Is Suspension Tuning Backwards? - A Test with RX-8

[Nelsy]

ok just started with my little MX-5 the other day...
my spring rates are lower at the back and higher at the front...
the car seems great, i've nearly tuned out the understeer whilst breaking...
but it has alot of understeer whilst on the throttle..
so i rekon i'm gonna get the racing sus kit and work on that a bit..


so far in my opinion, with the lower BHP cars i'm tuning, the suspension is working how i thought it would be... how it always has been...

ie; so far every car i've tuned all less than 300bhp, have acted how they should when it comes to tuning the suspension... the only real problem i had was when i took the '64 G4 and hardened up the springs.. the car wouldn't stay on the road.. but i guessed older car didn't handle as well as newer cars.. so i softened the springs made the ride higher.. and now it is controllable..

please bear in mind that tuning a car, for me, takes a real long time. i could spend just under a week on it, and still not have it perfect.. sometimes i even leave parts out. depends how it feels.

the one real difference i've noticed in GT4 is that you can't recklessly fly through a turn like in GT3, all the sequences for turning well seem to be far more delicate and intricate.. 'one could say there's a certain finesse involved'

hehe forgive me i'm just rambling on...

 

[sukerkin]

I still haven't had chance to do any extensive work on this yet (too busy doing Licenses and Cash Cow races ).

However, a couple of questions to help eliminate suspects for the weird behaviour that has been noted with Spring Rates.

1) I'm assuming that people have been running with ASM and TCS off?
2) Likewise, have testers been using new cars (or if second hand have they Refreshed the Chassis Rigidity)?

The second point is an intriguing one as I found my second hand TVR's had lift-off understeer and generally were somewhat 'imprecise' until I did chassis refresh {henceforth abbreviated to CR } and, lo, the ability to throttle steer a TVR returned as if by magic . It would seem that if the structural integrity of the vehicle is compromised then you do indeed get all kinds of odd, counter-intuitive, responses.

 

[///M-Spec]

I don't need a detailed rundown of testing to know that when I start at springs f8/r12 shocks 6/8, the car understeers in all situations (entry, midturn, exit, WOT), and then OVERSTEERS GREATLY in all situations (entry, midturn, exit, WOT). On all tracks, in all weather conditions, with any car I choose.

Yes you do. If you did a more detailed analysis, you would have realized that the test you did at Trial Mountain with the N1s could have any results depending on how the car was driven. I could easily make the car UNDER or OVER steer with any of the setups you posted in almost any corner at any time, depending on how aggressive I was with the throttle and what my speed at turn in was. In short, I easily replicated contradictions to your results within a few laps. So sorry, I’m not buying this.

I don't know how you came to the results you did, other than you can't look beyond your own guide. Even Greyout can't replicate your results.

Oh yeah. Anyone who disagrees with you must have a personal defect that prevents them from seeing objectively. Real eloquent. I’m convinced already.

Ask yourself this: What is more plausible? That the physics work, as they do, on all tire types, or that there are THREE tires types that have the opposite physics from the REST of the game.

I said I was “wondering” that, not “I know for sure and I’d bet my life on it.”

Here's the quote:

I am wondering if PD simply gave you a different physics model DEPENDING ON TIRE SELECTION.

Look around this site and you will find plenty of people who believe the Arcade Mode physics are different from GT Mode. Most OLR rules dictate WHICH mode to use depending on the event, so there is no question everyone is running the same thing. It’s not that far fetched.

Stop exaggerating my position just to make a straw man for yourself to knock over. It’s very obvious and getting pretty old.

Er...you were saying? You're the only one who isn't seeing what the rest of the board is seeing, what our own eyes see. And it's for only THREE tires types, as well. How odd is that? So...yeah....I would say its DEFINATELY WARRANTED.

I see. So now you and Greyout constitute the entire board?

M-Spec's gone bye-bye, what do you have Greyout?

