 today before taking my rig apart. It actually made me a little sad I'm mostly saying goodbye to it after playing since the first release.

I guess i was hoping for more but it's not there for me. It's a beautiful game for what it is but my itch is still in a different spot. Especially after testing ACC on the new PC with just a single screen TV while my monitor mount is in transit.

Being top 1% with decent pace in GT and being around this stuff IRL my whole life I can see why the hardcore guys frown at GT. I don't and I'm still awestruck by the technology we can have in our home just to drive imaginary cars on the internet.

Besides physics and I don't see it mentioned too much but I can definitely sense just how different the FFB frequency is between console and PC. I could never shake the detached feeling of GT.

So yeah.. Pretty pointless post and first world gripes. Still awestruck and damn excited to step it up today though and I hope GT keeps tweaking stuff to redeem its stature.
 
It seems the drivers getting into the 1:27s and 1:28s are doing some radical short shifting. 1st to 3rd etc or 2nd straight through to 4th. At first I thought there might be some odd low range torque boost they were getting in the WRX but it was only when I switched TCS from 1 to zero that I finally grokked. It's simply the surest way to get the power down without your lateral tire forces shrinking to near zero in the blink of an eye

For me, this really highlights the issue. The tyre model is atrocious
 
I have two quick comments:


I watched a Dev Diary for the upcoming F1 game for consoles. The dev went into great detail about improvements to their game systems, how they differed from previous iterations, etc. We deserve something similar from PD, their arrogance is off-putting. They're coasting off of the strength of previous GT installments and acting like they don't owe us any sort of explanation/understanding.

I say this because a friend of mine told me to try ACC on PS5, he mentioned this months ago. To be honest, I never downloaded it because I was afraid it'd ruin GT7 for me. In a fit of frustration, I downloaded it last week and I see why folks use certain terms like "sim-cade" and say that GT isn't on the same level as other games.

I felt more feedback in my DD-Pro in 5 minutes of playing ACC, than I've ever felt in GT7. I'm not a PD fan, I'm not a ACC fan... Hell, I just got into racing back in November. I don't give a damn who wins what console war or PC war lol. I care about not feeling cheated and lied to, which is what has happened with PD/Kaz/GT7.

ACC is rough around the edges, it's lacking cars/tracks... It's a bit cumbersome. But gotdamnit, it drives so well and I want to believe
PD will get GT7 to that point but I have my doubts. I just can't wrap my head around what they've could have been doing during the development period for GT7... That's number one! I think PD forgot that this is a DRIVING SIMULATOR, not a car collecting simulator.
 
Seriously though. I assume it's a photo through a wide angle lens but even so that display is tiny and not even close to the wheel. Doesn't this guy own a sim coaching business? Shouldn't he understand the benefit of correct(ish) fov?? :confused::lol:
It's the fish eye lens on the iPhone throwing you off. It's a Samsung 32" Curved display sitting right up against the wheel base.
 
Built a Mini today to replicate my friends modified R53 S and this shed a light on some more issues with GT7s handling model.

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FWD cars just won't lift-throttle oversteer... like, at all. This is a fundamental trait of driving a properly set up FWD car. Back off on throttle to help rotation (to the point of spinning if you allow it), add throttle to stop rotation. LSD helps to pull you through the corners until understeer develops, but there is nice balance to be found in well sorted FWD cars.

The game thinks that FWD are basically RWD until front traction gives up. The car rotates a LOT on throttle 'til that point, then transitions into understeer. There is basically ZERO lift-throttle oversteer at all at any speed, which is just ridiculous. I noticed it before in the Integra R and Civic touring, but I thought that maybe I tuned it out but... nope. It just doesn't exist, and this is a basic tenant of FWD driving dynamics. This is all wrong, and if this is so broken, what else is fundamentally wrong as well?

With the Mini I tuned the diff to max braking, 50 accel, and 15 initial torque, bumped the rear sway up to 6, and still no oversteer. Then I resorted to doing something I hate and would never recommend anyone doing, putting different tires on front and rear. This led to SH on the front, and CS on the rear. Strangely, this bumped my PP up which also makes less than no sense but it did allow for more rotation, and the car became very fun to drive, but it's still not enough. It's a strange work around for something that should be a normal driving trait for any FWD car, and it felt like the CS tires have a softer carcass than the sports, because the rear became very wiggly before it ever broke traction.

Still hoping for GT7 staff to get their stuff together, but this strange handling, and my game freezing multiple times today, has left me not very optimistic.
 
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FWD cars just won't lift-throttle oversteer... like, at all. This is a fundamental trait of driving a properly set up FWD car. Back off on throttle to help rotation (to the point of spinning if you allow it), add throttle to stop rotation.

Still hoping for GT7 staff to get their stuff together, but this strange handling, and my game freezing multiple times today, has left me not very optimistic.
Correct, I noticed it too. Strange thing is that former GT titles had it right (the last being GT6).

