Ride Height Glitch Returns in GT6

[Otaliema]

I agree this ride height thing is a bit tricky. From the seasonal section tunes it's clear higher fronts are the way to run right now. To find out just how much a difference this makes to a car I'm taking my Corvette Stingray L46 350 (C3) '69 for a spin on Brands Hatch Indy course to get a variety of corners, low speed, high speed sweepers and hair pins. 5 laps per setting. I will be running stock everything exception suspension and LSD to provide a "blank" slate for the tests. Power weight will be factory stock. Oil change yes, LSD 6/9/6 Transmission 5 speed, Brakes 5/5, suspension will be set as follows all tests, springs 11.84/7.11 dampers com/ext 5/5 ARB 4/4 Tires SS, Toe/camber at 0.0/0.0. The idea is make the ride height the only variable.
Settings Grip Real, SRF off TCS0 ABS1

"factory" 135/135 53.374 understeer yes during full throttle and coasting at speeds over 100km/h. throttle rotation good under 100 km/h poor over 100 km/h

FC Default 110/110 54.413 understeer yes during coasting and high speeds. Throttle rotation good all speeds

Neutral 115/115 54.143 understeer present during coasting and at full throttle and high speeds. Throttle rotation ok all speeds

Min 75/75 53.205 understeer present during coasting at any speed. Throttle rotation excellent all speeds

Max 155/155 53.545 understeer present during throttle and coasting over 80 km/h oversteer present below 80 km/h. throttle rotation poor over 80 km/h ok under 80 km/h

Min/Max 75/155 52.730 understeer present during coasting all speeds oversteer present during throttle use. Throttle rotation poor at all speeds, it wanted to straighten the car out. These settings worked well in conjunction with each other wheel input+throttle equaled good stable rotation. The car wanted to oversteer with the wheel, the throttle wanted to make the car go in a straight line combined it provided a neutral handling car that was stable in slides and full throttle corning.

Max/Min 155/75 understeer and oversteer during coasting, oversteer during throttle input. Throttle rotation very high. The car would turn in very very well than would instantly turn to understeer because of the weight transfer. The car wanted to spin with throttle use. The combination made getting corner entry correct very important. in te turns I got it right I zipped through them like they where nothing. Most turns I spun out or understeered right into the grass.

Max/neutral 155/115 57.595 this was just a horrible set up, unstable, twitchy, understeering and unable to put the throttle to use.

There was an interest effect on the LSD during this testing the middle ground settings on the drive wheel produced predicable results. no or both wheels spinning. Max ride height produced inside wheel spin and min ride height produced outside wheel spin.

As for the throttle rotation discrepancy with the min ride height on the drive wheels I think that is due to the front end wanting to turn more with the higher nose.

 

[killerjimbag]

I don't believe that I said anything in the OP about shutting others down if they share an opinion. I just don't plan on getting in any fights over the issue. I'll test and tell the community what I find and let people find their own conclusions about how to play or if they choose to move on to another game.



Hmmmm... Stotty and CSLACR?

Yes Hami

 

[Lionheart2113]

@Motor City Hami, if the glitch is there, do you think it would be a code written across the board (general/every car) or just select cars? I'm up for helping out!

 

[Otaliema]

@Motor City Hami, if the glitch is there, do you think it would be a code written across the board (general/every car) or just select cars? I'm up for helping out!

it's defenitly not a across the board coding problem. the C3 i test had little efffect with the high front end in terms of oversteering. What I found is the higher the front the the more the snap rotation i gained. With a lower rear the more oversteer it generated when using the throttle.
The two combined provided a compleatly conterdicuary result. the car understeered like I didn't have rubber on the front wheels. But the reversed settings high tail and low nose gave a very stable car that I could lay into but it was also willing to turn.
So with this. Is is possbile they sneaked a update into the tuning model with the most recent update?
I know one quick way to find out. run @praiano63 Touring car tune. is it the same, slower or faster?
in fact i'm heading off to do that while the kiddo's are eatting lunch.