Dude. You need to chill with the cheap shots. You keep making this personal and we’re going to have a problem. 👎

I'm using Dual Shock for all tests (unless you think they used a third physics engine for Dual Shocks).

When did I say that? I didn’t.

Input device matters because the device itself impacts the way people drive in the game. It is variable, just like Begineer/Professional/Simulation steering settings in the options menu.

I have no idea what your skill level is with the DS2. You could be like famine, who can gold all the tests and finish all the Mission Hall events with a DS2, OR you could be average Joe with DS2 who struggles just for a Silver or you could be somewhere in between. The better a driver you are, the more likely you will notice subtle variations in car balance and the more consistant a driving test you are likely to conduct. You are obviously not famine and since I don't know you, all of this is a question mark for me.

Should eliminate TWO of those requirements right off the bat. As for the third, I did that in my first post, and most recently ("all circumstances" physics are reversed). However, because I never changed my three tuning SETS for the RX-8, I went back and bought N1s to do the SAME test as the original post. Here it goes:

TEST

Car: RX-8 Type S(J) - FR 285HP (I assume this car shares the same physics engine as the rest of the game)
Tires: N1 (According to M-Spec, does not share the same physics engine as rest of the game)
Track: Trial Mountain (I assume this shares the same physics engine as the rest of the game)

SETUP 1 --- SETUP2 --- SETUP3

Springs f10/r10 --- f10/r15 --- f10/r6
Height 120/120 --- 120/120 --- 120/120
Bound f8/r8 --- f6/r8 --- f8/r6
Rebound f8/r8 --- f6/r8 --- f8/r6
Camber 2.0/1.0 --- 2.0/1.0 --- 2.0/1.0
Toe 0/0 --- 0/0 --- 0/0
Stability 4/4 --- 4/5 --- 5/4

RESULTS:

SETUP1 (Default): neutral, some real minor throttle oversteer
SETUP2 (rear stiffer): Very noticeable Understeer, in all turns.
SETUP3 (rear softer): Moderate to serious oversteer, in all turns. Braking, mid-turn, exit.

As I stated in the first portion of my post, I refute your claims that the RX-8 can be set up to ALWAYS understeer or ALWAYS oversteer. I replicated your exact setup and I could make the 8 understeer or oversteer anytime I wanted to on almost any corner at Trial Mountain simply by changing the way I drove it.

Look. If you want to keep working on this, great. If I find I'm wrong about anything, I'll be the first person to say so. If I was worried about the guide, I wouldn't even had this conversation in the first place, let alone agree with you and Greyout on the Sport tire model. I think I've been more than fair towards you in particular. So do everyone a favor lay off the attitude. If this thread turns into another argument, I will have no problems locking it.


M

 

[Duke]

Could people PLEASE put aside preconceived notions on how the game SHOULD work, and just test how it DOES work? Get a family member or friend to adjust the game's slider for you, blind, and then do a blind test.

However, you do appear to be somewhat inflammatory and aggressive towards M-Spec who has, to me, at least attempted to thoroughly provide a detailed explanation of his findings and he has not - anywhere - been aggressive or derogatory of you or anyone else, even if their findings seem to be contrary to his.

I would like to see more findings added to the pile and I - for one - will be attempting to correlate engine position and drive type to suspension settings. I would hope ... and I do not know what these will be yet ... that if my findings differ from yours, even in part, that you will not see this as a reason to dismiss me as some form of lying M-Spec-wannabe and fangirl.

Personally, I am grateful that you brought this subject forward as I think it has sparked one of the more interesting discussions anywhere in the forums, but - please - realize that it's not a personal attack upon you if someone concludes findings slightly different from your own. Heck, I could sit in front of GT4 tonight and find that what you're saying is exactly what I find, but then I will not take that as some form of M-Spec ploy to deceive the community and take over the world, but rather simply one more piece in an ever revealing study ... a study I will still be following with open-minded interest even AFTER I've done my own testing.

Hear, hear. Well said, Kolyana.

