Downforce

[KkillgasmM]

Theres one thing i dont get about it, aren't you supposed to have more downforce on the front than the back to give better handling?

does this mean the number that comes up on the settings? or how far the slider is on the bar?

because some cars have something like 55 as the first number on the front, and then something like 60 as the highest on the back, which doesnt really give much of a choice of what to have.

Its pretty hard to explain really, does anyone know what i mean??

 

[Scaff]

Theres one thing i dont get about it, aren't you supposed to have more downforce on the front than the back to give better handling?

does this mean the number that comes up on the settings? or how far the slider is on the bar?

because some cars have something like 55 as the first number on the front, and then something like 60 as the highest on the back, which doesnt really give much of a choice of what to have.

Its pretty hard to explain really, does anyone know what i mean??

This is more of a tunings and settings thread than a general GT4 one, so I will move the thread to the right sub-forum.

In reply to your question, well it depends on the car and the driver, I would recommend downloading the second of my GT4 tuning guides (link in my sig or see the sticky thread at the top of the GT4 tuning and settings forum) as the first topic covered in the second guide is that of Downforce.

Regards

Scaff

 

[cigano]

I never seen that particular situation you mention. Next time mname the car.

Now, 1st, so as to dispel confusion: Downforce numbers - much as some other values in the settings page, like brake force bias or LSD - are related to the real world in their effects. BUT.... as far as you being able to go, "so if I dial in a 73 rear DF, that means 73 Lbs of downforce (or 730lbs, or 7.3*)"?

No, in GT these numbers live in their own lil world. That 55 doesn't mean you're dialing 55% of the car's total grip to the front. The numbers relate only to each other. A 53 DF front will exert the same DF as a 53 dialed in the rear.

So comparing them and playing them off each other is the only way to put an "amount" on these values. That's a BIG reason we need to test, to gain a sense of how strong a setting's effect will be related to the value we set, and more importantly, related to each other.

So, unless PD publishes them correlations to real world numbers, or some1 undertakes the grandest GT research project and finds the correlations, 1 has to simply keep in mind what the settings are for and not get too hung up on what the value would be IRW. That's really that. You don't hate the sky for raining, right?

Mind you, some settings do relate, like springs and tranny. That's about it, right?

Let's talk about handling. Paste this to your PS2: oversteer is when the front is gripping and the rear ain't. Understeer is when the front is slippin, the rear still pushin. This is LAW. it's what you have to work with.

In very simple - to the absurd - terms, if you think about handling in terms of just "The car follows the front wheels, so where they go it goes.", you may come up with the conclusion you stated at the start. Well, that would be useful info in a world where cars only understeer, and do it often.

You starting to see? If a car is exhibiting the behavior called - so colorfully by our fume-snorting, cud- oops, I mean tobacco-chewing forefathers - understeer, and it has the good joss to be able to avail itself of the wind's gentle persuasions, then yes indeed, more downforce in front than in rear,

You see how I keep coming back to the relation between the 2 being the gist, the main thing?

would make the front tires grip harder. Enuff front downforce would equalize the grip front-rear, and that would bring balanced handling, which is what we really want.

If the car is oversteering, that means the rear tires either don't have as much grip as the front from go, or that if they start out the same, the rears lose grip sooner than the front when at the limit. In that case the rear end is gonna want to whip around, using the front tires as fulcrum. In this case, rear DF higher than front would be the prescription. Again, we're talking simple, coz we're talking only about DF.

You know what I'm gonna say, right? We should really be talking about all settings together, coz that's how they work. They all affect each other. Next time, make your questions about behavior, and let's talk about a whole set-up.

 

[sucahyo]

No, in GT these numbers live in their own lil world. That 55 doesn't mean you're dialing 55% of the car's total grip to the front. The numbers relate only to each other. A 53 DF front will exert the same DF as a 53 dialed in the rear.

Can you explain this more, I am a bit confuse.

BTW, maybe coincidence, but Viper racing use the same downforce numbering like GT.

You see how I keep coming back to the relation between the 2 being the gist, the main thing?

would make the front tires grip harder. Enuff front downforce would equalize the grip front-rear, and that would bring balanced handling, which is what we really want.

Not agree, I find that on many car downforce alone can not be use to balance handling. Try to reduce oversteer in Alpine A310 by only downforce.

If the car is oversteering, that means the rear tires either don't have as much grip as the front from go, or that if they start out the same, the rears lose grip sooner than the front when at the limit. In that case the rear end is gonna want to whip around, using the front tires as fulcrum. In this case, rear DF higher than front would be the prescription. Again, we're talking simple, coz we're talking only about DF.

I have different experience. For me increasing front downforce do not feel as reduce rear grip, it feels more like more front grip. It allow more speed before the front start slipping. It doesn't feel like the rear start slipping at lower speed.

(warning: only by experience):
I can't explain it how, but I feel downforce have different kind of increased traction than other suspension. It's feel different making the car oversteer by using downforce vs spring rate vs stabilizer. It feels the rear tire still loose grip even when I use maximum rear downforce. Increased dowforce feels like reducing the chance of tire slipping caused by rough handling. When the tire in slip condition, downforce only help a little, maybe spring rate do. Maybe downforce setting work better in non tire slip condition, maybe like stabilizer.

You know what I'm gonna say, right? We should really be talking about all settings together, coz that's how they work. They all affect each other. Next time, make your questions about behavior, and let's talk about a whole set-up.

If we know what each setting precisely do, we can make the whole package better. For me it's still a long way to go.

 

[HYBRIDLVR]

Soft, Hard and Medium tire combo's along with Downforce does make a big bifference, Suspension setting and Diff settings will dial the car in to almost perfect.