 

[donpost]

Just performed the following test:

Dino 248 GT '71 with Fully adj. suspension with ride height at default (105/105) and spring stiffness at 6.10/8.86 (double stiffness) - Old car on stilts plus double stiffness on springs should eliminate bumpstops/running out of travel from being a factor in the test.

Stage 3 Weight reduction and racing soft tyres - More grip should show up results better.

I took the car to Willow Springs short and headed for the skid pan circle thingy.

Test 1: Ride height at default of 105/105
Speed: 51mph
Balance: Understeer

Test 2: Ride height at 105F/145R
Speed: 50mph
Balance: Understeer

Test 3: Ride height at 145F/105R
Speed: n/a
Balance: Could not hold stable circle - OVERSTEER!?

Test 4: Ride height at 145F/145R
Speed: 50mph
Balance: Understeer


So RAISING the front ride height caused OVERSTEER I cannot explain that. More evidence that something is awry I guess.

 

[Lionheart2113]

it's defenitly not a across the board coding problem. the C3 i test had little efffect with the high front end in terms of oversteering. What I found is the higher the front the the more the snap rotation i gained. With a lower rear the more oversteer it generated when using the throttle.
The two combined provided a compleatly conterdicuary result. the car understeered like I didn't have rubber on the front wheels. But the reversed settings high tail and low nose gave a very stable car that I could lay into but it was also willing to turn.
So with this. Is is possbile they sneaked a update into the tuning model with the most recent update?
I know one quick way to find out. run @praiano63 Touring car tune. is it the same, slower or faster?
in fact i'm heading off to do that while the kiddo's are eatting lunch.

You're right. I'll try the touring car tomorrow morning...I'll have a few hours to test.

 

[donpost]

There was an interest effect on the LSD during this testing the middle ground settings on the drive wheel produced predicable results. no or both wheels spinning. Max ride height produced inside wheel spin and min ride height produced outside wheel spin.

I think that is expected as a lower ride height = less weight transfer = less of a traction difference between inside and outer wheel = less diff accel needed, and the outside wheel going red is usually a sign you need to lower the diff accel setting right?

Is the current theory that the ride height settings are swapped front and rear, but that a higher setting still means the car is higher off of the ground and vice versa? If so then both your observation there and the skid pan test I just did agree with that theory...

 

[Otaliema]

I think that is expected as a lower ride height = less weight transfer = less of a traction difference between inside and outer wheel = less diff accel needed, and the outside wheel going red is usually a sign you need to lower the diff accel setting right?

Is the current theory that the ride height settings are swapped front and rear, but that a higher setting still means the car is higher off of the ground and vice versa? If so then both your observation there and the skid pan test I just did agree with that theory...

The prevailing thoery is that the Higher the front end the more oversteer is generated.
I just ran 5 laps on @praiano63 FITT tune it just a snappy and stable and with in my lap time error tolerance of half a second, so no stealth patch

So based on this this information. The C3 which is a naturally understeering car was not affected by the ride height glitch or if it is I didn't find the right rear height setting to see it, so that means, it's not a univerisal code issue. Now by the theory that the settings are "swapped" in the game that means we should be able to take a oversteering car like say a elise 111R drop the nose to the ground and set the tail mid way up and have a stable drieable car. but my own experiance tuning one for the current seasonal says thats not the current fact. Most of the posted tunes including from some of the top drivers show match or nearly match ride height to stablize oversteer. My tune is the largest differance in F/R setting but is the lowest car as well.

Now somthing I shoudl have put in my testing post. I noticed the higher my nose the more likly i was to light up the outside front durring braked corner. This leads me to beleave that whats happening is the weight is transfering forward allowing the rear to swing around faster (yes i know thats the long winded way of say oversteer but hear me out), if the rear is too low there is no effect as little weight is shifted, if it's too high the understeer generated counters the oversteer thus resulting a null effect, get the front and rear at the correct seaperation the weight shifts and causes the car to rotate but only when used with the throttle. I even noticed this when testing praiano's tune again under coast it would still understeer just like all the others, but soon as I put some throttle on it, it rotated like a dream. So i don't think this is a simple lift the nose get oversteer issue.

