General suspension balance - have we been fooled?

So far, all the guides I've read suggests softening the front compared to the rear to reduce understeer (and vice versa), like in real life... and this got me into some serious messes with a few cars (Clio V6 for one). However, to me these settings seem 100% reversed. One of Tankspanker's posts in the drifting forum got me to try reversing it up, even though I never noticed it working on the drifting FR's I tuned at the time.

Try getting out a Clio V2 (I used the phase 2 one) or Speedster and set them up stiff in the front and soft in the rear (12/6 to really notice it) and they'll start spinning if you breathe on the wheel. Tighten the rear a bit more than the front (e.g. 9/11), and the Clio will handle like a dream while the Speedster will start to understeer.

I also got very 'telling' results on a few 4WDs (TT, Impreza RC to name 2) setting the springs to 12/6 and dampers/stabilizers to match. The TT went from pushing like hell to actually oversteering on turn-in, and the Impreza almost felt like an MR.

Tuning FR's didn't produce such overwhelming results for me, but what's other people's experiences with this? Just freak occurrences on a few select cars, or have we been fooled?

PS: As usual, I couldn't find any directly relevant topics.. but feel free to redirect me to one or keep this alive to sort out this IMO importan question. Also, I haven't seen convincing results from tuning stabilizers any way, though I THOUGHT soft front/stiff rear helped on turn-in when I tuned my cars' springs more 'conventionally'.

what are the ride heights?

when a car bottoms out - it looses traction, if its too soft in the arse, it will bottom out, so even though it is getting more grip through the softer springs, it then looses that as it bottoms out.

you always have to compensate for soft springs with a raised ride height.

The problem with this is that those are MR cars. You can't really set up MR cars with stiff front springs and soft rear springs, as this produces what is known as roll-oversteer, something also prevalent on certain FR cars like the old Tuscans. It's just more noticeable with these cars because the weight balance is shifted towards the rear because of the engines, so a soft rear end allows all that weight to just slide around.

Springs should be set harder, naturally, where the most weight is... but there are exceptions. Some AWD cars and FF cars are set-up with stiff rear springs to induce lift-off oversteer or neutral steer, to counter the natural tendency of these cars to understeer. But stiff front and softer rear springs still work well for FR cars.

I always keep my ride height sufficient, and these settings were kind of extremes to prove my point (the Clio was more than a handful even with even settings f/r).

The roll-oversteer point is understandable, but the weird thing is how much of a difference this made on the 4WD cars (especially the TT). They don't push nearly as much with soft rears, and most of them are still extremely stable.

Ske

I always keep my ride height sufficient, and these settings were kind of extremes to prove my point .

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without posting more complete settings it was hard to tell. i find most cars ride way too low. i find raising them considerably improves overall driveability.

as an example i run most cars with the rear between 10 and 30 mm above the front, and often at about max ride height in the back.

I usually go for middle height setting for the front, and 10-20mm higher in the rear for smooth tracks (depending on vehicle weight and spring rates, but I tend to have a decent margin). I also usually run amalfi to sort out bouncing/bottoming out (the bump just past the first hairpin gives a nice pointer). Main testing grounds were Fuji, Montegi and Suzuka. The mad oversteer I got from the MRs were no more pronounced in turns with camber/bumps/dips than in flat ones, and the increased turn response from 4WD/FR was also the same for any turn. So yes, my ride heights are well sorted.

All the other settings were stock for this test, and with 12/6 springs I'd usually start out with dampers at 6/8 front, 3/4 rear, though small adjustments here doesn't really make or break anything.

PS: For FRs, I found that the same thing happens when reversing the settings. Semi-stiff front/soft rear seems to make the ones I tested (New RX7, Crossfire, Chevelle) noticeably more neutral in tight turns, although they seemed to become a bit loose on high speed entry at least with the extreme settings I tried first.

Unfortunately, PD seems to have confused things along the way by not including even a basic tuning manual. The problem is that many of the tuning settings don't function like they do in real life. Add to that the problem that all of the tuning guides appear to be written by people who know how to tune suspensions in real life, and who expect GT4 tuning to behave in a similar manner, and things get messed up really fast.