 

[Scaff]

Not agree, I find that on many car downforce alone can not be use to balance handling. Try to reduce oversteer in Alpine A310 by only downforce.

I have different experience. For me increasing front downforce do not feel as reduce rear grip, it feels more like more front grip. It allow more speed before the front start slipping. It doesn't feel like the rear start slipping at lower speed.

(warning: only by experience):
I can't explain it how, but I feel downforce have different kind of increased traction than other suspension. It's feel different making the car oversteer by using downforce vs spring rate vs stabilizer. It feels the rear tire still loose grip even when I use maximum rear downforce. Increased dowforce feels like reducing the chance of tire slipping caused by rough handling. When the tire in slip condition, downforce only help a little, maybe spring rate do. Maybe downforce setting work better in non tire slip condition, maybe like stabilizer.

If we know what each setting precisely do, we can make the whole package better. For me it's still a long way to go.

sucahyo, what you appear to have missed entirely here is that downforce is speed dependent, the faster you go the more of an effect it has.

You can pretty much discount much benefit from downforce below 60 - 70 mph, but as speeds increase downforce increases, and to the square of the speed increase.

This is covered in the downforce section in my second tuning guide.

Downforce


Downforce is actually the effect achieved by the use of wings on a car, these wings are in theory exactly the same as the wings fitted to aircraft. They are however placed ‘upside down’ when compared to aircraft wings, so the effect is to produce downforce rather than lift (or up-force if you like).

The benefit of this downforce is that it provides additional grip by loading the tyres with aerodynamic downforce; however the wings themselves are light. In effect you don’t add much to the overall weight of the car, but you do gain a downward load on the tyre which creates additional grip.

The downside to this is that the wings also produce drag, which makes the car harder to ‘push’ through the air, resulting in a reduction in top speed.

The interesting thing about aerodynamic downforce and drag is that it increases as the square of the speed divided by a constant. So if your car produces 50lbs of downforce at 40mph, it will not produce 100lbs at 80mph, but 200lbs. At 120mph the downforce would be 450lbs.

However you have to also remember that drag increases by a similar factor, so the more downforce you are creating the more drag you are also creating and the larger the impact will be on the cars top speed.

Changing the angle of attack of the wing varies the amount of downforce. The lower the angle of the wing, the lower the angle of attack and the less downforce and drag are created; as the angle increases the greater the angle of attack and the more downforce and drag are created.

Note: The increases and reductions here are all relative to the previous downforce setting. In addition the more ‘wing’ you use and the more downforce generated the firm the suspension on a car must be set, this is to avoid the chance of the additional load causing the car to bottom out.


As was discussed above, the effects of downforce and drag increase with speed and are only effective at higher speeds (approx. 60mph/100kmh +), with the effects increase as speed does).

At these higher speeds the front to rear downforce balance becomes the dominant force in determining the cars balance. This means that a cars low speed handling balance can be set in one way at lower speeds through conventional suspension settings and another balance can be set for higher speeds through the use of downforce (this is know as the aero balance). You could therefore have a car with a balance towards oversteer at lower speeds and an understeer balance at higher speeds.

Caution does need to be exercised here as speed increases or decreases you move from one balance to the other, should this occur as you are cornering the effect of a sudden switch in the cars balance may well result in a loss of control. As with all tuning this needs to be balanced for the car and track

Any questions please just ask (or download the tuning guides and give them a read), but that should cover the basics as far as downforce goes.

Regards

Scaff

 

[sucahyo]

Yes, thanks for reminding.

 

[cigano]

Sucahyo. That means what, in your 1st language? Ego? I seen a coupla other threads where you're involved in some, ah... pretty heated debating. You exhibit a penchant for spawning wacked ideas, then deciding that's what the previous poster meant.

I stress throughout my answer that tuning is a "synergistic" (whole system effect greater than individual parts performance leads to predict) endeavor, BUT we're taking a narrow - considering DF only - view so we can simplify concepts for the new guy, yet you ignore that so YOU can make the point that the "organic" (whole system view) is best.

Then at the end of your post, you showed your true colors by in fact contradicting yourself with that last remark.

I have an explanation for them funny lil numbers on that lil Viper game, but you're annoying.

This is the capper; I laffed out loud: "I have different experience. For me increasing front downforce do not feel as reduce rear grip, it feels more like more front grip. It allow more speed before the front start slipping. It doesn't feel like the rear start slipping at lower speed."

Youknoe, I read my whole post again. Couldn't find any instance of me saying anything like: "increasing 1 will make the other feel like less". You prolly still don't see what I mean....

Gasm? You copy? Come back. You make any progress with your DF tests?

Oh, and, Scaff; it's enuff that you got a bunch of stuff pinned at the front. Tootin ya own horn is annoying. Speak directly to the kid's particular issue, howbout it?

 

[Scaff]

Sucahyo. That means what, in your 1st language? Ego? I seen a coupla other threads where you're involved in some, ah... pretty heated debating. You exhibit a penchant for spawning wacked ideas, then deciding that's what the previous poster meant.

I stress throughout my answer that tuning is a "synergistic" (whole system effect greater than individual parts performance leads to predict) endeavor, BUT we're taking a narrow - considering DF only - view so we can simplify concepts for the new guy, yet you ignore that so YOU can make the point that the "organic" (whole system view) is best.

Then at the end of your post, you showed your true colors by in fact contradicting yourself with that last remark.

I have an explanation for them funny lil numbers on that lil Viper game, but you're annoying.

This is the capper; I laffed out loud: "I have different experience. For me increasing front downforce do not feel as reduce rear grip, it feels more like more front grip. It allow more speed before the front start slipping. It doesn't feel like the rear start slipping at lower speed."

Youknoe, I read my whole post again. Couldn't find any instance of me saying anything like: "increasing 1 will make the other feel like less". You prolly still don't see what I mean....