From the other side Kaz seems to be focused on trail braking a lot in GT7. So far that a car like the Polo GTI has an exagerated handling almost like a 4x4 as soon as you touch the brakes while turning.
 
Correct, I noticed it too. Strange thing is that former GT titles had it right (the last being GT6).
GT as a series has never got FWD lift off oversteer or FWD diff behaviour right, GT7, while still poor in these regards, it's still better than any part entry.

GT does 'oh you've lifted the throttle, I might start reducing understeer in a bit', rather than giving you the ability to actually steer the car with the throttle and actually induce oversteer.


FWD diffs they just get wrong period, not a single FWD can be setup to come close to the behaviour of my I30 when cornering.

As a result, FWD Road cars, but even more so, race cars are still not right in GT.
 
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I noticed that keep stock a FF Car setup keep more lift off oversteer.
A friend of my try to emulate his 500 Abarth track day setup, and LSD too and the car lost totally the "skill" to rotate when lift off the throttle. From his experience,his setup up in real life should be more loose.. probably gt7 isn't accurate enough or at all when we tune cars setups
 
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What? Ff Cars lift off oversteer more now than on previous gt titles
GT as a series has never got FWD lift off oversteer or FWD diff behaviour right, GT7, while still poor in these regards, it's still better than any part entry.

GT does 'oh you've lifted the throttle, I might start reducing understeer in a bit', rather than giving you the ability to actually steer the car with the throttle and actually induce oversteer.
You guys made me start up GT6 again to check this out: some cars don't and others do.

No reduction in understeer at lift off: '95 Integra and Fiat Coupé Turbo
But 2 cars did react with more realism then in GT7: '10 Scirocco and '11 Clio RS (this model year is not in GT7, OK)

It gave me the occasion to make several laps on Autumn Ring Reverse, and it's worth trying as it was a magnificent feeling to be able to steer the car through the subsequent corners (especially the double left "L2 and L3", and the long follow-up of L/R corners before the last 180°). The throttle can be used to help "aiming" the Clio. On the Scirocco I rediscovered how the FFB torque gets reduced in GT6 as soon as the front wheels start to spin. I can't believe that PD "lost" this, and barely replaced it by some artificial vibrating of the steering wheel at understeer. It makes me think that they gave priority to the players with a joystick (sorry, controller).

After all it was great to drive again on Autumn Ring Reverse, let's hope it returns to GT7, along with decent physics and FFB.
 
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You guys made me start up GT6 again to check this out: some cars don't and others do.

No reduction in understeer at lift off: '95 Integra and Fiat Coupé Turbo
But 2 cars did react with more realism then in GT7: '10 Scirocco and '11 Clio RS (this model year is not in GT7, OK)

It gave me the occasion to make several laps on Autumn Ring Reverse, and it's worth trying as it was a magnificent feeling to be able to steer the car through the subsequent corners (especially the double left "L2 and L3", and the long follow-up of L/R corners before the last 180°). The throttle can be used to help "aiming" the Clio. On the Scirocco I rediscovered how the FFB torque gets reduced in GT6 as soon as the front wheels start to spin. I can't believe that PD "lost" this, and barely replaced it by some artificial vibrating of the steering wheel at understeer. It makes me think that they gave priority to the players with a joystick (sorry, controller).

After all it was great to drive again on Autumn Ring Reverse, let's hope it returns to GT7, along with decent physics and FFB.


Yes,gt6's understeer effect on ffb was good. I don't understeer too why they removed It.
And gt6 physics was good for a PS3 but gt7 Is a big step ahead
 
I've gone between AC, ACC and GT7 over the last week or so and discovered a few things:

-The Alfa Romeo 4C in GT7 feels remarkably close to AC, exhibiting similar handling characteristics with a tiny bit more oversteer. In fact it's probably fair to say that cars with little to no downforce are done quite well in GT7.

-Some cars in AC exhibit a decent amount of understeer upon corner entry compared to GT7. HOWEVER, the rotational G is much more consistent in AC and won't suddenly throw you off when you least expect it

-Some GT3 cars in GT7 lack the mechanical grip needed through slow corners. It's as if the downforce has more impact on the way a car handles then the grip offered by the springs. So if the car isn't generating enough downforce, it will struggle to maintain grip. What I notice in ACC is that the downforce and the suspension (and to an extent the tyres) work in tandem rather than fighting against each other; you won't get a sudden loss of grip if the downforce drops below a certain level.

-Adding rear grip to each car dogged by it in GT7 will not necessarily result in a more realistic experience. Some cars will become too stable and handle far better than they should (the C4 Corvette is a good example). If AC and ACC is anything to go by, the grip levels need to be reduced and balanced in a more realistic way. You should be able to keep your car under control no matter what speed you take a corner, even if the grip is low. PD need to look at how a car is balanced through a corner and change the grip curve to be less "peaky".
 
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