The short of it is that somebody way better at tuning that I am should really write up a guide that *completely ignores real life physics* and just plainly states what does what in GT4.

You're right by the way, except on very rough tracks where bouncing leads to traction loss (the Ring), the stiffer end of the car sticks better in GT4. Thus, stiffening the front springs reduces understeer, creates oversteer, and can lead to the rear-end getting away from you easily if you take it too far.

P.S. I still can't figure out what the heck the toe values mean. I'm relatively sure that positive toe on the rear is toe IN (adds stability), which doesn't make any sense to me.

Whether they're in or out values, I THINK that negative rear toe will make the car looser.. so that's what I going with Can't say that I notice much of a difference in normal cars though what I hear about the toe on the F1 car worries me....

Hmmm... maybe this has something to do with the lack of dynamic camber? Stiff settings in real-life mean the suspension doesn't compress as much, and the camber of the tires in question remain relatively neutral, which can help snap-oversteer on FF cars, while a soft setting means the tires will set at a higher camber angle, which helps compensate for the extra roll. In GT, the reverse is true, as a hard rear has less weight transfer, while a soft rear will not result in higher camber angles in turns but still result in weight transfer... leading to the tires not having optimum grip while being loaded... hence the resulting neutral feel at medium speeds, and weight exacerbated oversteer at high speeds. Soft springs won't be able to stop weight transfer as well, that's why the cars feel loose.

Well, so far so good for the "stiffer the grippier" theory. It seems to work fine for me (at least on N/S tires), though I haven't really tested any FF cars or R tires yet. I know I got the Pug206RC to handle beautifully (neutral, bordering on loose) on R2s with stiffer rear setup, but I'll try it again with teh 12/6 test.

Edit: This definitely works for FFs too, but there seems to be sort of a 'critical' difference or something... for the 206 I found that the rear could be 60-70% as hard as the front. The car didn't get any looser by going to more extremes, at least from my short test right now (216HP, S2, Deep Forest). At least the car got noticeably pushier (more understeering) as I tightened the rear compared to the front.

Editedit: I agree with Panj: Someone with a bit more knowledge and an open mind should leave their reallife principles at the door and try and gather up the 'GT4' physics anomalies in a "pure gt4" tuning guide. Most of the guides I've read so far firmly sticks to RL and will not apply to this game no matter how hard you want it to. A lot of people (including me) have been caught up in tuning "dead ends" because of this. I'd be happy to contribute to a guide, but I'm far from cracking all the "secrets" of GT4 tuning

At least I don't worry about understeer or unwanted oversteer anymore 👍

i personally think of it this way.

springs and anti-sway bars, when stiffer where the engine is, reduce the engine's momentum so it doesn't overload the tires.

i mean, even PD's base settings on japanese tuner cars reflect this with the spring settings.

they have a front 2x as stiff as the back for front engine cars and they practically handle on rails. increasing the anti-sway bar in front improved it even more.

Ske

Well, so far so good for the "stiffer the grippier" theory. It seems to work fine for me

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This is how I've been tuning in GT4 and it always seems to work. The end that you want to stick more - make it harder (including both raising spring rates and increasing stabilizer stiffness)

the end you want to be a little looser - make it softer


also the end you want to stick more - use more camber (within reason)

the end you want looser - use less camber (some of my FF's have nearly zero camber on the back end)

The thing I'm amazed at is people who come up with good settings with wildly differing bound and rebound settings, I am pretty lost as to how that works

Yeah, I'll check whether opposing shock and spring settings work too.. I've seen a number of user settings with that (high F Spring/low F Damper, low R Spring/high R Damper).

I'm finding it weird that people get so different results/feels from settings. In a recent thread about the old Vette race car, I tried the different settings suggested and found mine to give a 5 second per lap advantage at Seca, and 2nd/3rd gear cornering speeds were 10-15 kph faster at average! Granted, I do use the d-pad (in an analogue way )... .but the overall characteristics should stay the same, right?

