Lift-off Oversteer

[lbpomg95]

lift-off oversteer

Not sure if anyone's already said (tl:dr) but ways of reducing lift-off oversteer I've found helpful are;
Increasing negative front toe
Increasing deceleration sensitivity
Adding ballast to the front
Lowered brake balance both ends
Depending on the tyres I've found that stiffening the front springs (and the rear to a lesser extent) seem to help, though on less grippy tyres this seems to reduce overall turning ability.

 

[332i]

Yeah, I just don't touch the springs, because once the car is balanced, it is balanced and I'm setting the cars up for max tire traction and consistent entries. As I've said and this goes for IRL too...springs are solely for supporting vehicle weight. When I got to the nurb nord or 24hr, I change the rear sway and rebound. Nothing else. Idk whatever works best for each person.

 

[DolHaus]

Yeah, I just don't touch the springs, because once the car is balanced, it is balanced and I'm setting the cars up for max tire traction and consistent entries. As I've said and this goes for IRL too...springs are solely for supporting vehicle weight. When I got to the nurb nord or 24hr, I change the rear sway and rebound. Nothing else. Idk whatever works best for each person.

I agree that changing the spring rates and ride height should be the absolute last resort in finding a solution. I wouldn't say never change them but instead only do so if a solution can't be found by making alterations to the alignment, dampers and/or ARBs 👍

 

[KniX]

You would take a tune for a track like Silverstone GP to Nurburgring without touching the ride height or springs?

As I've said and this goes for IRL too...springs are solely for supporting vehicle weight.

Yeah while the car is going around the track, accelerating, braking and cornering. Support the weight dynamically.

Not nearly as simple as it appears you're making it out to be.

A set up perfectly Balanced for Silverstone GP shouldn't be perfectly balanced for the Nurburgring. One track or the other is compromised even if slightly. Silverstone GP is very smooth and relatively flat, it allows a very low ride height & very stiff spring, while Nurburgring is the Polar opposite and will not allow a ride height set for as low as it can go or for as stiff as it can go on Silverstone GP.

 

[Mustangmiha]

What I do on almost all FR/MR cars is set brakes 10/10, even when braking in the corners and there's no oversteer at all, you can brake much later and still swiftly go through the corners but you only have to brake before the corner. Set LSD for torq and acc 5 to 15, deacc 20 and that's about it. Tinker a little with the suspension and you'll have your car in control in no time. And of course, don't leave the tarmac because the grass affects your tyres.

 

[332i]

You would take a tune for a track like Silverstone GP to Nurburgring without touching the ride height or springs?



Yeah while the car is going around the track, accelerating, braking and cornering. Support the weight dynamically.

Not nearly as simple as it appears you're making it out to be.

A set up perfectly Balanced for Silverstone GP shouldn't be perfectly balanced for the Nurburgring. One track or the other is compromised even if slightly. Silverstone GP is very smooth and relatively flat, it allows a very low ride height & very stiff spring, while Nurburgring is the Polar opposite and will not allow a ride height set for as low as it can go or for as stiff as it can go on Silverstone GP.

Not as simple as I am making it? That is the purpose of a spring in a suspension system. After that, you have two options - whether they are linear or progressive. I'm not simplifying it. That is the textbook reasoning for springs and I'm stating it as such, because it simply isn't worth complicating or delving too far into on here. People confuse the purposes of shocks, struts and springs between each other as it is.

You don't just go changing spring rates and ride heights, simply because a track surface will allow you to or because you can. Like I said, whatever works for you.

 

[AHR3EX]

Not as simple as I am making it? That is the purpose of a spring in a suspension system. After that, you have two options - whether they are linear or progressive. I'm not simplifying it. That is the textbook reasoning for springs and I'm stating it as such, because it simply isn't worth complicating or delving too far into on here. People confuse the purposes of shocks, struts and springs between each other as it is.

You don't just go changing spring rates and ride heights, simply because a track surface will allow you to or because you can. Like I said, whatever works for you.

I like higher frequencies for smooth surfaces & Lower frequencies for rougher tracks

 

[Scaff]

As I've said and this goes for IRL too...springs are solely for supporting vehicle weight.

No they are not.