Maturin, I've been reading this thread since it began. Since I have not had time to do extensive GT4 testing of my own, I've stayed out of the technical side of it. Once I have time to get my hands greasy I will report my own findings.

You seem to have a bit of attitude here, and I'm not sure what's prompting it, so knock it off, OK? People are posting their findings as they experiment. No one is ridiculing you. No one is disagreeing with you just for the sake of argument. What they're doing is thinking for themselves. If you've got a problem with that, the way to show it is not to get up in their faces and imply they are idiots or liars.

Keep your disagreements on a less personal level. A number of the posters here know quite a bit about the scientific method and how to apply it carefully to competition car tuning. You may have convinced yourself, but you have not so far succeeded in convincing everyone else. We're trying to listen to you and weigh what you're saying - but your attitude is not making that very easy.

Any questions?

 

[samagon]

to throw another log on the fire...

I've made some casual observations (no serious testing, just anecdotal) that when the springs are set light, and the shocks are set too hard that my cars understeer going into any turn, and I have to brake way early, and way too much for any turn.

again, this is just my casual observations and if someone that isn't as lazy as I am wants to test it, they can.

I think though, that a good test may be to set the car up to be decently neutral, then set the springs overhard, or set the shocks to be soft. and then reverse that and see what the results are.

 

[Maturin]

1) I'm assuming that people have been running with ASM and TCS off?
2) Likewise, have testers been using new cars (or if second hand have they Refreshed the Chassis Rigidity)?

Yes to both (bought the RX-8 new).

It's not close, it's not "subtle", the effect is reversed. You're GTPLANET's only hope Sukerkin, the others have their head in the sand, and I am out of here.

 

[Greyout]

another data point:

new car - Audi S4.

it has about 500hp, stage 2 weight reduction, roll cage, and soft sport tires.

it took spring settings as mentione above, to dial out the understeer (very stiff front, soft rear).

the damper settings are opposite of the spring settings. Stiff front dampers and soft rear dampers caused understeer when I turned in. Soft front dampers and stiff rear dampers reduced the understeer incountered on turn in.

"soft" is like 3 bound/6 rebound, and "stiff" is like 7 bound and 9 rebound.

One thing I do not like about the soft rear springs is the extra squat on acceleration out of slower corners. PD's physics engine seems to act like the flatter a car is in a turn, the less weight transfer is happening (hence the stiff front = better front grip theory). I hope this is not translated to squat & dive also. The more a car squats in GT, does that mean it has less grip on the front tires?

My cars seem to support that idea, as my RWD cars that are setup to handle well in steady-state cornering (stiff front / soft rear) have significant understeer when on the throttle and coming out of a corner.

 

[Duke]

You're GTPLANET's only hope Sukerkin, the others have their head in the sand, and I am out of here.

I'd rather you stay and change your behaviour and contribute, but it's your decision to make. If you'd rather run away than have a mature discussion, we won't miss you.

 

[DopeStar]

Interesting topic....Ive had some trouble setting up my cars to oversteer a bit in the corners but ive managed to get most of them to do it with normal understanding of how suspension works. The game does have a strong tendency to understeer no matter what car your driving and I find the game much more suited to front wheel drive cars then rear drive cars, atleast in the manner of suspension settings. The biggest help ive found for correcting understeer in my Mazda 787B or any rear drive car is to lower the front end bound and add slightly stiffer front springs. This seems to work with my driving style.

Also my AWD cars tend to be easier to drive if I set them up as a FWD car along with moving the VCD(I think thats it, but its the device which control how much power goes to the front wheels or back wheels) to 35 or higher. I usually run higher bound and rebound in the back at no less then 2 clicks apart with rebound being higher, I still get understeer but its hard not to when you head into a corner at 90+mph but I can get the rear to slide out just enough to get aroudn the corners better.

Im gonna test some of this tonight after work, maybe Ill pull my Ruf CTR (Ive been very upset with this car and the money I spent on it) out of the garage again and see if I can get it to handle the way I assumed it would.