AlfaAlfa

...The thing I'm amazed at is people who come up with good settings with wildly differing bound and rebound settings, I am pretty lost as to how that works.

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Welcome to the club...

If you have a spare day or so...

https://www.gtplanet.net/forum/showthread.php?t=57763

but still no definitive answers I'm afraid!

v BONES v

If you have a spare day or so...
https://www.gtplanet.net/forum/showthread.php?t=57763
but still no definitive answers I'm afraid!

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Good dig Definitely on topic, but I can't really relate to the 'pro' comments at all.

Started out promising, but after a while started going in a direction I didn't agree with. Everything the 'pros' said for the last 10 or so pages disagree completely with what I've found after basically months of testing

In the name of anything that's good, I can't get a car to get anything but worse understeer if I as much as think about pushing the rear springs past the front springs' stiffness. I've done all those tests, using rougly the same values too, and my results were pretty close to Maturin's original results: higher rear springs = more understeer in just about any case, especially on N tires

I guess suspension tuning for wheels, ds2s and d-pads are way different sciences then.. cause I can't replicate some of those results at all for myself. Only the 'stiffer=grippier' part seems to work out for me.

It's pissing me off, too... am trying to tune a 400hp Focus RS on N-tires, and stiff rear settings only get me understeer. Even the stabilizer settings seem to contradict each other... am going to the gymkhana to work this freaking bug out for myself later...

Want to do a guide on this?

TCS is doing nothing for this car... it can go faster without it, as TCS completely cuts power if you turn the wheel even a smidge...

Although there seem to be a few exceptions, most cars I have tuned seem to work backwards ie. stiffness=grip. But I have also found that spring rates only have quite subtle effects on over- and understeer anyway. This kind of makes sense when you consider how spring rates are used to counter understeer, it is all about keeping grip on the inside front tyre during cornering thus increasing overall cornering grip. By increasing the rear spring rate, the weight transfer causes the chassis to favour the inside front tyre (outside rear spring resists compression). But the spring rate is only part of the story, the stabilizers are likely to have at least as much effect on this process, if not a little more.

I tend to keep spring rates about equal front and back now and use other parts to manage over and under steer (stabilizers, ride height, downforce). But even these settings have some bizarre quirks - downforce (much like spring rate) seems to give added grip at any speed (?) and I have not noticed any additional drag from adding wing yet either!

v BONES v

But I have also found that spring rates only have quite subtle effects on over- and understeer anyway.. But the spring rate is only part of the story, the stabilizers are likely to have at least as much effect on this process, if not a little more.

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Couldn't agree less

I find that spring rate balance has a tremendous impact on the general tendency to under/oversteer, especially on turn-in. As for stabilizers, they never seemed to make much of a difference except on a few cars and for bumps/curbs (I tend to keep them low, at least in the front for that reason)

Rear-stabilizer? Kills rear-end rotation... completely... sends my damn Focus to understeer hell. Front stabilizer seems bizarre also, still trying to form a coherent picture of their effects.

The downforce takes a lot of top-end off, but you won't notice it on many tracks, as it's only very noticeable above 150+++ mph on most cars, and on race cars, you won't notice it until about 180+++ mph.

what seems strangest about all this, is that the question re spring rates and grip is only partially answered here. on a flat track (wehre all 4 wheels are roughly on the same plane) spring rates can be run very high, (warning: drastic over simplification coming!) as this means that the wheel is being pushed harder down - meaning it is in contact with the road more and therefore more grippy. on a bumpy track however, or wherever your 4 wheels aren't in the same plane, higher rates will be a problem. hence higher rates will tend to bounce more due to less travel > less traction. this is modeled in GT4.

i think there should be more detail given when people say that higher spring rates increase grip and don't change balance the way they should (eg higher rear springs > oversteer). the difference won't be that great on a flat track, however on a bumpy track it will make a much larger difference to grip and therefore balance.

