learning GT4 physics flaw from GPL

sucahyo · Oct 13, 2006

Scaff
You don't think that using this particular controller is part of the problem here?

As far as treating the throttle and/or brakes as an on/off setting, then of course its going to cause problems, by rapidly pressing the button the load is being thrown back and forth (or side to side if its steering) rapidly. The result is that the load is constantly shifting and will make it very difficult to judge what is going on.

What problem? GT4 will behave differently if I treat throttle as on/off setting using wheel? If it is, how different if we see how damper react to that?
I don't make the load constantly shifting, I judge how the car behave while the load shifting in one direction, at power on, power off, and turning. It's like:
Do power off while turning, observe.
Do power on while turning, observe.
Do counter steer, observe.

Scaff
I would strongly recommend upgrading to a DS2 or better still a decent steering wheel and pedal set.

Yes, I want it too. Although not in near future I guess.

Scaff
Load transfer occurs when a cars velocity changes in any direction, so an change in acceleration, braking or steering will result in a transfer of load. The relative force of these actions (in conjunction with the basic layout of the car) will determine the degree of transfer, so the harder you accelerate, brake or steer the greater the load transferred will be.

Ok.

Scaff
So if you are cornering and make slight adjustments of the throttle to trim the line the load transfer changes would be small and the car will remain stable, however if you try and trim the line by switching the throttle on and off repeatedly then the changes would be major and the car more unstable. Its why smooth use of all a cars control are vital to proper control on the limit.

For me, proper control yes, better judgement not always. I prefer to tune at spesific condition, more unstable is what I am looking for when tuning, I do not do this when racing.

I drive DIFFERENTLY at the first stage of tuning. I will purposefully make the car unstable, and force the car to work over it's limit. I am not worying about laptime, I am more concern about how the car handle on it's limit or over it's limit. After I satisfy, I will then drive for fast laptime to see what more I can fix.

Scaff
Now that's quite a change of tune, as I can quite clearly remember you arguing that the use of any camber if a car did not visibly roll was wrong. Many people disagreed with you and you stated that we were wrong, despite real world examples that disputed your claims.

No, not like that. I still believe that visual can be used for tuning camber, still believe that using camber more than roll angle is excessive. It's just that how the car behave when using below or above optimal camber confuse me. Now, if I decide to use camber, I would make sure that camber angle is bellow max roll angle in all corner, or if I tune for drifting, make sure that camber angle always exceed max roll angle in all corner. The car behaviour when roll angle passing camber angle in mid corner make tuning complicated for me.

Scaff
Initial turn-in occurs as you start to turn the wheel and the car starts to turn, it occurs before and (sometimes) at the start of load transfer. It is mainly governed by the front tyre nearest the corner apex; once the load transfer has passed a certain point and the front tyre furthest from the corner apex is handling the majority of the work then we are into true corner entry.

Uh, what is the name of state when load transfer is happening ? turn in is before that, entry is after that?
And do you have some information about damper role during turn in? during entry, and damper role when load transfer happen?

Scaff
Then you are acknowledging that you are not able to read everything that the car is doing.

More like I ignore anything else beside front and rear grip balance.

Scaff
As I've said above this is not a factor of load transfer, as initial turn-in is before the transfer occurs. Its a very short lived state, but very important.

Factors that car govern it are dampers, spring rates, toe, tyre width. Camber does not effect it and stabilisers have little or no effect.

Still not clear. That do not explain why you feel slugish and poor steering steering during turn-in using lower damper value.

I think it's better if we use your way of driving. How the car behaviour change after you put lower front damper on hyundai tiburon at the second hairpin at grand valley when:

"Approaching the corner I will tend to brake hard and early to reduce the speed carried through from the previous section,"

1. I reduce the braking as I begin to turn-in (trail braking. Turn-in is the critical, but short lived period when the front tyre nearest the corner is asked to initiate the cars initial change in direction.

2. As the load begins to shift to the outside of the car I will balance the throttle to maximise the speed I can carry through the corner, using small correction of the throttle and steering to hold the car on the limit of grip.

