Suspension bug

[adeadsnipermatt]

Ok I have this issue that I wanted to bring up due to difficulty having tuning some cars. This may not be a bug but I have a theory I need help solving. Right now if you look at some of the time trails replays you can see some people running there car with their ride height reverse with there front set height and rear set low on fwd cars. I know for a fact this is the worst possible thing you can do to a fwd car. So I tested it out.

I took a FTO out for a spin and tuned it for around hp did a stage Weight reduction. I tuned it like a regulr car and i got a lot of understeer with it. Tht was expected but i went and reversed my ride height settings and magicaly the car felt so much better and drove faster. I dont want to hear from people you dont know how to tune etc. I know how but after testing this out it make me wonder why are people compensating their oversteer so heavly with their dampers and swaybars. It starting to make sense if you look at your ride height settings. If you do believe me just take your favorite car and reverse the ride height youll see a difference.

 

[JackWilson]

Ride high meaning ride hight right?

 

[blaktek]

I think it's due to a shortcut in the downforce programming. In GT5, downforce seems to be applied perpendicularly to the car's body. So if you raise the front and lower the back, this force is actually pushing the car slightly forward.

Maybe PD will see this and fix the thing. Maybe.

 

[Rotary Junkie]

Ok I have this issue that I wanted to bring up due to difficulty having tuning some cars. This may not be a bug but I have a theory I need help solving. Right now if you look at some of the time trails replays you can see some people running there car with their ride height reverse with there front set height and rear set low on fwd cars. I know for a fact this is the worst possible thing you can do to a fwd car. So I tested it out.

I took a FTO out for a spin and tuned it for around hp did a stage Weight reduction. I tuned it like a regulr car and i got a lot of understeer with it. Tht was expected but i went and reversed my ride height settings and magicaly the car felt so much better and drove faster. I dont want to hear from people you dont know how to tune etc. I know how but after testing this out it make me wonder why are people compensating their oversteer so heavly with their dampers and swaybars. It starting to make sense if you look at your ride height settings. If you do believe me just take your favorite car and reverse the ride height youll see a difference.

Raising the nose helps entry quite a lot in nose-heavy cars but does sliiiiiiiightly hurt exit (overstresses rear tires in R/AWD, nukes inside front traction a bit on FWD/AWD). Conversely, raising the rear will help keep the tail in check on exit with RWDs under throttle (less stress on the outside rear, albeit with less traction for the inside rear) and keep the inside front from lighting up so easily in a FWD/AWD.

 

[adeadsnipermatt]

I understand completely but I was running with a lotus Elise last night and I know that car was rear heavy I was running it nose high and the car felt like a dream. I really want some help looking into this I know the tuning mechanics I need help testing the theory.

 

[BlueShift]

If you speak french I'll explain, this is too hard to explain in english.

It's about moments of forces. Higher rh mean higher moments.

Under turnng, even if SR is recalculated to match your former setup, you'll have more moment of force, therefor, faster left to rigth weigth transfer.

RH : high/low mean left/rigth transfer hight/low to but a grippy rear. Result is oversteer, which is compensated from your SR that most ppl don't recalculate (because they don't have true RH info) so without recalculating it's transform into understeer.
The opposite with low/high.

Now this only for the handling. Front train gripping is increased for low/high and rear train gripping is raised for high/low.

And changing natural moments of forces distribution of the car implies properties of sliding changes a lot too.

 

[Slurm]

I don't want to sound cynical but... This is just another in a long list of bugs, some of which have been around since GT4. But now it's impossible to ignore because the online GT community is huge, and we can see ghosts of the fastest people in the world and race each other. Throughout millions of people, some will uncover these things and exploit them. There's also evidence that damper extension scale is backwards. Basically, this is not an accurate simulation.

 

[budious]

There's also evidence that damper extension scale is backwards. Basically, this is not an accurate simulation.

Would it blow your mind to learn damper extension is fastest at 1 and slowest at 10 but not for the reasons people think? Basically, bound and rebound are being treated as two bi-directional dampers strapped on top of one another, both are at their lowest setting (thus fastest compression, and extension) when set to 1; both are at their lowest setting (thus slowest compression, and extension) when set to 10. Neither setting is uni-directional! Stacking an extension setting of 6 with a compression setting of 6 is the equivalent of a single damper (bi-directional) stack set to 12 out of a possible range from 2-20! Thus, the higher the lower you set the extension the faster you wheels will bound and rebound, or you can set the bound to lowest setting with a maximum extension and get nearly the same result. Test it for yourself, it's nuts.

 

[nomis3613]

@OP: Just a thought: are you perhaps running soft front springs and need the extra travel to stay off the bump stops?

 

[adeadsnipermatt]

I have been tuning my cars for the past few days with the reversed ride height setting with shone surprising results. On most of my FF tunes I have been able to run a higher front rode height to induce oversteer on throttle and for my MR tunes I have been running a weird maxed rear max front ride height. With that I was about to bring in some understeer to reduce the twitchiness. The best car with this theory is the McLaren MPC4. So I still want to know are these settings really reversed or am I finally learning weight transfer physics?

 

[budious]

Weight transfer at positive ride height tuning is definitely noticeable but primarily beneficial for use with lower grade tires, which were you using? You can set up some high powered cars to run pretty decent lap times on Comfort Soft and Sport Hard if you adjust the height and other suspension settings just right.

