Ride Height Bug in Gran Turismo 7

[Gumdrifter]

Let me start the thread by saying this: Gran Turismo 7's physics as of Update 1.20 feel amazing. Whether it's racing against other drivers or drifting around Tsukuba Circuit, I love the new physics... even if some cars such as the 2019 Audi R8 LMS Evo are a bit understeery now, but a couple setup changes should do the job. However, despite there being improvements to the physics, a nasty bug is still around and in my opinion holds GT7 back from having a potentially better driving experience, and that is the ride height bug.

What is the ride height bug?
First, we gotta learn the benefits of a lower ride height. In real life racing and other racing games (Gran Turismo SPORT, Automobilista 2, rFactor 2), lowering the ride height of a vehicle lowers the center of gravity, which means you'll get better overall handling and grip. Of course, you don't want to go too low or else your car will bottom out and suffer from tire rub, but generally - lower is better.

In Gran Turismo 7 however, ride height adjustments appear to be reversed. What I mean is that lowering the ride height actually reduces grip while raising it improves it, which shouldn't be the case at all. Raising the ride height should make you go slower since there'll be more lateral weight transfer and a higher center of gravity, but because ride height adjustments are bugged, one of the ways to maximize grip on a car is by lifting it.

This bug has remained in Gran Turismo 7 ever since its release on March 4th, 2022, which means we've gone through months without Polyphony attempting to fix it. It's not even mentioned on the Known Issues page that can be found on gran-turismo.com: Known Issues

This bug has been reported by fellow GTPlanet user ItsLlamaLlama on another thread and a YouTube video, though I don't think they're getting the attention that they deserve: Bugged Ride Height, Improve Handling GT7 Ride Height Bugged? Tuning and Game Physics Video

I've also made a video about the bug myself (Gran Turismo 7's Ride Height Bug | #granturismo7). In order to further support my claim that this bug is still around even in Update 1.20, I've included a few videos of me driving the Chevrolet Corvette (C2) with different ride heights and another user encountering the bug:







This is undeniable proof that having a higher ride height results in the car feeling more planted and having better overall grip throughout the lap. It's a little disappointing that this bug hasn't been fixed since March, but maybe if this thread gets enough attention, Polyphony could take note of it and finally fix it in a future update. The question is... will they actually listen?

 

[Hekler_55]

Great writeup , thanks for sharing.

 

[madmyk]

This is great, but you don't mention that PP still lowers when you raise the ride height which means you can take that PP and apply it to more HP. To me, that's what unbalances the game.

The other thing is bug applies mostly to road cars. Once you have ground effects and high downforce in race cars and some high end road cars, you don't see the same ride height benefit. That and the range is limited on race cars so you can't raise it too high anyway. For 800pp race cars and up, the meta I have seen seems to be min front, max rear height, min front downforce, max rear downforce. This setup lowers PP to enable higher HP, and handles well enough to make the extra HP worth it.

I use ride height to get more HP in my tunes, but I didn't keep testing to see if handling keeps improving. It seemed more like it's not a negative to raise ride height than an improvement, but I guess I'm not that clever.

 

[Gumdrifter]

This is great, but you don't mention that PP still lowers when you raise the ride height which means you can take that PP and apply it to more HP. To me, that's what unbalances the game.

The other thing is bug applies mostly to road cars. Once you have ground effects and high downforce in race cars and some high end road cars, you don't see the same ride height benefit. That and the range is limited on race cars so you can't raise it too high anyway. For 800pp race cars and up, the meta I have seen seems to be min front, max rear height, min front downforce, max rear downforce. This setup lowers PP to enable higher HP, and handles well enough to make the extra HP worth it.

I use ride height to get more HP in my tunes, but I didn't keep testing to see if handling keeps improving. It seemed more like it's not a negative to raise ride height than an improvement, but I guess I'm not that clever.

Hey there! I completely agree with all of your points. I forgot to mention that raising the ride height lowers your PP, so my apologies for that. (>_<)

And yeah, on race cars and some high-end road cars, the ride height bug doesn't really make that much of a presence.

 

[MarrGuitar]

Great videos, they demonstrate the problem clearly.

After the recent update the racing cars feel better than before but I’m still having issues with crazy snap oversteer on some of my tuned road cars. Even lower powered ones. Guess what? They’re all running low ride height. And after raising the ride height, it’s clear to see that it adds significant levels of grip

I hope PD fixes this. It’s an obvious problem but it seems it has been there from the start so I won’t be holding my breath

 

[wheelhp]

I'd wager some money on that weird suspension label called natural frequency having something to do with it.
In the manual for GT7 they say when tuning, natural frequency shouldn't be confused for spring rates, since it's completely different. Means they're likely using something else instead of typical vehicle physics-based spring rates to keep the car upright. Hence bugs. Since it was the same thing in GT Sport, and we did have a similar bug there

 

[gkgamer]

I'd wager some money on that weird suspension label called natural frequency having something to do with it.
In the manual for GT7 they say when tuning, natural frequency shouldn't be confused for spring rates, since it's completely different. Means they're likely using something else instead of typical vehicle physics-based spring rates to keep the car upright. Hence bugs. Since it was the same thing in GT Sport, and we did have a similar bug there

There was the reverse rake ride height in GT6 that would drastically improve rotation if I 'member right.

 

[wheelhp]

There was the reverse rake ride height in GT6 that would drastically improve rotation if I 'member right.

Yeah I remember something like that in GT6 too, would give cars higher top speed somehow, GT6 also had the camber bug

 

[Monkdapunk]

I think the frequency relates to what kind of tires you are using. Tires with more grip can utilize more frequency. I'm not sure what it really is but if I put racing tires on a car I'll turn it up to 3.3 like it says to in the description. I'm assuming it's the overall stiffness of the suspension? Idk. Look in Beyond the Apex in the game at the menu. It has diagrams and explanations of all the tuning aspects. More than the tuning menu.

 

[danardif1]

I'd wager some money on that weird suspension label called natural frequency having something to do with it.
In the manual for GT7 they say when tuning, natural frequency shouldn't be confused for spring rates, since it's completely different. Means they're likely using something else instead of typical vehicle physics-based spring rates to keep the car upright. Hence bugs. Since it was the same thing in GT Sport, and we did have a similar bug there

Natural Frequency isn't exactly the spring rate, but an expression of the spring rate combined with the mass of the car on that particular end or corner of the car. Higher NF figures do still mean stiffer springs but it's more about the relative figure from front to back and what the weight distribution of the car in question.

For example, a 1000kg car with 50-50 weight distribution and NF figures of 3.5 for front and back will have the same spring rates front and back. A similarly heavy car with 45-55 weight distribution will need a lower NF figure at the rear to have a matching spring rate to the front, because there is now more mass over that axle.