Ske

Someone with a bit more knowledge and an open mind should leave their reallife principles at the door and try and gather up the 'GT4' physics anomalies in a "pure gt4" tuning guide. Most of the guides I've read so far firmly sticks to RL and will not apply to this game no matter how hard you want it to. A lot of people (including me) have been caught up in tuning "dead ends" because of this.

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I just want to say that Ske's post is one of the most sensible things I've seen anyone post on GT4 settings. They are not real cars. Real life facts do not apply (much) - do what works.

And if we're having trouble determining whether something works or not - then it must not make much difference...

On a bumpy track, high spring rates cause much suffering, but I've found that low weight causes even more. Even with low rates, a fully lightened car will suffer too much from bumps and weird cambers.

I'm of a mind to leave spring balance alone after all this testing, and sticking to cambers and toes.

Ezz777

...i think there should be more detail given when people say that higher spring rates increase grip and don't change balance the way they should (eg higher rear springs > oversteer)...

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Here's an example of changing spring rates changing the balance the way it should:

The BMW V12 LMR Le Mans car oversteers a bit with stock settings. With these settings the handling is so good it approaches that of the Pescarolos or the Audi:

SR: 11.8 / 9.5
RH: 75 / 78
SB: 5 / 3
SR: 6 / 4
Cam: 2.3 / 0.8
Toe: -1 / 1
Stab: 4 / 3
DF: 63 / 88
LSD: 10 / 27 / 11
ASM: 0/0
TCS: 3

The improvement was very progressive as I slowly softened the rear end settings: The inherent oversteer turned to the current near-neutral behavior.

GT4 chassis tuning involves a lot of trial-and-error testing. It can be a real puzzle. However, I have to say that in general, I've observed the opposite of what peeps have reported in this thread. I've been working mostly on race cars and MR or FR high-performance sports cars, and I've pretty much seen softening an end increasing its grip.

That's the problem... all those sets (which we're also familiar with from GT3) seem to go out the window on road cars with road tires.

Zardoz

Here's an example of changing spring rates changing the balance the way it should:

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This is what i have witnessed as well. i have the feeling that some may take an overly simplified view of tuning when they tackle things like chassis balance.

I don't feel like we have been fooled necessarily - but i think those expecting a simple cause and effect as was more the case in previous GTs and other car games, don't get it here because of many of the other factors that influence a cars balance.

We need to take an holistic approach... and umm... its just like, all about the vibe

Ezz777

i think there should be more detail given when people say that higher spring rates increase grip and don't change balance the way they should (eg higher rear springs > oversteer). the difference won't be that great on a flat track, however on a bumpy track it will make a much larger difference to grip and therefore balance.

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Well, as far as my purpose testing goes.. I favor Deep Forest (bumpy) and Laguna Seca (flat) for tracks I know very well, with a mix of radiuses, links, elevation changes and flat curves. I've also used Suzuka East as a testing grounds. The wide S-curves help determine tendencies, at least to oversteer. These tracks seem to help cover most of the game as far as tuning is concerned, though tracks like Nürburgring and La Sarthe require different tuning.

I'm also dealing with one thing at a time here (spring rates). I leave the other suspension settings stock, lowered equally f/r (stabs and shocks, mainly), and lowered "to match" the springs. I don't try awkward or experimental stuff just yet, at least not until I feel i understand how spring rates work [ in GT4 ]. From previous testing and trying, I feel that the spring rates have a FAR more pronounced effect on the car's 'natural' handling than any other setting. Note: none of the cars I tested had chassis stiffening, but all had full suspension and drivetrain mods incl a 1.5 way LSD. I use N2 and S2 tires for testing, and I used a 30/20 DF ratio for most cars (25/30 for the Clio). All aids are off, naturally.

When I talk about the effect I get from lowering the rear (I try to generalise a little by starting out with about 16 total F+R rate for a 1100 kg vehicle), I mean the OVERALL 'attitude' (I may use the word wrongly here for you tuning pros, but I think you know what I mean anyway) in turns. I did not take into account lap times, only the general feeling and the amount of confidence the car gives me.