 

[Lionheart2113]

^^^ I appreciate the way you guys are looking at it from a logical point of view trying to determine how and why it would do this in the real world. Trust me, from an engineering background I would do the same, so this is not meant to be malicious towards anyone. But to me, a glitch is just that, a glitch...there's probably no rhyme or reason what causes it except an oops on the programmer's part. In GT5 I had 2 transmission setups that were exactly the same except for first gear and they would make the car behave completely different between the two even when first gear was never used on the track(GVS). No reason for it and to this day I can't explain it, it just was. So my fear is that if you use the ride height adjustments, they might have to coincide with some other setting(s) that we wouldn't think of based on what would happen in the real world/logical. Just a thought.

 

[Otaliema]

You're right we just want to understand how it's working so we can use it, avoid it or tune around it so that when they patch the game we are not lefft high and dry per say with all of our tunes being useless.

 

[donpost]

I agree. I know I've spouted some theory but it could be totally irrelevant especially if there is a programming error. We could still try to look for patterns in the game but I'm fresh out of ideas for tests to perform except for maybe trying out more cars at the skidpan.

The worst outcome would be if we concluded that there is no rhyme or reason or pattern to it, and you basically have to turn to trial and error testing countless combinations of ride height until you find the one that "works"

 

[rams1de]

@Otaliema the Elise is a race car with aero and handles much differently to road cars. From the limited tests I've done with race cars, raising front ride height may well create lift reducing cornering grip. Lowering the front increases downforce and top speed (quite markedly) so that's probably why drivers avoided using rake.

 

[Otaliema]

very true @donpost.
I can draw a couple of conclusions from the limited testing i've done. the raising the front end affects the front and rear of the car, at least on neutral springs. Lifting the front end makes it turn in more but allows more weight to be transfered turning oversteer into understeer, because of the reduced weight on the tail it's able to rotate around faster, but it needs travel to do so. so min/max testing i was doing was in all reallity proly not the best. I'll need to go back and test more middle ground rear ends on the C3 and see what i get.

@rams1de very true but with this glitch if you get the ride height seaperation correct that reduced grip is more than compensated for with perfect rotation of the car, and snappy turn in.

 

[Thorin Cain]

Hi guys, I was just wondering what cars you have tested this with so far @Motor City Hami?

The reason I am asking is...I know what the in-game descriptions say about the differing ride heights. And I believe @DolHaus is right when he says...

my thoughts on the matter are based on my (vague) understanding of real life physics that should mean that the higher end of the car should be more susceptible to inertia due to the added leverage.
Basically when the car turns the weight is transferred up and to the outside (body roll), the higher end of the car should exert more force due to the increased leverage and therefore having the rear higher than the front should lead to increased rotation/oversteer.

So I was wondering if it could actually be more to do with the weight transfer than anything else?

The reason I suggest this and I'm probably barking up the wrong tree, is that giving the car a higher front and a lower rear will move the centre of gravity towards the rear of the car when the car is in a neutral position and even more so under acceleration, correct?

So I would expect this to have a similar effect to moving ballast towards the rear of the car, wherein a front heavy car with understeer would do so less and a tail heavy car would oversteer more. This, of course does not take the spring rates and dampers into account.

And if this is true...

Ride Height mimics real world - This is a stretch, but I can come up with one condition where this is close to a real world situation. I may need to build a video to show this using a remote controlled car, but hang with me. The in-game description says that when you lower ride height, you also shorten shock travel. So imagine a car with very long front shocks and very short rear shocks. As the car leans into the corner, the inside rear wheel will eventually reach a point with a short shock where it lifts off of the tarmac, thus leaving only one rear tire with grip. The opposite happens with a long front shock where the inside front wheel is allowed to keep a strong level of grip even with lots of weight transfer.