Gasm? You copy? Come back. You make any progress with your DF tests?

Oh, and, Scaff; it's enuff that you got a bunch of stuff pinned at the front. Tootin ya own horn is annoying. Speak directly to the kid's particular issue, howbout it?

So rather that raise these issues with Suchayo in a constructive and reasoned manner you feel that insults and borderline abuse is the right approach? Well quite simply it is not, I strongly suggest that you reconsider your posting style.


You are correct that English is suchayo's second language, the thing is he actually makes an effort with it, your own spelling and grammar however are far from perfect.

You will find that the AUP does quite clearly cover both points quite clearly.

You will not behave in an abusive and/or hateful manner, and will not harrass, threaten, nor attack anyone or any group. There will be no racially, sexually or physically abusive or inciteful language tolerated. Any abusive comments made by members will be removed by the Moderating staff and the user issued with a warning or banned, as deemed appropriate by the Moderating staff. No personal attacks on other members will be tolerated. If you question someone, it must be done in a reasonable and semi-friendly manner. Violating this rule will be grounds for suspension and/or permanent removal from the board.

No slang words that promote laziness, ie; "r", "u", "plz", etc. will be tolerated. Decent grammar is expected, including proper usage of capital letters. Repeated violations will be grounds for suspension and/or permanent removal from the forums.

As far as speaking directly to the 'kid's' question and not 'Tootin ya own horn' (sic), the resource is there for a reason, I posted it quite simply because its useful information on the subject the question was asked on, what's more its written in plain English so would seem to be an ideal starting point. If you don't feel it is then I await your own guides with eager interest. I also quite clearly said that if it did not feel it helped or answered his question that he should feel free to ask.


I have taken a look at your profile and it would appear that your account has been dormant since 2002 and GT Planet has grown and changed since then, and I would respectfully point out that insulting members is not a great re-introduction.

Regards

Scaff

 

[sucahyo]

I stress throughout my answer that tuning is a "synergistic" (whole system effect greater than individual parts performance leads to predict) endeavor, BUT we're taking a narrow - considering DF only - view so we can simplify concepts for the new guy, yet you ignore that so YOU can make the point that the "organic" (whole system view) is best.

I see. I say it more like tuning downforce do not help much. I usually ignore downforce tuning when I don't have time. Either max it or don't equip wing.

This is the capper; I laffed out loud: "I have different experience. For me increasing front downforce do not feel as reduce rear grip, it feels more like more front grip. It allow more speed before the front start slipping. It doesn't feel like the rear start slipping at lower speed."

Youknoe, I read my whole post again. Couldn't find any instance of me saying anything like: "increasing 1 will make the other feel like less". You prolly still don't see what I mean....

Maybe I understand it wrongly. It relate to this too:
"No, in GT these numbers live in their own lil world. That 55 doesn't mean you're dialing 55% of the car's total grip to the front. The numbers relate only to each other. A 53 DF front will exert the same DF as a 53 dialed in the rear.

So comparing them and playing them off each other is the only way to put an "amount" on these values. That's a BIG reason we need to test, to gain a sense of how strong a setting's effect will be related to the value we set, and more importantly, related to each other."

I bold the part that confuse me.

In GT2 car stock downforce is displayed, for example,

Silvia Spec R has downforce value of:
0.12/0.21

after R body modification, we can change downforce value:
0.12 to 0.47/0.21 to 0.76

the tuning range of downforce is 0.35/0.55


Silvia Spec R Aero has downforce value of:
0.12/0.25

after R body modification, we can change downforce value:
0.12 to 0.47/0.25 to 0.76

the tuning range of downforce is 0.35/0.51


In GT4 stock downforce is not displayed. Downforce tuning range is about the same as GT2 one. So I am thinking that the value of dowforce in GT4 is a decimal value that will be added to stock downforce value.

So if (just a guess, I don't know where they hid it) a GT4 Silvia has hidden downforce value of 0.12/0.25 then when we use downforce value of 30/30 the resulting downforce value would be 0.42/0.55.


When I say "BTW, maybe coincidence, but Viper racing use the same downforce numbering like GT.", I mean GT here as GT2 and highly suspect GT4 too. I don't realize that maybe you have different opinion about the similarity between GT2 downforce and GT4 downforce.

 

[Scaff]

In GT4 stock downforce is not displayed. Downforce tuning range is about the same as GT2 one. So I am thinking that the value of dowforce in GT4 is a decimal value that will be added to stock downforce value.

So if (just a guess, I don't know where they hid it) a GT4 Silvia has hidden downforce value of 0.12/0.25 then when we use downforce value of 30/30 the resulting downforce value would be 0.42/0.55.


When I say "BTW, maybe coincidence, but Viper racing use the same downforce numbering like GT.", I mean GT here as GT2 and highly suspect GT4 too. I don't realize that maybe you have different opinion about the similarity between GT2 downforce and GT4 downforce.

I have to say I would be interested to see if you could extract the 'default' downforce values for GT4, as most 'road' cars would not exhibit downforce, rather they tend to suffer from to opposite problem, that of lift.

Drive the vast, vast majority of road cars (in the real world) over 80mph and you can feel the steering lighten and lift starts to build, over 100mph and it can start to get a bit worrying.

Regards

Scaff

 

[sucahyo]

I have to say I would be interested to see if you could extract the 'default' downforce values for GT4, as most 'road' cars would not exhibit downforce, rather they tend to suffer from to opposite problem, that of lift.

I think they can use it to indicate how much different car lift too. So that stock Civic do not lift the same way as stock RUF.

Just like Silvia Spec R vs Silvia Spec R aero in GT2 case. I think different car in GT4 have different lift. I think the downforce value is positive because it is the designer choice, not necessarily indicating positive downforce.