Springs have a massive roll to play in setting and controlling the cornering balance of a car, not to mention the degree of roll that the car will be subject to under longitudinal and latitudinal load transfer, note that this will not change the amount of load transfer - but it does change how that load is distributed across an axle and how much the car will roll/dive/squat under that load transfer.

That's rather a lot more than 'solely for supporting the vehicle weight'.

 

[Motor City Hami]

No they are not.

Springs have a massive roll to play in setting and controlling the cornering balance of a car, not to mention the degree of roll that the car will be subject to under longitudinal and latitudinal load transfer, note that this will not change the amount of load transfer - but it does change how that load is distributed across an axle and how much the car will roll/dive/squat under that load transfer.

That's rather a lot more than 'solely for supporting the vehicle weight'.

If springs were simply to hold the car up then I guess it was pretty stupid of me to carry four sets of springs with me when I raced a Honda Civic in real life.

 

[DolHaus]

If springs were simply to hold the car up then I guess it was pretty stupid of me to carry four sets of springs with me when I raced a Honda Civic in real life.

I though you just liked showing off

 

[Ridox2JZGTE]

I like higher frequencies for smooth surfaces & Lower frequencies for rougher tracks

Frequency What sort of frequency ?

 

[AHR3EX]

Frequency What sort of frequency ?

"""We choose our springs to control the tyre - to maintain grip, maintain tyre contact with the road. The spring works together with the shock absorber in this role. In reality, analysis is complex, requiring expensive equipment, eg the 7-post rig. So we must choose our preferred stiffness based on experience and testing.

Having determined a reasonable suspension stiffness for grip, relative front to rear stiffness can be modified for balance (understeer or oversteer). Further stiffening of the suspension may be required to control overall roll, although this will normally be achieved with a combination of anti-roll bars, shocks and springs, rather than the springs alone. We need to know what the suspension stiffness is, as a first step in calculating roll resistance.

Spring Frequency - Compare Stiffness of the Set Up Between Race Cars

The most usefull measure of suspension stiffness is the spring frequency. It is directly comparable between all race cars. We can take our experience with one race car and use it to help choose spring stiffness for another. For instance, we find that small sedans and production sports cars around 1000kgs, without aero devices, will work best around 120 to 130 cycles per minute, running on Dot racing tyres. This is a lot stiffer than road car springs, where spring frequencies might be around 80 to 100 cpm. Other considerations might require us to run stiffer again. But 120 to 130 is what we'd like to run for maximum grip.

Heavy sedans might run lower spring frequencies, and light open wheelers might run higher spring frequencies. The controlling factor here is that the heavy vehicle requires greater increase in spring rate to achieve a given spring frequency increase. """

http://www.smithees-racetech.com.au/performancefactors.html

 

[Ridox2JZGTE]

Oh, that Already use that in some extent when building replicas ( adapting real life springs based on similar approach - when I have complete data like wheel rate, motion ratio and suspension frequency ) and I found they work well in GT6, behave as expected Haven't found one that don't work, even my Gr4 Stratos seems to work well now

 

[AHR3EX]

If I was a budget racer I would try to find a spring that would be generally good at the places I go racing, and try to get the most out of one set of springs with the alignment, but if you can afford it find the best springs for every location. At least have a second set for the wet if you race wet and dry.

 

[Motor City Hami]

If I was a budget racer I would try to find a spring that would be generally good at the places I go racing, and try to get the most out of one set of springs with the alignment, but if you can afford it find the best springs for every location. At least have a second set for the wet if you race wet and dry.

Completely agree. The class that I race now, Spec Miata, has mandated that we all use the same spring rate (and shocks). It does help keep cost down but forces us to look elsewhere for handling improvements.

As for rain racing, the biggest issue is where I live is that rain often comes and goes on a rainy day. You are most often on grid before you really know if you needed rain tires or slicks. I have been caught on slicks in the rain around 15 times in my racing career. I have a crew guy standing on grid with me with wrenches to remove the rear sway bar if we are on slicks and it starts to sprinkle.

 

[AHR3EX]

Completely agree. The class that I race now, Spec Miata, has mandated that we all use the same spring rate (and shocks). It does help keep cost down but forces us to look elsewhere for handling improvements.

As for rain racing, the biggest issue is where I live is that rain often comes and goes on a rainy day. You are most often on grid before you really know if you needed rain tires or slicks. I have been caught on slicks in the rain around 15 times in my racing career. I have a crew guy standing on grid with me with wrenches to remove the rear sway bar if we are on slicks and it starts to sprinkle.