I would suggest that what is happening is that the front wheels of the car are turning easier due to having less weight transferred to them under braking and the rear wheels wont get to the point of lifting off as the weight will transfer back to them a lot quicker after releasing the brakes and again, even more so under acceleration. And with the long front shocks the front wheels will still have the required grip on the way out of the corner to keep the car rotating cutting down the amount of understeer

As I said, I may have the wrong end of the stick here but I am interested to hear your views on this.

 

[donpost]

Just tested 5 more cars on the skidpan:

Lotus Elise Sport 190 '11 (MR)
Jaguar XKR-S ' 11 (FR)
Renault Clio RS '11 (FF)
Mitsubishi Lancer Evo IX GSR '05 (4WD)
RUF BTR '86 (RR)

All of them acted the same way as the Dino I tested. They all reacted to ride height changes backwards. Raising the front would induce oversteer, and raising the rear would induce understeer. This was occuring in a constant speed cornering situation where longitudinal weight transfer isn't in effect.

One thing that struck me was how powerful it was for influencing the mid-corner balance of the car.

 

[Motor City Hami]

Hi guys, I was just wondering what cars you have tested this with so far @Motor City Hami?

Only two so far.

@praiano63 Mazda Roadster Touring Car https://www.gtplanet.net/forum/thre...e-one-week-to-test.303511/page-8#post-9399671
With 140/90 ride height is a full second faster than my tune.

My Mazda Roadster Touring Car https://www.gtplanet.net/forum/thre...6-miata-roadsters.291066/page-13#post-9406385
With 85/90 still has understeer. Also look at the rest of the settings, all trying to induce exit oversteer.
Springs 9.75/10.00 (followed the in-game description and saw little to no improvement)
Dampers Compression 2/6 (2 front will let the nose drop on entry, 6 rear will keep the rear from compressing on throttle)
Dampers Extension 6/3 (6 front will hold the nose down on exit, 3 rear will allow quick weight transfer for better entry)
Anti-Roll Bars 3/4 (should produce oversteer
Camber 0.0/0.3 (should produce oversteer)
Toe -0.15/-0.12 (-0.15 front should give exit oversteer and negative rear should help mid-corner rotation)
This tune cannot be spun out. It is ridiculous. I tested with super hard rear springs, super high rear sway bars, -4.5 degrees of rear camber, much higher negative toe and nothing seemed to get faster. After I saw praiano's tune, I tried different ride heights and instantly found exit rotation. I tried 140/90, 140/75 but 125/80 seemed to be enough when combined with the other aggressive settings of the tune.

I also just tuned a Lancer X Rally Car on request. I made that thing full rock solid in the rear (max rear springs, max sway bar, max weight transfer to the front, -5 rear camber) and nothing worked. As soon as I tested 140/70 ride height, I gained almost two seconds.

 

[JackWilson]

The ride height settings are exactly the same as they were in GT5.

All the tuning options, and their effects are the same. The only thing that is different is the driving physics. Which are noticeable without needed to tune anything.

PD kept to their word by updating their physics. They done that. But they didn't mention anything about updating their way of tuning.

Just my opinion

 

[DolHaus]

Hi guys, I was just wondering what cars you have tested this with so far @Motor City Hami?

The reason I am asking is...I know what the in-game descriptions say about the differing ride heights. And I believe @DolHaus is right when he says...


So I was wondering if it could actually be more to do with the weight transfer than anything else?

The reason I suggest this and I'm probably barking up the wrong tree, is that giving the car a higher front and a lower rear will move the centre of gravity towards the rear of the car when the car is in a neutral position and even more so under acceleration, correct?

So I would expect this to have a similar effect to moving ballast towards the rear of the car, wherein a front heavy car with understeer would do so less and a tail heavy car would oversteer more. This, of course does not take the spring rates and dampers into account.

And if this is true...

I would suggest that what is happening is that the front wheels of the car are turning easier due to having less weight transferred to them under braking and the rear wheels wont get to the point of lifting off as the weight will transfer back to them a lot quicker after releasing the brakes and again, even more so under acceleration. And with the long front shocks the front wheels will still have the required grip on the way out of the corner to keep the car rotating cutting down the amount of understeer

As I said, I may have the wrong end of the stick here but I am interested to hear your views on this.