 

[cigano]

Hey scuff, if you're the mod, or run this hootenanny, feel free to do whatever strokes your ego. Like you need the prompting... Ha! You seem to have (been allowed to?) set up ya own lil altar to yourself here. I can see the draw, but it feels kinda creepy. Again, if you're the owner, hey, it's your show. As long as you ain't president of SONY and can actively bar me from playing, feel free to float ya boat.

But howbout: If you're the owner, you should be the 1 person most welcoming of different views and challenges. Knowledge not challenged becomes dogma; just "the way it is, though no1 remembers why anymore".And anyway, if you are the owner and you set this site up just to lord it over every1, I just as well rather keep away.

I don't spend my GT time writing "guides", I play, and if I talk about the game, I go to the point that's being dealt with, not quote some abstract technical info, which prolly a lot of the readers "know" but don't really understand, coz in their mind it's not realted to Real World effects.

Guides would seem a good way to combat this ignorance. Well, it ain't. They don't come alive in players' minds, so they don't learn to apply the 411.

I've found that talking concisely about a setting (what it's for) then immediately applying it to an issue pays off better in useful understanding for the player.

But you gohed n write ya lil head off. Seems to do you good, huh?

Now you, Suc, when I say 53 in front feels like 53 in rear... My bad. I mean, "If you dial in 53 DF in front, And Also dial it in in the rear, they will both be subject to the same forces." Can you dig it? I most definitely did NOT mean, "If you set it in front the rear will feel it too!" Got it?

We just met. I don't know what your agenda is here. Mine is the discussion and disemination of GOOD, PROVEN, USEFUL, 411 about the GT car sim game series. Since I can't see you I didn't know if you're just picking fights over semantics or if my words were not clear enuff. What set me off is: there is nothing I hate more than being misinterpreted. Well, if some1 said I gave out bad info, that I'f hate more.

About the "related" part, do ya own tests: take a full-mod car, leave all settings stock, except for 1, your choice. Test lap. Then reset that setting to stock, and change another setting. Test lap.

While you're doing this you will - of course - be taking notes on how the setting affects car behavior. Then come in and change both settings. I will bet ya money the effect on behavior of both settings together is different from the behavior exhibited during their single setting laps, not what you'll expect. They will not be adding their effects but multiplying them. You dig?

Got a Q for ya (Scuff, you can play if you want): what KIND of spring-damper set-up is most useful for maximizing the effects of downforce? See, DF's effects on suspension are more readily apparent, but let's look at it the other way. Not a trick Q; I do enjoy these exchanges of info and insight.

 

[Scaff]

Hey scuff, if you're the mod, or run this hootenanny, feel free to do whatever strokes your ego. Like you need the prompting... Ha! You seem to have (been allowed to?) set up ya own lil altar to yourself here. I can see the draw, but it feels kinda creepy. Again, if you're the owner, hey, it's your show. As long as you ain't president of SONY and can actively bar me from playing, feel free to float ya boat.

The name (or rather user name) is Scaff and it would be appreciated if you could use it correctly.

I am a Moderator here, but not the owner of the site.

As far as setting myself up as a anything here, well that does rather seem to be in your imagination, certainly in the time I have been here its the first time that rather strange accusation has been laid at my door.

However what you have already been asked to do is use proper English and grammar in your posts, something I can see you have chosen to ignore. Please change that ASAP, as has already been pointed out it is a condition of membership. That puts the choice firmly in your court, either you chose to follow the AUP or you chose not to be a member.

But howbout: If you're the owner, you should be the 1 person most welcoming of different views and challenges. Knowledge not challenged becomes dogma; just "the way it is, though no1 remembers why anymore".And anyway, if you are the owner and you set this site up just to lord it over every1, I just as well rather keep away.

I don't recall disputing any form of new views or approaches, quite the opposite I have actively been involved in many, many discussions of this nature, but then I'm quite sure you have taken the time to read all of the threads relating to those discussions before making this decision about me.

I don't spend my GT time writing "guides", I play, and if I talk about the game, I go to the point that's being dealt with, not quote some abstract technical info, which prolly a lot of the readers "know" but don't really understand, coz in their mind it's not realted to Real World effects.

Guides would seem a good way to combat this ignorance. Well, it ain't. They don't come alive in players' minds, so they don't learn to apply the 411.

I've found that talking concisely about a setting (what it's for) then immediately applying it to an issue pays off better in useful understanding for the player.

Have you actually read either of my guides?

I strongly suspect not, as if you had you would know that rather than being based on any form of abstract technical info (although automotive training is my background), they are based on my own, very, very extensive testing on GT4.

Guides may not work for you, but I can quite safely say that they have worked for a lot of people. I also think its rather bold to claim that they don't help it come alive in player's minds. Are you in every players mind? The guides strongly advocate testing an experimentation to find set-ups that work for the individual driver, and one hell of a lot of people find the basic concept of how and where to start quite intimidating, just because you don't find you need them does not mean that's the same for everyone.

But you gohed n write ya lil head off. Seems to do you good, huh?

And that comment was needed for what reason exactly?

We just met. I don't know what your agenda is here. Mine is the discussion and disemination of GOOD, PROVEN, USEFUL, 411 about the GT car sim game series. Since I can't see you I didn't know if you're just picking fights over semantics or if my words were not clear enuff. What set me off is: there is nothing I hate more than being misinterpreted. Well, if some1 said I gave out bad info, that I'f hate more.

I'm not picking a fight with anyone here, rather you have waded into a forum and displayed an attitude that is not what we are looking to attract here at GT Planet.

As far as your words being unclear, well quite frankly yes they are unclear, you appear to have little respect for the English language and you have been asked to resolve this.