 

[adeadsnipermatt]

I'm running racing softs online and the low front helps with the MPC and high front help my FTO

 

[Slurm]

Would it blow your mind to learn damper extension is fastest at 1 and slowest at 10 but not for the reasons people think?

(-)-Rebound--------------------Bound----
-------------------------------------------- fast end of the spectrum
(1)-------10------------------------1------
(2)--------9------------------------2------
(3)--------8------------------------3------
(4)--------7------------------------4------
(5)--------6------------------------5------
(6)--------5------------------------6------
(7)--------4------------------------7------
(8)--------3------------------------8------
(9)--------2------------------------9------
(10)-------1-----------------------10-----
-------------------------------------------- slow end of the spectrum

Personally I have always seen 1 as fast and 10 as slow, for both. It makes sense - a little resistance allows a spring to move faster.

At the time I posted my comment in this thread, I had just read the info in your above topic, and I believed you. The number of people agreeing looked as though you were in the process of proving it. But....

It turns out you were just another confused person making authoritative claims and confusing everyone else, including me. So don't talk about "blowing my mind", I will be trusting my own common-sense from now on and taking what I read here with a pinch of salt.

 

[budious]

The only thing that changed was my opinion that the system even has a polarity, the suspension physics in this game are the equivalent of standing on a bridge and throwing an object into the air and having it travel upwards at a constant rate of predictable velocity and for gravity to be completely a non-factor or even to change the objects trajectory and have the object fall back towards you. While you're there, drop another object off the bridge and watch it fall at a constant rate as though there was gravity.

Damper strength is relative to spring rate, so having a relatively weak spring attached to low damper is fast, having a stronger spring attached to a high damper is perceived as being relatively fast... the last version of that chart was updated to include a combined damper value column that has the fast rebound with the slow bound paired in rows that can be used to arrive at a constant cumulative sum. I have been testing that last published theory extensively across multiple cars and for the most part the rule of thumb can be used with good results.

So was I a little premature in making my claim? Yes. However, I think it still provided a good recourse for public discussion and eventually evolved into a somewhat different theory that attempted to reconcile all the observed differences into one model.

 

[FULL_THROTTLE]

Personally, I've always tuned cars with higher front end then rear, it just feels better (started as a cosmetic thing), the re-tune I just did to my Zonda R (not posted yet) shows this, although did not know about the bound/rebound thing, I normally just set that to what ever makes the car handle well. Will apply to this car (cause it handles like trash when its totally stock with over 900bhp)

 

[nomis3613]

I'm beginning to think there's some truth in the "ride height backwards" theory (also discussed here).

After struggling with an understeering MR (on Sports Soft if it matters), I gave up and started throwing random settings at it. I very rarely run uneven ride height, but tried out pushing the weight forwards with -20 / +10 anyway. No improvement. So I did the opposite: +20 / -10. Much better! I'll admit, it could be not ride height backwards, but actually better loading of the outside front, but to me it felt like more static weight at the front was giving better front grip. Especially because even exit front grip was improved, which I don't think would happen much if the cause was more weight transfer across the front axle and the static weight was actually being moved further from the front tyres.

 

[budious]

Well I have also seen FF cars get a boost from setting the front spring rate to max and rear spring rate to minimum and leaving the ride height at 0 on both ends; I think the fault lays outside of the ride height.

 

[Motor City Hami]

Well I have also seen FF cars get a boost from setting the front spring rate to max and rear spring rate to minimum and leaving the ride height at 0 on both ends; I think the fault lays outside of the ride height.

I kinda agree. Just my opinion, but I think that all of these supposed suspension glitches are a result of not setting up the LSD properly. Anytime you have to max out settings in opposite directions, something else seems to be to blame. I have tried the ride height, spring and damper glitches that have been mentioned and each can improve oversteer or understeer, but all created other funky feels to the car. For example, with the really high front, low rear setting, clip one curb or one bump/downhill section like Nurburg or Trail Mt and get snap oversteer.

I am experiencing the same fast lap times by spending time fine tuning LSD, then toe, then ride height, then camber, without the funky glitch tunes. The cars seem to be just as fast, but much more predictable and consistent. I haven't done any of the time trials yet because I'd rather race than push for a single fast lap. Probably why I like a car that would be consistent over 20 laps rather than just hang on for one quick one?

 

[Osr20_L]

Ok I have this issue that I wanted to bring up due to difficulty having tuning some cars. This may not be a bug but I have a theory I need help solving. Right now if you look at some of the time trails replays you can see some people running there car with their ride height reverse with there front set height and rear set low on fwd cars. I know for a fact this is the worst possible thing you can do to a fwd car. So I tested it out.

I took a FTO out for a spin and tuned it for around hp did a stage Weight reduction. I tuned it like a regulr car and i got a lot of understeer with it. Tht was expected but i went and reversed my ride height settings and magicaly the car felt so much better and drove faster. I dont want to hear from people you dont know how to tune etc. I know how but after testing this out it make me wonder why are people compensating their oversteer so heavly with their dampers and swaybars. It starting to make sense if you look at your ride height settings. If you do believe me just take your favorite car and reverse the ride height youll see a difference.

i don't think the bug lies on the suspension cause while tuning a FF car for drag racing, if you lower the front, you will have better grip going forward like in real life, but if you lower the rear, you will have less grip.. try it you'r self on the test track and the 400m..
Thats just the case of drag racing, but the problem is evident taking turns, so, maby it's not on the suspension.. i tink is more an issue of weight transfer