Specific examples:
Clio V6 Phase 2 (~310HP?): With neutral settings or softer rear (8/8-9/7), this car would start to go sideways off-throttle on just about any turn-in. It was relatively easy to balance in a drift, but hardly a car you get fast and confident with. Corner exit on throttle was decently stable and neutral. After raising the rear slightly (7/9), this oversteer tendency stopped immediately, leaving the car very neutral throughout (with slight under/oversteer ON DEMAND). Tightening the rear did not seem to cause any negative side-effects on this car.

Peugeot 206 RC (216HP): First settings (9/10) worked wonders on R2 tires, but showed a lot of predictable understeer in all cases on lesser tires. I ended up with about 9/6.5 on this one, and by now the car would be sharper in turn-in and low-throttle mid turn, but it also seemed to straighten up a bit less with power on. Again, this tuning did not cause any unpredictable side-effects.

Mazda RX-7 Spirit (~311HP?): Started with neutral 8/8 settings, as I assumed this car would have pretty even WD. Push understeer on turn-in and mid corner, but fairly neutral power-on exits. As I lowered the rear and stiffened the front step wise, I found that at 12/6 it would take tight turns a lot easier and more neutral throughout. High speed turns were also more neutral mid-corner to exit, but high speed entries became a bit loose. Also, it seemed to become a bit nervous on high speed corrections on straights or slight bends (like the 2nd to last semi-corner on DF where you just have to alter the direction of the car slightly). I felt the tradeoff was good though, because it allowed for a lot faster cornering in the tight sections, as well very easily executed 'emergency drifts' if I had too much speed at the apex and needed to get more angle/scrub a little speed quickly and gracefully.

Audi TT 3.2 (maxed): Started out with default FC settings, and I was in understeer hell on every corner, in every situation. Pushing it to 12/6 (with very loose rear shocks and 7/8 in front this time), it started to turn into tight corners wonderfully. If pushed, I could even get it to step the rear out slightly without losing composure. There was still some power-on understeer, but not nearly as much as before, and the car responded a lot better to power-off during cornering when I would start to go wide. No high-speed instability on the tracks I tested.

I did do one lap test to check whether my 'feel' would give results, and here's what I came up with (Corvette '63 Race Car on Laguna Seca, S2 tires, aids off, all other settings to default, gear ratios totally wrong, and I ran on automatic ). Results are best of 5 laps.

default - 5/4 ~ 1:41.4
suggested - 9/10 ~ 1:40.2
my test - 10/6.5 ~ 1:34.5

For once, the car didn't FEEL that much different (maybe because of the #(&¤ brakes ), at least not from default to the "suggested" settings. The big difference was that "my" settings allowed me to turn-in much faster and trailbrake some while keeping the car turning, thus keeping the average speed of the tighter turns a lot higher as well as hitting the right clipping points with a lot less effort.

Note that most of my problems seem to have been solved by 'fixing' the turn-in handling of the car. This was IMO the biggest obstacle in getting GT4 cars to drive cleanly, and it certainly helps me maintain better lines and higher speeds throughout corners. I also emphasized the performance in tight corners, as I tend to think that's where the spring rates would have the biggest effect. Another reason for the tight corner and turn-in emphasis is that I also tune cars for drifting, so that was the first trouble area I wanted to sort out in my tuning. However, this seemed to generally improve things in every situation (except the RX7's instability at high speeds).

If there are any specific areas you want explained better or differently, just let me know.. as my memory of this discovery is quite clear, obviously

crikey, i asked for detail and i got ^

that's great stuff. plenty to digest. it begs the next question of whether it is true across the board - and furthermore what situations seem to lend themselves to this phenomena?

Nice stuff!

Ske that is excatly the sort of things i have discovered over the past few weeks.

Changing the springs just like that and getting the same results.

Harder Front, Softer Rear = less understeer more oversteer.
Softer Front, Harder Rear = more understeer less oversteer.

This was just the spring rates alone.

Has anybody know of a good explination of what damper bound and rebound do in GT4 (Not real life). It would be great for a dedicated gt4 settings guide not based on gt3 or real life.