The information I provided was also good, proven and useful, yet you have dismissed it out of hand, something you may notice I did not do in regard to your comments, yet you accuse me of not being open to other viewpoints and approaches.

About the "related" part, do ya own tests: take a full-mod car, leave all settings stock, except for 1, your choice. Test lap. Then reset that setting to stock, and change another setting. Test lap.

While you're doing this you will - of course - be taking notes on how the setting affects car behavior. Then come in and change both settings. I will bet ya money the effect on behavior of both settings together is different from the behavior exhibited during their single setting laps, not what you'll expect. They will not be adding their effects but multiplying them. You dig?

Please take the time to read around the various thread and topic posted up here, as a very large number of us are fully aware that set-up and the various settings have a related effect and that changes in that manner you mention can happen. Once again I actually take the time to discuss this very area in the guides.

Got a Q for ya (Scuff, you can play if you want): what KIND of spring-damper set-up is most useful for maximizing the effects of downforce? See, DF's effects on suspension are more readily apparent, but let's look at it the other way. Not a trick Q; I do enjoy these exchanges of info and insight.

Once again the name is Scaff, I can only assume that you are deliberately spelling it incorrectly; maybe you are attempting to provoke a reaction?

As to what kind of spring-damper set-up would aid downforce, well quite simply the information you have given is far to limited to answer that. What level of downforce are we talking about here, at what speeds would be operating, what is the car, its drivetrain, the track? All these questions would have an impact on how the aero vs suspension balance would need to be looked at, and even then testing would be needed to check the validity of the results and the suitability for the driver and their own particular style and preferences.

As a very, very general guide the higher the level of downforce and the greater the speed, then the greater the additional 'load' generated and the stiffer the spring and damper set-up would need to be. That is however a very general guide as I have already said.


I would however now ask that you take the time to look around GT Planet and review the AUP and take a look at the level and quality of posts we look for from members, as currently both you general attitude and posting quality is below that which would be expected.

Thanks

Scaff

 

[sucahyo]

Now you, Suc, when I say 53 in front feels like 53 in rear... My bad. I mean, "If you dial in 53 DF in front, And Also dial it in in the rear, they will both be subject to the same forces." Can you dig it? I most definitely did NOT mean, "If you set it in front the rear will feel it too!" Got it?

I see. The way I see downforce setting, if the car have downforce value of 25/30 then in my mind I imagine the car has total downforce value of:

x+25 / y+30

where x and y is stock downforce.

We just met. I don't know what your agenda is here. Mine is the discussion and disemination of GOOD, PROVEN, USEFUL, 411 about the GT car sim game series. Since I can't see you I didn't know if you're just picking fights over semantics or if my words were not clear enuff. What set me off is: there is nothing I hate more than being misinterpreted. Well, if some1 said I gave out bad info, that I'f hate more.

I am sorry, I don't intent to hurt your feeling. I don't intent to pick fight over semantic.

While you're doing this you will - of course - be taking notes on how the setting affects car behavior. Then come in and change both settings. I will bet ya money the effect on behavior of both settings together is different from the behavior exhibited during their single setting laps, not what you'll expect. They will not be adding their effects but multiplying them. You dig?

I don't understand the "not be adding their effects but multiplying them" part.

 

[Duke]

Hey scuff, if you're the mod, or run this hootenanny, feel free to do whatever strokes your ego. Like you need the prompting... Ha! You seem to have (been allowed to?) set up ya own lil altar to yourself here. I can see the draw, but it feels kinda creepy. Again, if you're the owner, hey, it's your show. As long as you ain't president of SONY and can actively bar me from playing, feel free to float ya boat.

But howbout: If you're the owner, you should be the 1 person most welcoming of different views and challenges. Knowledge not challenged becomes dogma; just "the way it is, though no1 remembers why anymore".And anyway, if you are the owner and you set this site up just to lord it over every1, I just as well rather keep away.

I hardly think that Scaff has done anything to lord anything over anyone, other than to fulfill his duty as moderator to enforce the rules.

You've been politely asked (by Scaff) to use proper grammar and to avoid insulting other members. Now you're being told to do so (by me). No need to involve the owner of the site - since he's already invited us to help uphold the quality of this forum, and given us the tools to do so.

If you think that Scaff is on an ego rip, I'd like to point out that he has disagreed on numerous occasions with Sucahyo, yet he's doing his job by protecting Sucahyo's rights here against your insults.

But you gohed n write ya lil head off. Seems to do you good, huh?

If you'd bother to read Scaff's guides instead of dismissing them as an ego trip, you'd find that he's done a huge amount of careful research into GT4 settings, and he's combined it with plain discussion of both real effects and the theory behind it.

I do enjoy these exchanges of info and insight.

We do too, or else we wouldn't bother to be here. But you need to make sure that what you exchange is information, not slang, insults, and trash talk.

Understood?

 

[Scaff]

I don't understand the "not be adding their effects but multiplying them" part.

I believe that what is being said here is that (as a very general example) while increasing the front stabiliser value increases a cars tendency to understeer by a factor of 1 (just a figure to illustrate the point) and increasing the front spring rate also increases a cars tendency to understeer by a factor of 1 (again just an illustrative figure), using both together will not always give an increase of 2. It could (depending on the car, track and other factors) increase it by 4 or 6 or 8.

It goes back to something I have always maintained, and that is 'formula' tuning is not a sound approach and can lead to so very unpredictable results.

Regards

Scaff

 

[sucahyo]

I see.

A bit interested in this I search around and find this:

Aerodynamic downforce is simply lift, but in the opposite direction. As Danger said, it's a way to push the car down onto the road in order to maintain grip.

A very useful equation (which you should have seen before) is:

L = 0.5 * Cl * A * r * V^2

Where L is lift (or in your case, downforce), Cl the lift coefficient, A the area of the body in question, r the air density, and V the velocity of the fluid flow.