3. As the corner apex is crossed I gradually and smoothly start to apply the power

4. and unwind the steering lock, as the load transfers to the rear of the car, working to get back on the power as quickly, but smoothly as possible.

If you can, please explain how the car understeer or oversteer.

Scaff
The point I have highlighted in bold is not correct, I certainly do use constant steering and throttle if the corner demands it.

What I mean for condition 2 is when the car not showing any change of behaviour, stable condition. It would be few second after constant steering and constant throttle. Some driving style may never reach condition 2. And I am guessing that gregc never use condition 2 when driving my tiburon. This is not gregc fault, this is more my fault.

Scaff
Its the corner that determines how you need to take it, not the other way around.

I use corner to test my tuning. During testing, I don't care if I end up hitting the wall or thrown to grass. It would be great if there is parking lot or wide flat place in GT4. Or it is exist and I don't know it?

Ebiggs
Sucahyo, I'd suggest giving up at this point.

No, still have something to ask

sucahyo · Oct 14, 2006

How about problem solving?
Vquick has lift throttle understeer problem on his Holden Monaro. What is your damper tuning suggestion for this?

Week 14 tuning competition entry is closed, so I think giving suggestion this time wouldn't change judging result.

My suggestion would be to increase front bound or reduce rear rebound. Because using softer front would make the front have more grip than rear. My car use higher front damper. Using lower front damper would make the understeer worst at lift throttle.

Scaff · Oct 16, 2006

sucahyo
What problem? GT4 will behave differently if I treat throttle as on/off setting using wheel? If it is, how different if we see how damper react to that?

I have no idea how GT4 would react if you were to use the throttle pedal of a wheel that way, why on earth would you want to? One of the reasons to move to a wheel & pedal combo is to gain better control over the throttle, so I don't see the point in what you are saying and it's certainly not what I am suggesting.

sucahyo
I don't make the load constantly shifting, I judge how the car behave while the load shifting in one direction, at power on, power off, and turning. It's like:
Do power off while turning, observe.
Do power on while turning, observe.
Do counter steer, observe.

sucahyo
For me, proper control yes, better judgement not always. I prefer to tune at spesific condition, more unstable is what I am looking for when tuning, I do not do this when racing.

I drive DIFFERENTLY at the first stage of tuning. I will purposefully make the car unstable, and force the car to work over it's limit. I am not worying about laptime, I am more concern about how the car handle on it's limit or over it's limit. After I satisfy, I will then drive for fast laptime to see what more I can fix.

Well its certainly a bizarre way of tuning and I have to say from driving your set-ups it's not one that I personally believe works.

I would also question how this would relate to then using the throttle and/or brakes during fast laps, as you have already said you flick it on and of to control speed. That would result in load transfer changing before it had finished, totally different from what you are suggesting above.

Simply cornering with either no throttle or full throttle is looking at load transfer in a fixed state, so for full throttle is always thrown to the rear and if this is during a turn then also to the outside of the car.

Compare this with rapidly switching the throttle on and off, which is going to result in the load transfer always being in flux, constantly changing it direction. Now I have already discussed how GT4 'helps' to minimise the effects of this to quite a degree, but it's still not the same as holding the throttle open or closed for the entire corner.

sucahyo
No, not like that. I still believe that visual can be used for tuning camber, still believe that using camber more than roll angle is excessive. It's just that how the car behave when using below or above optimal camber confuse me. Now, if I decide to use camber, I would make sure that camber angle is bellow max roll angle in all corner, or if I tune for drifting, make sure that camber angle always exceed max roll angle in all corner. The car behaviour when roll angle passing camber angle in mid corner make tuning complicated for me.

So are you saying that you do not fully understand it, as you have previously been very dismissive of people who disagreed with you on this subject.

In addition I would also have to say that your claims are not supported by the majority of GT4 tuners and certainly not by the real world as already shown in the thread on this subject.

sucahyo
Uh, what is the name of state when load transfer is happening ? turn in is before that, entry is after that?
And do you have some information about damper role during turn in? during entry, and damper role when load transfer happen?