That's a strong theory, makes the most logical sense so far

 

[DigitalBaka]

Whoa there big fella! I posted something and you replied,so when I have rebuttal,you don't like it? Here, go to this link and tell me the countless hours that these 2 companies put into the development of this game are actually here.
Right off of PD's own site.
http://us.gran-turismo.com/us/products/gt6/technology/

What I find most interesting is the use of the word "tyre" on a US-branded site. Copy/paste? Really?



Reading between the lines, they use the words/phrases "introduced into" and "incorporated" which to me is a fancy way of saying "we took the old stuff and added new stuff on top", not "this is totally new from the ground up". Working for a multi-billion dollar, Fortune 100 company I see this all the time. Sometimes it works, often it does not. Especially when it comes time to change and update things. It would not surprise me in the least if GT6 has only portions of the model they are working on for GT7 and the PS4s computational advancement.

If we know what each tuning lever does and we expose it to the GTPlanet community, then it levels the playing field a bit and makes the game more fun.

I hate the word "lever". See previous comment about who I work for. You sound like my Senior VP and his "pulling levers". Also the word "perspective". Buzz words and Corporate America drive me batty.

O.k. That totally contradicts your OP.

Not quite:

Now, having been around the forums for as long as I have, I know that the discussion and debate will happen right along side the true test results

Back @JLG_GT , I certainly respect you don't want to see it or deal with it as it is in no way constructive. In a global forum though, hard to have the discussion about something that isn't correct without having folks who just want to point a finger. No disrespect to anyone's comments, they all have their place somewhere, just saying that's how things are when you open up the discussion to all comers. Nothing to be done but ignore the discussion or filter the noise.

it's defenitly not a across the board coding problem. the C3 i test had little efffect with the high front end in terms of oversteering. What I found is the higher the front the the more the snap rotation i gained. With a lower rear the more oversteer it generated when using the throttle.
The two combined provided a compleatly conterdicuary result. the car understeered like I didn't have rubber on the front wheels. But the reversed settings high tail and low nose gave a very stable car that I could lay into but it was also willing to turn.
So with this. Is is possbile they sneaked a update into the tuning model with the most recent update?
I know one quick way to find out. run @praiano63 Touring car tune. is it the same, slower or faster?
in fact i'm heading off to do that while the kiddo's are eatting lunch.

You're right. I'll try the touring car tomorrow morning...I'll have a few hours to test.

Wish I had gotten to the TCs before the update to provide another perspective.

@Otaliema the Elise is a race car with aero and handles much differently to road cars. From the limited tests I've done with race cars, raising front ride height may well create lift reducing cornering grip. Lowering the front increases downforce and top speed (quite markedly) so that's probably why drivers avoided using rake.

The car that was referenced, that started this whole thread basically, is @praiano63 's Roadster TC. This car, as I'm sure you know, also has aero similar to race cars but not the pace of most, obviously. For those too lazy to click the link he is running full, or near, aero and a RH split of 140/90. Granted it's a praiano tune, but those that have tested it have found it is significantly faster than the field tuned to the same base specs on the same car. The case may be that this car is more similar to road cars than race cars but I think we can still conclude that at least not all race cars are immune to this. It could very well be something from car to car or in conjunction with other settings. Saying that an Elise or other car "handles differently" doesn't seem to be valid.

I'm intrigued now and will probably kill my Miata testing (again) and test this out with a number of Audis (notoriously nose heavy and familiar to me), maybe the AZ-1, F40, C30, C3 Vette...I'll try to find things with similar stock tires, high power, low power....yay long nights!

EDIT: tree'd by a few folks because I'm replying piecemeal at work. Whatever.

 

[Otaliema]

@DigitalBaka you don't have to worry about it, they didn't change anything on the tuning/driving phyicis of the game with this patch just added online content and updated the racing suites.

Interesting note with the racing gear. if you owned a peice prior to the patch, you get all other colors at no cost. O_O so I have 34 helemts and 34 racing suties now of two varititys

 

[Thorin Cain]

Only two so far.