Sorry for the lack of fancy text.

and

% VEHICLE DATA
M = 610; % weight [kg]
CdS = 1.035; % coefficient of drag * reference surface [m2]
ClS = 2.325; % coefficient of downforce * reference surface [m2]
h_cg = 0.25; % cg height [m]
W_d = 0.43; % percentage of weight at the front
W_b = 3; % wheelbase [m]
W_bf = W_b *(1-W_d); % distance front axle - cg [m]
W_br = W_b - W_bf; % distance rear axle - cg [m]
r = 0.33; % wheel radius [m]
f = 0.01; % rolling resistance coefficient (assuming drag force = M * f)
mu_lat_r = 1; % rear lateral friction coefficient
mu_lat_f = 1; % front laterl friction coefficient

% CONSTANTS
g=9.81;
rho = 1.22; % air density

% engine power curve X = rpm, Y = power [kW]
X = [13500,14500:500:18500];
Y = [452,485,517,536,548,558,570,580,588,593];
max_v = (2*max(Y)*1000/(rho*CdS))^(1/3); % theoretical max speed considering only aero drag

R = 500; % m radius



% nasty rearranged equation to find max cornering speed with aero downforce
top_bit = g*(W_br*musf+W_bf*musr)/W_b
long_bit = 0.5*rho*ClS*(W_br*musf+W_bf*musr)/(M*W_b)
bottom_bit = 1/R - long_bit % if long_bit > 1/R we end up with sqrt of negative number
% fraction = top_bit/bottom_bit
% spd = sqrt(fraction)

if long_bit > 1/R
disp('negative square route: flat out corner, treat as straight')
else
fraction = top_bit/bottom_bit
spd = sqrt(fraction)
if spd>max_v
disp('potential speed greater than max: flat out corner, treat as straight')
end
end

%
% if we have a flat out corner, we can treat it as a straight,
% so recalculate that sector as straight with length = original corner length
%
% if this means we have a straight followed by a straight, they can be combined to make one long straight
%
% if it is not a flat out corner then we can use the spd value to calculate time for that corner as before
% time = distance/speed
% for two consecutive corners we will still have to put up with a step change in vehicle speed.
%
% with corner speeds set we have entry & exit speeds for the straights.

 

[cigano]

I'm not about to try to out-write you guys. I don't have to like you to share a board, but if you guys must and you find me objectionable, do what you will, in good spirits.

So from now on I'll just say what I think and go, b4 some1 says something stupid. Hey, me included. Happy?

aero and springs
<i>"As a very, very general guide the higher the level of downforce and the greater the speed, then the greater the additional 'load' generated and the stiffer the spring and damper set-up would need to be. That is however a very general guide as I have already said."</i> - Scaff

Well, then I hafta ask - like a barista - what style you use to get the fastest laps outta your tires? You like all 4 to spread the load evenly (can we call this hard springs?) or you like the tires in question - say the 1s on the outside of a turn - to load up? Oh, and, can we call this soft springs? The really important question is, of course: why....

I am going back to the hard/soft divide, but it'll all tie in. I don't have any kinda theory for any1 to test, I just been on a very weard testing trip with springs/dampers, n I haven't finished. It started with trying to win Ex/Real Track tours/the Ring on a 787B.

I'll say this, soft dampers let me "hear" the car better, springs and DF notwithstanding (to a point).

The Multiplicatin' thing
force vectors are among the things subject to the law of inverse sqares.

<i>Not Duke n Scaff, they're not inverse, they're just... Never mind. at this board, the sweet aroma of humor is quelled by the reek of competition...</i>

Any1 here ever hear of mechanical advantage? Please chime in, I'm not a physicist, don't wanna confuse no1.
For example, axle, handle, mounted perpendicular. Handle, given length. Your hand exerts a force on the end of the handle, causes force - guess what it's called? - to be expressed at axle. Measurable force! For the givens, Boom, a particular result. Sucahyo! Buddy! Guess what happens to that force if we double the length of the handle, and do the same experiment? I see you like to research on ya own. Well, there ya go. I'll be around again soon.

PS: You find out about that 1, try this: what if now the axle - mounted parallel to ground - moves up and down while you move the handle? Does the RATE of movement affect how much force reaches the axle?

 

[HYBRIDLVR]

You can learn a lot here by concentrating on GT instead of even slightly taking shots at the staff, Everyone is eager to help but you got to focus on one or the other, One will give you lots of information, The other will cause you to dissappear, Me personally want you to stay and will love to help you out!
*Cheers*

 

[Scaff]

I'm not about to try to out-write you guys. I don't have to like you to share a board, but if you guys must and you find me objectionable, do what you will, in good spirits.

So from now on I'll just say what I think and go, b4 some1 says something stupid. Hey, me included. Happy?

As long as you follow the AUP, are polite in how you deal with other members and post in English without the use fo text speak and abreviations then no one has a problem. Unfortunately to date you track record in these areas in not good, but that I have addressed in seperate PM.

aero and springs
<i>"As a very, very general guide the higher the level of downforce and the greater the speed, then the greater the additional 'load' generated and the stiffer the spring and damper set-up would need to be. That is however a very general guide as I have already said."</i> - Scaff

Well, then I hafta ask - like a barista - what style you use to get the fastest laps outta your tires? You like all 4 to spread the load evenly (can we call this hard springs?) or you like the tires in question - say the 1s on the outside of a turn - to load up? Oh, and, can we call this soft springs? The really important question is, of course: why...

I'm not 100% clear about exactly what you are trying to say here (mainly due to your rather unique and potentially very confusing posting style).

Spreading the load = hard springs?
Bias to the outside = soft springs?