Im at work at the moment so no hared numbers but ill do some testing and add my input when I have some hard evidence.

One last thing, I think some of you guys my be over tuning your suspension. I find if I make small adjustments and test longer i get better more honest results instead of makeing drastic changes and doing one hardcore full wick lap and *****ing that the car sucks because I never took the time to get use to the new settings.

Great site by the way, im fairly new (this is my 3rd or 4th post) but im having a good time here.

 

[awdrifter2]

Deleted.

 

[DopeStar]

One question, how soft are we talking here on the rear suspension. Maybe its just so soft that it hits the bumpstops and goes infinite, as stated before I believe, causing the car to slide so much. Or its to soft to keep any kind of weight on the inside rear tire that it slides out. Also the dampeners seems to play a massive roll in suspension tunning in this game so I dont think we can say that just soft rear springs cause oversteer since all the settings work together as a system and if one is wrong the car will not handle correctly but like I said im at work and will test this later.

I read the whole thread but maybe I missed this somewhere.

 

[///M-Spec]

I tried this on many cars now, hard front/soft rear = oversteer. That's just it. I still have some understeer exiting corners, but that might be the full customized LSD or the fact that I use DS2 controller so I have to leave TCS at 1, so I can't overpower the rear wheels out of the corner.*

*emphisis mine

That will skew the results. Try it with the TCS off. Set all driving aids to 0. It should give you the chassis natural balance.

I think Maturin is right about you shouldn't think about how it should work, but just test hold it does work in GT4. I recommand making 2 settings, then let a friend/family member drive it, then ask them which one oversteer more. That way you get a more objective result.

I am testing how things work in GT4. I'm just getting different results and we're trying to figure out why. The TCS can make a BIG, HUGE difference in how a car behaves and I believe it contributes to understeer.

In my real car, which has a load of computer nanny controls, they are all programmed to produce understeer when the car looses traction with a yaw moment. That is because understeer is SAFEST for the average driver. If I turn OFF the computer, I can get big, lurid tailslides anytime I wished... on a car that prodominately understeers. I would expect GT4's ASM/TCS to behave the same way.

I will do a double-blind test as soon as I can. My wife won't touch the PS2, so I have to get a buddy to do it.


M

 

[///M-Spec]

One question, how soft are we talking here on the rear suspension. Maybe its just so soft that it hits the bumpstops and goes infinite, as stated before I believe, causing the car to slide so much. Or its to soft to keep any kind of weight on the inside rear tire that it slides out. Also the dampeners seems to play a massive roll in suspension tunning in this game so I dont think we can say that just soft rear springs cause oversteer since all the settings work together as a system and if one is wrong the car will not handle correctly but like I said im at work and will test this later.

I read the whole thread but maybe I missed this somewhere.

Yep. Greyout has already posed the theory. I don't know of a way to test it practically in GT4, however.

And I agree there is a tendancy to oversimplify results and confuse the issue further. Suspensions are complex things. I would bet GT4's suspension model is more complex than we give it credit for. That is why I have always carefully stated that understeer and oversteer are not absolutes. That a car can do either depending on how you drive it and that tendancies toward understeer and oversteer are just that: tendancies.

Welcome to GTPlanet, btw.


M

 

[DopeStar]

And I agree there is a tendancy to oversimplify results and confuse the issue further. Suspensions are complex things. I would bet GT4's suspension model is more complex than we give it credit for. That is why I have always carefully stated that understeer and oversteer are not absolutes. That a car can do either depending on how you drive it and that tendancies toward understeer and oversteer are just that: tendancies.

I do think that GT4s suspension model is by far more complex then we think it is, I have played with setting on several cars though and the only thing I cant seem to initiate in the car is oversteer while reducing understeer. I fear the problem has more to do with how im driving it though then my settings. Its easy to brake way to deep into a corner, producing understeer. But Ill keep tweaking the settings till I get it to feel right.

Welcome to GTPlanet, btw.