Uhh the name for load transfer is load transfer, its doesn't matter when it occurs its still called the same thing.

In regard to info on the role dampers play in all situations I have already posted pages and pages of information on this subject.

sucahyo
More like I ignore anything else beside front and rear grip balance.

That's even more concernining than if you were not able to feel or understand it.

Do you think that if you ignore it then it does not count?

Why are you ignoring it, as its vital information to use when tuning.

sucahyo
Still not clear. That do not explain why you feel slugish and poor steering steering during turn-in using lower damper value.

First I did not say that sluggish turn-in was the result of just soft damper settings, so please do not try and make it seem as if I did.

I quite clearly listed the main areas that can effect turn-in, as well as explained when turn-in occurs.

You appear to be under the belief that load transfer occurs instantly, and it certainly does not. If you are braking into a corner in a straight line then load will be towards the front of the car, but fairly evenly split between the front tyres.

The moment you begin to turn into the corner the factors I listed will determine how quickly the tyres actually turn, load only begins to shift once you actually start to turn. The role dampers play in this (which is only part of the picture) is that softer dampers are able to react earlier to the load transfer than stiffer dampers.

This is however simply part of the picture.

sucahyo
I use corner to test my tuning. During testing, I don't care if I end up hitting the wall or thrown to grass. It would be great if there is parking lot or wide flat place in GT4. Or it is exist and I don't know it?

The gymkhana section (in the Driving Park) is just that.

However I fail to see what hitting a wall or running over the grass is going to teach you about tuning, rather it would seem to indicate that your driving needs to improve.

The only way you will be able to clearly see the differences between settings is by running consistent laps, not aiming for ever faster laps, rather lap after lap of fast but consistent times. This allows you to pick up on the small changes that have been made.

sucahyo
I think it's better if we use your way of driving. How the car behaviour change after you put lower front damper on hyundai tiburon at the second hairpin at grand valley when:

"Approaching the corner I will tend to brake hard and early to reduce the speed carried through from the previous section,"

1. I reduce the braking as I begin to turn-in (trail braking. Turn-in is the critical, but short lived period when the front tyre nearest the corner is asked to initiate the cars initial change in direction.

2. As the load begins to shift to the outside of the car I will balance the throttle to maximise the speed I can carry through the corner, using small correction of the throttle and steering to hold the car on the limit of grip.

3. As the corner apex is crossed I gradually and smoothly start to apply the power

4. and unwind the steering lock, as the load transfers to the rear of the car, working to get back on the power as quickly, but smoothly as possible.

If you can, please explain how the car understeer or oversteer.

sucahyo
How about problem solving?
Vquick has lift throttle understeer problem on his Holden Monaro. What is your damper tuning suggestion for this?

Week 14 tuning competition entry is closed, so I think giving suggestion this time wouldn't change judging result.

My suggestion would be to increase front bound or reduce rear rebound. Because using softer front would make the front have more grip than rear. My car use higher front damper. Using lower front damper would make the understeer worst at lift throttle.

The above is going to have to wait as I am away with work for the next few days and would need access to GT4 (and enough time) to give answers.

I do however find it strange that once again you are the one making the claims that something is wrong with GT4, but I am the one doing the testing. Testing that you always seem to refuse to accept the results of. I mean for almost the entire dampers thread you did no tests or write-ups, yet dismissed every one of mine without any a descent explanation or test of your own.

You are also now complaining that my write-ups lack detail, when you own are single lines and often make little sense.

All I can say is that its a good job I enjoy testing, but I have not intention of wasting my time if you are going to simple dismiss every thing I say.

Regards

Scaff

sucahyo · Oct 17, 2006

Scaff
I have no idea how GT4 would react if you were to use the throttle pedal of a wheel that way, why on earth would you want to? One of the reasons to move to a wheel & pedal combo is to gain better control over the throttle, so I don't see the point in what you are saying and it's certainly not what I am suggesting.