Could you please explain (in plain English) you exact thinking behind this, are we talking about soft or hard all over or softer/harder at one end of the car? Its certainly not clear from what you have posted and clarification is rather important to be able to discuss this, I owuld suggest having a quick read of the stickied post on spring rates and weight transfer by Greyout first.

https://www.gtplanet.net/forum/showthread.php?t=57625

I am going back to the hard/soft divide, but it'll all tie in. I don't have any kinda theory for any1 to test, I just been on a very weard testing trip with springs/dampers, n I haven't finished. It started with trying to win Ex/Real Track tours/the Ring on a 787B.

I'll say this, soft dampers let me "hear" the car better, springs and DF notwithstanding (to a point).

The Multiplicatin' thing
force vectors are among the things subject to the law of inverse sqares.

<i>Not Duke n Scaff, they're not inverse, they're just... Never mind. at this board, the sweet aroma of humor is quelled by the reek of competition...</i>

Any1 here ever hear of mechanical advantage? Please chime in, I'm not a physicist, don't wanna confuse no1.
For example, axle, handle, mounted perpendicular. Handle, given length. Your hand exerts a force on the end of the handle, causes force - guess what it's called? - to be expressed at axle. Measurable force! For the givens, Boom, a particular result. Sucahyo! Buddy! Guess what happens to that force if we double the length of the handle, and do the same experiment? I see you like to research on ya own. Well, there ya go. I'll be around again soon.

PS: You find out about that 1, try this: what if now the axle - mounted parallel to ground - moves up and down while you move the handle? Does the RATE of movement affect how much force reaches the axle?

Well if you "don't wanna confuse no1." (sic) then actually write in a manner that is understandable. I'm sorry to keep going on about this, but it is a clear AUP violation and we have a lot of members for whom English is a second language and quite frankly posting like this is not going to help.

I mean I have taught vehicle dynamics in the motor industry and have a very good grasp of the physics involved and I must admit that I'm not 100% sure what you are getting at here.

Regards

Scaff

 

[cigano]

Ah, You Taught. Explains a lot.
While I'm still here: Hard or soft all over, in a general sense. 4.8 - 3.6 is strcitly speaking "one more than the other", but they both still soft in general. 15.3 - 12.5 is - significantly, true - different but still both are pretty hard in themselves.

Now, now puhleeeze: which way you swing; you load or split?

PS: and why....

 

[Scaff]

Ah, You Taught. Explains a lot.

(Not rising to the bait) I still teach, just moved areas, its now more systems, management and aftersales training with a degree of training consultancy thrown in for good measure (still in the motor industry).

While I'm still here: Hard or soft all over, in a general sense. 4.8 - 3.6 is strcitly speaking "one more than the other", but they both still soft in general. 15.3 - 12.5 is - significantly, true - different but still both are pretty hard in themselves.

Now, now puhleeeze: which way you swing; you load or split?

PS: and why....

I honestly do not have a pre-set preference for any set way of tuning, it depends on the car and the track, I always drive the car at the track and work from its basic set-up. I like to go as firm as the situation will allow, but too far either way will always lead to one problem or another.

Tuning in GT4 does (to a much lesser degree) mirror the real world here, its always a series of compromises, a car set-up ideally for one corner on a track will be wrong for another corner. Its about knowing the car and its strengths and weaknesses and looking at the track, it conditions and which corners are the most important.

As far as spring rates go, well soft or hard are relative terms, a spring rate of say 7 kgt/mm will feel soft in a car with a curb weight of 2,000 kilos, but the same spring in a car weighing 500 kilos will feel very hard. With a track like Grand Valley you can run a hard set-up (for the cars weight) quite easily and it will benefit you; but a softer set-up (again judged by the car in question) will be needed on a track such as Deep Forest or the 'ring.

In regard to if a softer or harder set-up will change how load is split between corners, well if the suspension is softened or firmed up equally all around then the changes in transfer to individual corners in almost negligible. A softer car will roll more, but roll is caused by load transfer, in simple terms a car with solid suspension will transfer load the same as a car with soft suspension, as long as the changes are applied to each corner or end equally.

Corner split in load transfer comes into play when you change the balance between the ends of the car itself, in basic terms (and I am being very basic here) softening one end of the car will give a more equal split between the tyres at that end and with the load more equally shared they will be able to better grip. However this is all gone into in more detail in the thread by Greyout I linked to in my last post.

Which leads us back to the question of which direction to head in, well on the face of it soft would seem better as it allows better share the load, but go to soft and you can run into problems. Including (but not limited to) teh risk of increased roll allowing the car to bottom out, which would require a higher ride height, which would increase load transfer and that brings us back to square one.

As I have always maintained all tuning is about the relationship between everyone of the settings involved, the car and its natural balance, the track and its demands, the driver and their preferences. However its also a matter of compromise, what you gain in one area you almost certainly lose in another.

I do have to say, and you might not like it, but I cover all of this and a hell of a lot more in the two tuning guides I put together. You may dismiss them without a look, but you certainly would have a better understanding of how I tune and how I suggest going about tuning if you took the time to actually read them. I don't tell anyone how they 'must' tune or use a set formula (in fact I personally don't support approaches of this nature), rather I try and explain what will happen with the overall settings, the front/rear balance and also why something is happening; using lots of GT4 and real world examples, plain English and a lot of diagrams and illustrations.

You may guess that it gets my back up a bit when they are dismissed out of hand, well to be honest yes it does. Over 9 months worth of GT4 testing, years of real world experience and over 40 hours of writing went into them, so if someone dismisses they without (it appears) actually taking the time to read them, well I'm sure you understand why it feels frustrating.


Regards

Scaff

 

[Duke]

Ah, You Taught. Explains a lot.