@praiano63 Mazda Roadster Touring Car https://www.gtplanet.net/forum/thre...e-one-week-to-test.303511/page-8#post-9399671
With 140/90 ride height is a full second faster than my tune.

My Mazda Roadster Touring Car https://www.gtplanet.net/forum/thre...6-miata-roadsters.291066/page-13#post-9406385
With 85/90 still has understeer. Also look at the rest of the settings, all trying to induce exit oversteer.
Springs 9.75/10.00 (followed the in-game description and saw little to no improvement)
Dampers Compression 2/6 (2 front will let the nose drop on entry, 6 rear will keep the rear from compressing on throttle)
Dampers Extension 6/3 (6 front will hold the nose down on exit, 3 rear will allow quick weight transfer for better entry)
Anti-Roll Bars 3/4 (should produce oversteer
Camber 0.0/0.3 (should produce oversteer)
Toe -0.15/-0.12 (-0.15 front should give exit oversteer and negative rear should help mid-corner rotation)
This tune cannot be spun out. It is ridiculous. I tested with super hard rear springs, super high rear sway bars, -4.5 degrees of rear camber, much higher negative toe and nothing seemed to get faster. After I saw praiano's tune, I tried different ride heights and instantly found exit rotation. I tried 140/90, 140/75 but 125/80 seemed to be enough when combined with the other aggressive settings of the tune.

I also just tuned a Lancer X Rally Car on request. I made that thing full rock solid in the rear (max rear springs, max sway bar, max weight transfer to the front, -5 rear camber) and nothing worked. As soon as I tested 140/70 ride height, I gained almost two seconds.

I see where you are coming from. To put the 2 tunes side by side it really does look as if the exact opposite of what you have found would be true. I would have expected yours to rotate very well (Really nice colour combo by the way!) with the original settings and looking at @praiano63 version you would expect a lot less there. The ride height, spring rates and downforce settings he has used all look to me as if he was trying to fight the rear of the car to stop it over-rotating but obviously this is not the case.

I also guess that the opposite will be true and the very tail happy MR cars can be cured or at the very least helped along their way by having a much higher rear than front. I am not going to get a chance to try this out for myself for a couple of days but I think it is definitely worth Investigating further. I will post my results here when they are done.

 

[shaunm80]

Just tried this glitch on the Cadillac CTS-V which I have been trying to tune for ages now. I could never get it to turn smoothy. The amount of power it chucked out was making it drift round bends. Using max height at front/min height at rear, the handling has just improved 100% to something that goes round bends easily... coincidence? i think not..

https://www.gtplanet.net/forum/thre...ew-seasonal-setups.300860/page-8#post-9448918

 

[Otaliema]

I see where you are coming from. To put the 2 tunes side by side it really does look as if the exact opposite of what you have found would be true. I would have expected yours to rotate very well (Really nice colour combo by the way!) with the original settings and looking at @praiano63 version you would expect a lot less there. The ride height, spring rates and downforce settings he has used all look to me as if he was trying to fight the rear of the car to stop it over-rotating but obviously this is not the case.

I also guess that the opposite will be true and the very tail happy MR cars can be cured or at the very least helped along their way by having a much higher rear than front. I am not going to get a chance to try this out for myself for a couple of days but I think it is definitely worth Investigating further. I will post my results here when they are done.

You would think that about the Elise but looking at the seasonal tunes they are running matched ride height for the top tunes right now, so this ride height glitch is not written in the base code, it's looking like it's only a fix for A;FR cars or B; it's select cars in the game.
Personally I'm leaning to the FR answer add it seems to work very well on any FR car it's been tried on but MR/RR/FF cars seen to be immune

 

[Motor City Hami]

You would think that about the Elise but looking at the seasonal tunes they are running matched ride height for the top tunes right now, so this ride height glitch is not written in the base code, it's looking like it's only a fix for A;FR cars or B; it's select cars in the game.
Personally I'm leaning to the FR answer add it seems to work very well on any FR car it's been tried on but MR/RR/FF cars seen to be immune

I don't think that the Elise has much understeer stock? I have only tested 4WD and FR so far, but FF is likely to be the same story. For MR and RR, do these really need help turning?