I am happy to be here!!



Also the test bed for this test is a RX-8 bone stock with racing suspension and driving aids off, right? Or are there other mods we are using for this test?

 

[///M-Spec]

I do think that GT4s suspension model is by far more complex then we think it is, I have played with setting on several cars though and the only thing I cant seem to initiate in the car is oversteer while reducing understeer. I fear the problem has more to do with how im driving it though then my settings. Its easy to brake way to deep into a corner, producing understeer. But Ill keep tweaking the settings till I get it to feel right.

Braking deep is the kiss of death in GT4. It's actually very cool since you basically have to learn to threshold brake without any pedal feedback. I've learned to watch the brake force indicator in the dash to make sure I'm using just the right amount to get the job done. 100% with N1s N2s or N3s usually means you can forget about turning the car at the same time.

Also the test bed for this test is a RX-8 bone stock with racing suspension and driving aids off, right? Or are there other mods we are using for this test?

Well the test has gone through several iterations at this point, since everyone who tries it changes something. My test setup is detailed in THIS post, if you care to reproduce it. My car was Bone Stock except for Racing Suspension with a choice of Sport Medium, N2 and N3 tires (free at tuner shop). All driving aids were off. I used a Logitech GT Force in Sim mode.


M

 

[Pontiac Le Mans]

Now I wouldn't say the suspension physics is backwards, but I just softened my 91 Skyline GT-R N1's rear suspension, the car is noticeably more drifty. The car is really ez to drift now. I'm not sure what this means, but I'm going to do this to all my AWD cars.

Old setting:

91 Nissan Skyline GT-R N1
Brake Balance f20/r12
spring rate f6/r15
ride height f100/r100
shocks f5/r10
camber f4.0/r0.0
Toe f1/r3
stabilizers f1/r7
asm oversteer = 0
asm understeer = 0
tcs = 2
down force f10/r5
LSD f5/20/10
LSD r10/40/20
Trans set
Auto set at 10
VCD 10
Weight Balance 10/50

New Setting (the settings in bold are what I changed)

91 Nissan Skyline GT-R N1
Brake Balance f20/r12
spring rate f6/r6
ride height f100/r100
shocks f5/r5
camber f4.0/r0.0
Toe f-1/r3
stabilizers f1/r7
asm oversteer = 0
asm understeer = 0
tcs = 2
down force f10/r5
LSD f5/20/10
LSD r10/40/20
Trans set
Auto set at 10
VCD 10
Weight Balance 10/50

Try it out.

I'm sorry if I repeat things already said, but I didn't have the time to read it all in detail.

Something essential might have been forgotten. Setting up a car is not a question of radical changes, but a question of moderate adjustments. Going from springs 6/15 to 6/6 is in any case a changement which is to radical: you could have tried 9/12 instead of it first.

6r might be too soft: when rear springs are too soft the weight transfert to the outside is too important: loss of grip, thus oversteer.

Your setting contains some other problems:

* brake balance: 20/12: difference too big: try 14/11
* stabilizers: same problem: try 3/5
* suspension: buy a complete suspension which permits you to differentiate bound and rebound (but I suppose you did it meanwhile). My GT3 experience: oversteering powerful 4WD can be controlled by correct bound/rebound settings.
* why do you put 60 extra kilos in it? It will slow your car down
* I had a serious oversteeringproblem with a ZZII in GT3: resolved it by sending more torque to the front tyres. The problem lies perhaps here: in GT3 most 4WD cars were fastest with 10% VCD, which does not seem very realistic, perhaps this just doesn't work in GT4 (let's try it out)
* There is one info I didn't find in the message I quoted: how many HP has your car? Is it a stock version (concerning power or a maxed out?). If it's a maxed out, don't search for a solution: many powerful cars just can't be managed when they are maxed out because the motor is too powerfull for the chassis/suspensions combination.

 

[Greyout]

6r might be too soft: when rear springs are too soft the weight transfert to the outside is too important: loss of grip, thus oversteer.