It's been suggested to you (by other users) that you should stop taking cheap shots at others. You've been asked, and told (by staff) to stop taking cheap shots at others.

NOW STOP IT.

While I'm still here: Hard or soft all over, in a general sense. 4.8 - 3.6 is strcitly speaking "one more than the other", but they both still soft in general. 15.3 - 12.5 is - significantly, true - different but still both are pretty hard in themselves.

Now, now puhleeeze: which way you swing; you load or split?

PS: and why....

English IS my first language, and I'm fairly literate in engineering and vehicle dynamics, and I have to read your posts multiple times in order to figure out what you're trying to say.

And, frankly, given your condescending attitude and your refusal to modify your excessively loose language style, it's just plain not worth the effort.

Now, if you be a good boy and stop being so smug, and stop trying to sneak in shots against other users and staff, then we can skim your rambling yoboy posts and quit caring if you make sense or not. This dialogue will die out because nobody can be bothered with you anymore.

Or you can keep going like you are, and collect enough infractions that the dialogue is killed because you are banned.

A third possibility exists, if YOU care to choose it: you can grow up, make clear, sensible posts that don't sound like you're a goombah from the Bronx, and lay off the posturing and cheapshots. In this case, the dialogue thrives, and we all learn something from each other.

It's up to you. But the situation will change from here on out, one way or the other. Understood?

 

[Kris Radke]

(Not rising to the bait) I still teach, just moved areas, its now more systems, management and aftersales training with a degree of training consultancy thrown in for good measure (still in the motor industry).




I honestly do not have a pre-set preference for any set way of tuning, it depends on the car and the track, I always drive the car at the track and work from its basic set-up. I like to go as firm as the situation will allow, but too far either way will always lead to one problem or another.

Tuning in GT4 does (to a much lesser degree) mirror the real world here, its always a series of compromises, a car set-up ideally for one corner on a track will be wrong for another corner. Its about knowing the car and its strengths and weaknesses and looking at the track, it conditions and which corners are the most important.

As far as spring rates go, well soft or hard are relative terms, a spring rate of say 7 kgt/mm will feel soft in a car with a curb weight of 2,000 kilos, but the same spring in a car weighing 500 kilos will feel very hard. With a track like Grand Valley you can run a hard set-up (for the cars weight) quite easily and it will benefit you; but a softer set-up (again judged by the car in question) will be needed on a track such as Deep Forest or the 'ring.

In regard to if a softer or harder set-up will change how load is split between corners, well if the suspension is softened or firmed up equally all around then the changes in transfer to individual corners in almost negligible. A softer car will roll more, but roll is caused by load transfer, in simple terms a car with solid suspension will transfer load the same as a car with soft suspension, as long as the changes are applied to each corner or end equally.

Corner split in load transfer comes into play when you change the balance between the ends of the car itself, in basic terms (and I am being very basic here) softening one end of the car will give a more equal split between the tyres at that end and with the load more equally shared they will be able to better grip. However this is all gone into in more detail in the thread by Greyout I linked to in my last post.

Which leads us back to the question of which direction to head in, well on the face of it soft would seem better as it allows better share the load, but go to soft and you can run into problems. Including (but not limited to) teh risk of increased roll allowing the car to bottom out, which would require a higher ride height, which would increase load transfer and that brings us back to square one.

As I have always maintained all tuning is about the relationship between everyone of the settings involved, the car and its natural balance, the track and its demands, the driver and their preferences. However its also a matter of compromise, what you gain in one area you almost certainly lose in another.

I do have to say, and you might not like it, but I cover all of this and a hell of a lot more in the two tuning guides I put together. You may dismiss them without a look, but you certainly would have a better understanding of how I tune and how I suggest going about tuning if you took the time to actually read them. I don't tell anyone how they 'must' tune or use a set formula (in fact I personally don't support approaches of this nature), rather I try and explain what will happen with the overall settings, the front/rear balance and also why something is happening; using lots of GT4 and real world examples, plain English and a lot of diagrams and illustrations.

You may guess that it gets my back up a bit when they are dismissed out of hand, well to be honest yes it does. Over 9 months worth of GT4 testing, years of real world experience and over 40 hours of writing went into them, so if someone dismisses they without (it appears) actually taking the time to read them, well I'm sure you understand why it feels frustrating.


Regards

Scaff

Hey Scaff, when are you going to stop tootin' your own horn?

Sucayho, I would highly recommend downloading the document that Scaff referred to earlier in this thread. Handling, and all of the contributing factors isn't something you are going to master overnight. I've been reading and re-reading Scaffs' manual for weeks now, and I just now am starting to understand what parameters to adjust when x characteristic is exhibited. And I don't always get it right either. The relationship and phenomenon of over and understeering is not one that you are likely to understand quickly either. Diagnosing over or under steer takes practice and thought.

Is the car oversteering in a long-steady sweeper? Or when transitioning into or out of a corner? Or how about when applying throttle or braking? You have to understand WHEN and WHERE over and understeer are occuring BEFORE you attempt to adjust anything, or you will just be 'spinning your wheels'.

Like I said, it will take a LOT of reading and COMPREHENSION to figure out how to correctly tune a car. I like to tune a car to make it easier to drive, rather than faster. Fun is the name of the game for me, and a touchy on the edge race car isn't my idea of fun.

Scaffs' manual is a GREAT starting point.👍

 

[sucahyo]

Like I said, it will take a LOT of reading and COMPREHENSION to figure out how to correctly tune a car. I like to tune a car to make it easier to drive, rather than faster. Fun is the name of the game for me, and a touchy on the edge race car isn't my idea of fun.

Scaffs' manual is a GREAT starting point.👍

Thanks for giving information, but I already discuss many thing related to what inside those guide with Scaff. Although in the end, I still stubborn with my own opinion .