Getting caught on a set up that would of been great for the conditions 15min ago but not so good while you sit on the grid and having no choice but to press on is a side of racing many gamers are unaware of. The worst is making the choice to pit then conditions change soon after you leave the pits. "Thats Racing" as they say.

Yanking the rear bar is a smart move in that situation

 

[super_gt]

Is there a sort of 'rule of thumb' for settings to reduce or eliminate this?

It may sound weird but try to put tires with less grip only in front.

 

[332i]

No they are not.

Springs have a massive roll to play in setting and controlling the cornering balance of a car, not to mention the degree of roll that the car will be subject to under longitudinal and latitudinal load transfer, note that this will not change the amount of load transfer - but it does change how that load is distributed across an axle and how much the car will roll/dive/squat under that load transfer.

That's rather a lot more than 'solely for supporting the vehicle weight'.

And these 'rolls they play" are exactly what they do correctly when vehicle weight is properly supported. If it is not, then you obviously get too much or little of any sort of pitch. Everything you just listed is an instance in which the springs are at work doing what they are supposed to - supporting the weight of the vehicle. Otherwise, it would do all of which you describe in a different manner...because the vehicle is not being supported as well or the same. Seems you deduced that just as motorcity did. Controlling corner balance? That IS what supporting vehicle weight is, just at a different physical state - in motion. You're picturing mine as static. Controlling how much something rolls/dives/squats (more simply - pitch)...IS supporting vehicle weight, dude. Think that through. If you weren't supporting vehicle weight, you would get a lot of unwanted pitch and quite possibly compression. Ideally, you want nearly zero pitch, which is why FRIC systems exist in the world (which exists in many forms).

 

[Scaff]

And these 'rolls they play" are exactly what they do correctly when vehicle weight is properly supported. If it is not, then you obviously get too much or little of any sort of pitch. Everything you just listed is an instance in which the springs are at work doing what they are supposed to - supporting the weight of the vehicle. Otherwise, it would do all of which you describe in a different manner...because the vehicle is not being supported as well or the same. Seems you deduced that just as motorcity did. Controlling corner balance? That IS what supporting vehicle weight is, just at a different physical state - in motion. You're picturing mine as static. Controlling how much something rolls/dives/squats (more simply - pitch)...IS supporting vehicle weight, dude. Think that through. If you weren't supporting vehicle weight, you would get a lot of unwanted pitch and quite possibly compression. Ideally, you want nearly zero pitch, which is why FRIC systems exist in the world (which exists in many forms).

Only if you wish to use the term 'supported' in a range of ways that no one in the motor industry does (well not in my twenty years).

Oh and your still wrong as a vehicles weight and its load (and how they transfer around) are very different things (unless you live in a world in which lift and downforce don't exist). Supporting is totally and utterly the wrong word to be using for a body in motion (which is why its not used), transfer is the correct term and weight should be load.


Now aside from the misuse of the word that still fails to explain exactly why you then feel it doesn't need to be adjusted?

 

[332i]

If springs were simply to hold the car up then I guess it was pretty stupid of me to carry four sets of springs with me when I raced a Honda Civic in real life.

Interesting that you had nothing to say about and even agreed with what I've said about suspensions ITT. In fact you point that out yourself. You are quite transparent.

Only if you wish to use the term 'supported' in a range of ways that no one in the motor industry does (well not in my twenty years).

Oh and your still wrong as a vehicles weight and its load (and how they transfer around) are very different things (unless you live in a world in which lift and downforce don't exist). Supporting is totally and utterly the wrong word to be using for a body in motion (which is why its not used), transfer is the correct term and weight should be load.


Now aside from the misuse of the word that still fails to explain exactly why you then feel it doesn't need to be adjusted?

Saw "in the motor industry" and stopped reading. Say or describe it however you want. I can see you think you know everything and you're welcome to keep that up (in the motor industry). Idk what you do, but it has nothing to do with suspension systems.

Go reading about what rolls springs play and what rolls dampers play in a suspension system. This is silly. These is extremely remedial stuff.

 

[Scaff]

Saw "in the motor industry" and stopped reading. Say or describe it however you want.

No I simply use the terms that are common to the industry to avoid confusion.