 

[jules283]

I have a few thoughts which I will try to put to words..

It's not a glitch!...GT's tuning section says or used to say that changing front/rear relative ride height altered weight distribution. The GT tuning section has also said that lowering front ride height increases oversteer. This is not strictly true! Don't believe me?...then read on..

First, a note on rotation. What do people mean when they say rotation? My knowledge is that, for any given weight distribution an oversteering car will rotate mostly on corner entry by having a very precise front end that tucks-in, especially when the throttle is lifted. The rear of the car will not float much as it is pinned up against the rear tyres which will have given up some or most of their movement/deformation. Applying the throttle at this point can easily "use up" the remaining rear tyre capacity/movement and send the rear of the car into a slide.
An understeering car will display a lazy, imprecise front end as the front tyres deform during corner entry. This suggests that the rear tyres have plenty of movement/deformation still available at this point and, indeed, the rear of the car can float around a bit on corner entry, especially with rear heavy cars. Some people might think of this floaty effect as rotation. The real rotation for an understeering car is at corner exit, as, with lots of rear tyre available, the car will rotate more on power application than the oversteering car.

My knowledge/testing has shown that a car's weight distribution has to be matched with spring rate/force distribution. A rear heavy car will oversteer more, especially at the limit, but it's over/understeer tendencies can be balanced/changed with spring rate.
So, for example, a car with 60% front weight/40% rear weight may need 60% of total spring rate at front/40% spring rate rear to be balanced neutrally. If you change this spring rate distribution to 40/60 then the car balance will shift toward oversteer.
If you leave the springs at 60/40, but alter car weight distribution to 40/60 then the balance will shift toward understeer (at a new weight distribution).
So weight distribution and spring rate distribution are linked or dependent on each other.
( I will make a point soon, honestly!)
So, if you have differing front/rear ride heights then "two" changes have taken place,
1) Weight distribution.
2) Spring rate distribution (because it is no longer matched to weight dist.).
These changes produce the following effects,
1) Very high front/low rear ride height on a car that was previously set-up with neutral steer results in understeer with floaty/heavy rear with good rotation on exit and good traction.
2) High front/low rear on a car that was previously set-up with way too much oversteer results in low oversteer with precise front and no floaty rear. Very different!
3) The opposite effect of low front/high rear. Here, more oversteer is created with plenty of lift-off tuck-in. This is, I believe, why GT tuning section suggests lower front ride height increases oversteer. It does when performed in isolation without an accompanying spring rate adjustment.
Also, consider aero for a moment. Race teams match aero balance to weight distribution, with a rear heavy car requiring more rear downforce to balance out/reduce oversteer. So if, in GT6, you are tuning a car with rear aero which cannot be removed and the car has too much understeer, then one fix is to shift weight rearwards to more closely match the aero balance. If you do this by adjusting front/rear relative ride heights then you don't even need to add ballast.

I believe my above wall of text (sorry!) goes some way toward explaining the "glitch" and also explains how testing the effect of a high front/low rear ride height will show varying results which will depend on the spring rates of the car being tested.

Note: I have tested my ideas presented above, but way back in GT3 and GT4 when ballast did not exist. I would change the weight distribution with ride height and then correct the understeer with spring rates. It is very time consuming to find the correct spring rates though!

Note: The "glitch" could also be caused by the changing aero effects of tilting the car body. Or by the steeply inclined roll axis inherent in this layout. I haven't gone into any detail with these as I believe the cause to be listed above.

Another Note: I have assumed above that the effects of differing front/rear ride heights in GT are to change weight distribution, as suggested in the text of GT's own tuning section (GT3/4?). I do not believe that the higher front mass/low rear mass equates to high front weight transfer/low rear weight transfer or high front leverage/low front leverage. I have read tons of vehicle dynamics books and they typically provide an average for mass/center of gravity height in their models. My guess is that on a car with 50/50 weight distribution and a front ride height of 50 and a rear ride height of 100, that GT takes the average ride height of 75 as the basis for any weight transfer/grip multiplier calculations.