When trying to find out how the car affected by damper, I don't think different controller would give different result.

Scaff
Well its certainly a bizarre way of tuning and I have to say from driving your set-ups it's not one that I personally believe works.

There is a huge change in my tuning style between week 4 (BMW M3) and week 9 (Ford GT). My Ford GT tuning is much better than my BMW M3.

Scaff
I would also question how this would relate to then using the throttle and/or brakes during fast laps, as you have already said you flick it on and of to control speed. That would result in load transfer changing before it had finished, totally different from what you are suggesting above.

That's a forced "I have to" driving style. During this stage damper tuning help a lot. This will help handling other style of driving too.

Scaff
Simply cornering with either no throttle or full throttle is looking at load transfer in a fixed state, so for full throttle is always thrown to the rear and if this is during a turn then also to the outside of the car.

I tune stabilizer at this stage, I don't tune damper.

Scaff
Compare this with rapidly switching the throttle on and off, which is going to result in the load transfer always being in flux, constantly changing it direction. Now I have already discussed how GT4 'helps' to minimise the effects of this to quite a degree, but it's still not the same as holding the throttle open or closed for the entire corner.

rapidly switching the throttle on and off is condition 1
holding the throttle open or closed for the entire corner is condition 2

Scaff
In addition I would also have to say that your claims are not supported by the majority of GT4 tuners and certainly not by the real world as already shown in the thread on this subject.

No problem. I use what I know and believe to tune my car, just like everyone else. I am really thankfull for the existence of tuning competition. With this competition I can see how my GT4 tuning compared to someone else.

Scaff
Uhh the name for load transfer is load transfer, its doesn't matter when it occurs its still called the same thing.

I see.

Scaff
In regard to info on the role dampers play in all situations I have already posted pages and pages of information on this subject.

most reference mention about how damper role during road irregularity. Maybe there is some more that explain about hot damper affect cornering.

From this:
"A stiffer bump setting slows down the motion on its corner ans speeds up the load transfer. A softer bump setting does the opposite - it allows the suspension to move faster and spreads the changes in loading out over a longer period of time. The same is true of rebound. Stiff re-bound settings will force the suspension system to move more slowly when loads are removed from its corner of the car, but the unloading of the contact patch will be more abrupt. Softer rebound settings allow the suspension to move more quickly and the unloading of the contact patch happens more gradually"

"The greater the load transferred to the outside, the more the CF of the loaded tires will suffer. Less load transfer means a higher overall CF for all four tires and, consequently, greater traction and cornering speed" (same is true for braking.... but replace slip angle with % slip)."
I conclude that car end with softer damper provide more grip during load transfer.

Scaff
That's even more concernining than if you were not able to feel or understand it.

Do you think that if you ignore it then it does not count?

Why are you ignoring it, as its vital information to use when tuning.

My reference explain mostly how damper make car understeer and oversteer

"SHOCK COMPRESSION:
The stiffer the FRONT shocks, (higher the number) the tighter the car will be when braking.
The softer the FRONT shocks, (lower the number) the looser the car will be when braking.
The stiffer the REAR shocks, (higher the number) the looser the car will be under acceleration.
The softer the REAR shocks, (lower the number) the tighter the car will be under acceleration.
SHOCK REBOUND:
The stiffer the FRONT shocks, (higher the number) the tighter the car will be under acceleration.
The softer the FRONT shocks, (lower the number) the looser the car will be under acceleration.
The stiffer the REAR shocks, (higher the number) the looser the car will be under braking.
The softer the REAR shocks, (lower the number) the tighter the car will be under braking."

Judging from this, I assume tighter is more understeer.
"Front Brake Bias synopsis:
More front brake bias will tighten the chassis entering a corner under braking.
Less front brake bias will loosen the chassis entering a corner under braking."

Scaff
First I did not say that sluggish turn-in was the result of just soft damper settings, so please do not try and make it seem as if I did.

It happen worst after you change damper value.