I can see you think you know everything and you're welcome to keep that up (in the motor industry). Idk what you do, but it has nothing to do with suspension systems.

You know how I think and what my background is in specific detail? How exactly do you do that, because I hate to tell you that you are wrong on both counts.

To be blunt the attitude and dismissive nature will not stand you well here at GT Planet.

I suspect the real reason is that you don't wish to answer the question I asked.

Oh and stop double posting.

I see you added:

Go reading about what rolls springs play and what rolls dampers play in a suspension system. This is silly. These is extremely remedial stuff.

Which would you like me to re-read?

Brian Beckman's Physics of Racing
The set-up manual from the Skip Barber racing School
The Porsche driving manual
Alan Stainforth's Race and Rally car source book

Or one of the many others I own and have used in the past to develop training material?

Maybe you could explain why the Skip Barber school (as well as all the others) uses the terms load and transfer, rather than just describing it as supporting the weight'?

 

[332i]

No I simply use the terms that are common to the industry to avoid confusion.



You know how I think and what my background is in specific detail? How exactly do you do that, because I hate to tell you that you are wrong on both counts.

To be blunt the attitude and dismissive nature will not stand you well here at GT Planet. My blunt and dismissive nature? I'm sorry,

I suspect the real reason is that you don't wish to answer the question I asked.

Oh and stop double posting.

What? That's exactly what I didn't say - I said idk what you do in the motor industry. I guess you could say I told you what I don't think you do lol (anything with suspension systems). However you wish to see it. My blunt and dismissive nature? I'm not, nor is anyone else here to humour you. I'm sorry, do you dislike someone cutting to the chase and their lack of concern for something that came from you?

I don't have to answer anything of you. I've said what springs do and you can go read about them to your hearts content. In racing (and this is a racing game), springs are solely meant for supporting vehicle weight. Dampers control their natural characteristics. That's why dampers are valved to work with specific rates, with linear or progressive rates, etc.

I'm not breaking the AUP or whatnot by 1) correcting you, after your failed in attempt to correct me lol or dismissing something that is wrong and doesn't make sense.

I already answered your question. You just want to keep hearing your own answer. Your gripe with me exists because I answered your questioned before you asked it. That's why you posted - to tell me I am wrong. Then you tried to correct me and you're just going to get the same answer.

 

[Scaff]

What? That's exactly what I didn't say - I said idk what you do in the motor industry. I guess you could say I told you what I don't think you do lol (anything with suspension systems). However you wish to see it. My blunt and dismissive nature? I'm not, nor is anyone else here to humour you. I'm sorry, do you dislike someone cutting to the chase and their lack of concern for something that came from you?

Really you said that you know I have done nothing with suspension systems?

Prove it.

I don't have to answer anything of you.

You don't but in refusing to do so you undermine what little credibility you have.

I've said what springs do and you can go read about them to your hearts content. In racing (and this is a racing game), springs are solely meant for supporting vehicle weight.

Then you will have no problem proving that. After all I have already shown that a rather well established racing school disagrees with you.

Dampers control their natural characteristics. That's why dampers are valved to work with specific rates, with linear or progressive rates, etc.

And springs are available in different rates for fun?

 

[AHR3EX]

I don't have to answer anything of you. I've said what springs do and you can go read about them to your hearts content. In racing (and this is a racing game), springs are solely meant for supporting vehicle weight.

Stock spring support the vehicle weight...........


A track with an average speed of 75mph will not have the same loads as a track averaging 125mph. The loads will be different, the weight seen on the springs different, how could the same spring be perfectly balance with 2 different loads?



.

 

[332i]

No I simply use the terms that are common to the industry to avoid confusion.



You know how I think and what my background is in specific detail? How exactly do you do that, because I hate to tell you that you are wrong on both counts.

To be blunt the attitude and dismissive nature will not stand you well here at GT Planet.

I suspect the real reason is that you don't wish to answer the question I asked.

Oh and stop double posting.

I see you added:

Which would you like me to re-read?

Brian Beckman's Physics of Racing
The set-up manual from the Skip Barber racing School
The Porsche driving manual
Alan Stainforth's Race and Rally car source book

View attachment 256096

Or one of the many others I own and have used in the past to develop training material?

Maybe you could explain why the Skip Barber school (as well as all the others) uses the terms load and transfer, rather than just describing it as supporting the weight'?