6kg/mm springs are still pretty stiff springs. Also There is no point at which physics should reverse itself. As the rear gets softer, there will be more weight transfered to the outside front, and OFF the inside front.

 

[Pontiac Le Mans]

6kg/mm springs are still pretty stiff springs. Also There is no point at which physics should reverse itself. As the rear gets softer, there will be more weight transfered to the outside front, and OFF the inside front.

Indeed, and this just is the problem: the grip you win on one side is less than the grip you loose on the other side; in this case, weight transfer is bad; thus: loss of grip. (I refer here to the setup seminar on gtbythenumbers in which sukerkin participated some years ago)

What seems to have been forgotten here, is that setting up a car is a question of moderation: the best setup is somewhere between too soft and too stif.

By saying this, I (politely) disagree with you on the idea that there is no "reversing" point: when your setup is too soft, you loose grip too, because too many weight is transfert to the outside.

P.S. It's over midnight in Europe now, I have to go to sleep; I hope we'll be able to continue the discussion tomorrow.

 

[Greyout]

But getting soft at one does NOT increase the weight transfer at that end. As the spring stiffness difference between front and rear becomes wider and wider, the stiffer end has more load transfer, and the soft end has less.

There are plenty of examples in the real world of cars running INSANELY stiff rears (off the chart as far as the GT slider is concerned) with front springs that are less then 1/2 then that of the rear.

Until the suspension hits a phyiscal limit (body on ground, tire/suspension component on body, bump stop, etc), there isn't a point that is within GT4's adjustablity range that will cause everything to reverse on itself.

Infact, I started out with everything completely even on my test car. even spring rates, even dampers, even camber, even sway bar. I gradually, over the course of 10 attempts or so, increased the front spring rate by like 2.0 or 3.0 at a time. Each time, the oversteer progressively increased.

When I get home, I am going to change the Front/Rear bias of my S4 to more front to see if that increases oversteer. (HA!) My reasoning behind this is that my FWD cars exibit more low-speed-full-throttle oversteer then my RWD cars do.

 

[Kirium]

Does the data logger provides any figures that are useful in ascertaining what the car is doing suspension-wise? The data logger doesn't seem very simple to use, so I haven't played with it at all, just wondering if anyone here is using it to figure out the suspension physics, or if we're going on feel right now.

 

[Greyout]

no, its pretty straight foward, its more off an accelerometer then a data logger.

 

[sukerkin]

(I refer here to the setup seminar on gtbythenumbers in which sukerkin participated some years ago)

No wonder I was reading through your post and thinking "Yep, I agree with all of that" .

I'm still nurturing the hope that the suspension model in GT4 is actually 'accurate' and that it's simply a matter of finding the limits of the parameters that we need for correct responses.

I also have a feeling that driving style is going to have an even more major impact than it did in GT3 - I know that I've had to change a couple of aspects of my driving to allow for the new braking 'model' for example.

Until such time that I've been able to do some experimenting and testing of my own I'm trying to stay away from 'definitive' conclusions. I'm also expecting to find that there are going to be Two Camps on this issue for the life of the game (just as there were Dark Side tuners in GT3). Neither side will have the right of it, they will only have what works for them.

One side note that may really muddy the waters is that, according to the GT4 review I read in one of the Playstation mags over here, the physics engine was modified for the PAL release ... as if this wasn't compicated enough to resolve rationally .

 

[awdrifter2]

Deleted.

 

[awdrifter2]

Deleted.

 

[sukerkin]

Seeing the pattern settings suites are taking it's starting to look fairly obvious why the "Front Stiff/Soft Rear = Oversteer" concept is having an effect.

If you make the, fairly reasonable, assumptions that the physics engine is geared (yeah, automotive pun ) to simulate the effect of greater weight borne by stiffer springs and has a more realistic tyre grip model than previously, then front springs three times the stiffness of the rear means that you have removed much of the weight from the rear wheels.