 

[DigitalBaka]

Some testing. Drove about 150 miles between the three of these. More to come as try moving just one end of the car. For each test I moved only ride height. Everything else is stock and default including the rest of the suspension. I will attach best lap replays when I have the time.

Track: Eiger Nordwand Short Track
Car: Audi S4 '98
Parts: Comfort Soft tires (stock), FC Suspension (not stock )
Settings: ABS1, DFGT, Grip Real

• Default (130/130) - 1'17.504 - Fairly neutral, handles well to be honest. Could be a crappy car to test. Some lift off oversteer, generally noticeable only in 2nd. Car is better than I thought it would be.
• Rear Rake (180/85) - 1'16.892 - First note, this looks ridiculous. Like something with a collapsed suspension. I am easily drifting every corner at Eiger. I cannot drift under normal circumstances. Braking seems worse
• Front Rake (85/180) - 1'17.562 - Looks like someone that walks down the hall looking at the ground. Definitely does not rotate as well. RR ghost consistently .7-1.0 ahead, .2 and .5 at T1 and T2 respectively. Seems to brake quicker but rear is looser under heavy braking.

For the most part I could run these three on top of each other in the 17.5 range all day. The rear rake is easy to over-rotate but hit it right and you get what I got. The others are more consistent. Front rake definitely harder to get used to but can easily lap as good as stock. The feel is definitely different even if the lap times are close.

 

[Thorin Cain]

You would think that about the Elise but looking at the seasonal tunes they are running matched ride height for the top tunes right now, so this ride height glitch is not written in the base code, it's looking like it's only a fix for A;FR cars or B; it's select cars in the game.
Personally I'm leaning to the FR answer add it seems to work very well on any FR car it's been tried on but MR/RR/FF cars seen to be immune

The Elise has superb handling in stock form and I think it displays the characteristics I would expect for a car with a rear weight bias so I am not surprised that there is no ride height difference with the top tunes. My thoughts were more to do with the more powerful MR cars where there is a large amount of lift-off oversteer, Will these cars benefit from having a higher rear/lower front? This is one of the things I am going to be testing.

As I stated in my first post and it looks as though @jules283 agrees, that this "glitch" is actually showing us that by using the extreme ride height difference we would in fact be altering the weight distribution of the car somewhat (Without the weight balance figures changing on screen however.) and as a result the weight transfer too. And I think this is why we are seeing the results that we are.
I did notice that the weight distribution on the Mazda Roadsters tuned by @Motor City Hami and @praiano63 that they both have a front weight bias and I have found, generally that in GT6 that cars with a front weight bias tend to be more likely to exhibit some understeer, cars with a 50:50 weight distribution tend to be fairly neutral and cars with a rear weight bias will display more oversteer. This is of course not a 100% rule but none the less this has been my experience with a lot of the cars I have tried in this game so far. So any way of shifting the centre of gravity of the car towards the rear will result in less understeer/more oversteer and depending on the original weight distribution of the car this may lead to better lap time performance. And I guess PD agrees with me, Has anyone else noticed the pp of a car change as you move the ballast from front to rear? and this is not new it was the same in GT5.

 

[MrGrado]

Test out ride height on the fastest tunes from the MX5 shootout. If you can't improve on them, then ride height myth Busted.

 

[Lionheart2113]

Test out ride height on the fastest tunes from the MX5 shootout. If you can't improve on them, then ride height myth Busted.

I was kinda thinking the same thing, but instead of the fastest, I was going to go after the tunes I found that seemed to struggle in the center and see if there are any differences; good or bad.

 

[MrGrado]

From the seasonal section tunes it's clear higher fronts are the way to run right now.

Do you mind linking some of these tunes? I look there and just see tunes with equal ride height and lowered front ride heights, but I haven't looked at every tune for every seasonal.

Or quote or link some evidence that shows that higher ride height works.