View attachment 256098

You're flipping through books that are written to explain something to someone who is driving the car. You're not reading an engineering book. Those are basic info books. Are you for real? You cant learn technique for driving via reading, either. That's like explaining what a color looks like.

 

[Scaff]

Stock spring support the vehicle weight

.

And even they will have been selected and set-up to ensure that they achieve the correct dynamic balance.

You're flipping through books that are written to explain something to someone who is driving the car. You're not reading an engineering book. Those are basic info books. Are you for real? You cant learn technique for driving via reading, either. That's like explaining what a color looks like.

No they are not, which quite clearly shows that you have not read any of them.

But if you want one that goes into a huge level of detail....

http://phors.locost7.info/contents.htm

...knock yourself out, its an on-line resource so you have no excuse at all.

Or would you like me to cite Milliken & Milliken? My copy of that is electronic (from the SME), but I can certainly give you page by page if required.

From p389....

...notice the use of 'load' and 'transfer' and springs being used to adjust them.

Basic info, seriously you have no idea what you are going on about, but I await your sources with interest.

 

[332i]

Stock spring support the vehicle weight...........


A track with an average speed of 75mph will not have the same loads as a track averaging 125mph. The loads will be different, the weight seen on the springs different, how could the same spring be perfectly balance with 2 different loads?



.

I guess it is a good thing that there are maybe another component or two that react to and deal with load, other than springs, right? They may be two different loads, but the proportions are the same, being that scoring rates are ratios. Thanks, though.

We're not arguing ideal springs rates. It seems you're headed in that direction.

And even they will have been selected and set-up to ensure that they achieve the correct dynamic balance.



No they are not, which quite clearly shows that you have not read any of them.

But if you want one that goes into a huge level of detail....

http://phors.locost7.info/contents.htm

...knock yourself out, its an on-line resource so you have no excuse at all.

Or would you like me to cite Milliken & Milliken? My copy of that is electronic (from the SME), but I can certainly give you page by page if required.

Basic info, seriously you have no idea what you are going on about, but I await your sources with interest.

Idk, dude. I'm looking at the picture and still can't figure out what those books are, other than an auto physics book for laymen, a skip barber booklet (skip barber is down the street (don't give yourself too much credit for picking that specific notebook up lol), a driving technique book and a Porsche book...about driving. Still trying to process these feats I guess.

 

[TenEightyOne]

Idk, dude. I'm looking at the picture and still can't figure out what those books are, other than an auto physics book for laymen, a skip barber booklet (skip barber is down the street (don't give yourself too much credit for picking that specific notebook up lol), a driving technique book and a Porsche book...about driving. Still trying to process these feats I guess.

And your sources are....? Like @Scaff I'm expecting something pretty good if it's better than his link (http://phors.locost7.info/contents.htm)

 

[Scaff]

I guess it is a good thing that there are maybe another component or two that react to and deal with load, other than springs, right?

No one but you has disputed that.

So do you now acknowledge that springs can be used to control load distribution

They may be two different loads, but the proportions are the same, being that scoring rates are ratios. Thanks, though.

What!

We're not arguing ideal springs rates. It seems you're headed in that direction.

No we are not, but you do seem to be in a hurry to avoid discussing the claims you made and change the subject.

Idk, dude. I'm looking at the picture and still can't figure out what those books are, other than an auto physics book for laymen, a skip barber booklet (skip barber is down the street (don't give yourself too much credit for picking that specific notebook up lol), a driving technique book and a Porsche book...about driving. Still trying to process these feats I guess.

So explain how you have dismissed them without ever reading them (275 page booklet - OK)?

Do you dismiss the Beckman link as well? What about Milliken & Milliken? (which would be bizarre as its an industry standard?)

Oh and do not double post again and ditch the attitude and snide comments or you will be getting a time out or a ban (its not as if you haven't been warned numerous times already).

 

[TenEightyOne]

Not as simple as I am making it? That is the purpose of a spring in a suspension system. After that, you have two options - whether they are linear or progressive. I'm not simplifying it. That is the textbook reasoning for springs and I'm stating it as such, because it simply isn't worth complicating or delving too far into on here. People confuse the purposes of shocks, struts and springs between each other as it is.

Which textbook, please?

These is extremely remedial stuff.

Then you shouldn't have a problems.