Now, if tyre adhesion holds out then you would probably get understeer from this but if the grip level is exceeded (due to not enough weight pressing down on the tyres) then you get the reverse of what you'd expect i.e. oversteer.

As noted in my recent post, until I get some spanner time in myself I'm not going to state anything categorically but my gut feeling (backed up by how much more realistically the 'stock' sports cars handle) is that, with balanced spring rates and proper damper adjustment, then 'Real World' tuning principles can still be applied successfully to the GT4 environment.

I can't say this with any authority of course because, in common with most of us, I haven't had any input into the game code . Only track time and 'feel' will tell in the end.

 

[awdrifter2]

Deleted.

 

[Nelsy]

Greetings guys, just a lil update with my MX-5..
well i have all the understeer tuned out whilest breaking..
but i wanted to work on tuning out the understeer while on the Throttle...
so i look at the spring rates first.. since i'm not yet running racing sus..
as i thought they were tuned to slight understeer.. (front being higer than rear)
so i raised the rear a bit, and handling improved..
i thought yes, this is great..
and a few laps later the handling was going good..
so i wondered, 'how much more can i get?'
i then started lowering the front springs. and then handling improved again..
(bare in mind i'm only ajusting the suspension by 0.1 - 0.3 at a time..)
and then at random i lowered the front y a further 0.1.. and to my shock the cars balanced seemed to be destroyed..
oversteer at nearly every point on the track.. i was having to fight the car to keep it on the road...
so i just ajusted the fron t springs back to how it was before...

basically i was shocked at how much difference that tiny movement in springs affected the car..

not sure if any of this helps the current discussion, but in my opinion the GT4 engine works how it should, and i'm having no problems with backward sus tuning.

Nelsy..

 

[awdrifter2]

Deleted.

 

[///M-Spec]

Unfortunately, I don't have a DF steering wheel, so I have to leave TCS at 1 otherwise I would just smoke tires and not go anywhere. My real car is a 92 Talon TSi AWD. There's no AWD version of this car in GT4, and I haven't find a 2000 Accord (dad's car)yet, so I can't compare it to real life. But in GT3, even with TCS on and ASM off, the Accord feels the same as my dad's car in real life. So I don't think the TCS would/should cause dramatic difference in handling. Someone else that has a driving wheel should test the TCS theory out.

Maybe you could remove some of your HP mods for the tests.

DSMs are cool cars. Post a pic in General Automotive when you get a chance. There's a few other members here with them.

I think traction control has a large impact on the balance of a car anytime the throttle comes into play. The reason is because they typically retard ignition timing and/or reduce fuel or in the more sophisticated drive by wire systems, simply reduce the throttle until the computers sense the tire is no longer slipping.

Since oversteer, by definition, means the rear tires are spinning or slipping, a system that keeps traction in check defeats any sort of throttle induced oversteer.

Of course this applies mostly to rear drive cars.

EDIT: Oh, and just to clarify on what I wrote earlier in the thread..

Cuz M-Spec said that N and S tires are reversed

I'm not sure they are reversed, per se. I did get lots of lift-throttle oversteer with a soft rear spring/shock setup, but I didn't get all the understeer with a stiff rear spring/shock setup on the RX-8. With my testing, I did not notice much change except for the roll stiffness.

And also let's keep in mind the ONLY car I've been testing with was the 8. And a little bit with the M3.

The more I think about this, the more I think definitive, hard and fast rules about car balance and suspension tuning do not apply in GT4. That techniques will vary a bit from car to car and perhaps even track to track. A one-tick change in spring rate for one car will probably not do the same thing for another.


M

 

[Greyout]

Since i'm not yet running racing sus....

I meant to bring this up - perhaps its a flaw with the pure-racing suspension, and not the sport or semi-race?

I bought a Toyota Supra last night, and equipped it with the semi-race suspension. It understeered slightly, so I increased the front spring rate, like I had done before.

It did not fix the problem, and it may have made it worse... but I was tired & went to bed.