Scaff
You appear to be under the belief that load transfer occurs instantly, and it certainly does not. If you are braking into a corner in a straight line then load will be towards the front of the car, but fairly evenly split between the front tyres.

The moment you begin to turn into the corner the factors I listed will determine how quickly the tyres actually turn, load only begins to shift once you actually start to turn. The role dampers play in this (which is only part of the picture) is that softer dampers are able to react earlier to the load transfer than stiffer dampers.

What react earlier to the load transfer do to car handling?

Scaff
The gymkhana section (in the Driving Park) is just that.

Thanks.

Scaff
The only way you will be able to clearly see the differences between settings is by running consistent laps, not aiming for ever faster laps, rather lap after lap of fast but consistent times. This allows you to pick up on the small changes that have been made.

By driving like what I do, I can clearly see the difference too.

Scaff
The above is going to have to wait as I am away with work for the next few days and would need access to GT4 (and enough time) to give answers.

I do however find it strange that once again you are the one making the claims that something is wrong with GT4, but I am the one doing the testing. Testing that you always seem to refuse to accept the results of. I mean for almost the entire dampers thread you did no tests or write-ups, yet dismissed every one of mine without any a descent explanation or test of your own.

You are also now complaining that my write-ups lack detail, when you own are single lines and often make little sense.

All I can say is that its a good job I enjoy testing, but I have not intention of wasting my time if you are going to simple dismiss every thing I say.

Ok. I thought that by using your way of driving, you would still remember how your tiburon react to your tuning. I use VQuick problem as Monaro is the car that I already test. I feel Monaro understeer at condition 1 and condition 2. By using lower front damper (softer for me) I reduce the understeer at condition 1. I am really interested on how you solve this.

The way you solve monaro lift throttle understeer is important for me to know how you tune your damper. I am curious wether you will use higher front damper too.

Scaff · Oct 18, 2006

sucahyo
When trying to find out how the car affected by damper, I don't think different controller would give different result.

The controller itself will not change what a values does (any of the tuning values), but a different controller will certainly change how you drive.

A DS2 allows you to apply steering, brakes and throttle far faster than a wheel; the DS2 requires you to move your thumb about 2cm to move from full lock to lock on the thumb stick and depress a button about 5mm to go from no throttle/brakes to full throttle/brakes. Compare that with a DFP and you need to turn the steering wheel either 200 or 900 degree to go from lock to lock and depress a pedal a good 40mm for brakes or throttle.

That makes a huge difference in itself, and that's before looking at how you use these different control methods, you have already said you can't modulate the throttle or brakes and have to 'tap' them on and off, using a thumb stick gives you smoother control than that and a DFP gives you even more (a lot more).

All of these things can make a big difference to how you drive and that effects how you tune, set-ups that can be fine for a DS2 can be poor for a DFP, I use both so I know full well.

Your argument is like saying that changing a steering rack on a car will have no effect on how you drive, which is quite untrue; and if you change how you drive then you may need to change how a car is set-up.

sucahyo
There is a huge change in my tuning style between week 4 (BMW M3) and week 9 (Ford GT). My Ford GT tuning is much better than my BMW M3.

That's a forced "I have to" driving style. During this stage damper tuning help a lot. This will help handling other style of driving too.

sucahyo
No problem. I use what I know and believe to tune my car, just like everyone else. I am really thankfull for the existence of tuning competition. With this competition I can see how my GT4 tuning compared to someone else.

That's good to here, but to be honest you would struggle to put together a set-up as poor (for me) as your first one for the tuning competition. In addition the limited range of the tuning options in GT4 makes it very hard to totally mess up a car in comparison to the real world.

The value ranges in a lot of cases are just far to small, for example just picking up the nearest race parts catalogue next to my desk at home I could buy springs between 50 lbs/in (0.9 kg/mm) to 2,000 lbs/in (35.71 kg/mm), both far in excess of what GT4 will let you use on any car. Its this limitation on range that make total mess-ups hard and values hard to judge.

sucahyo
most reference mention about how damper role during road irregularity. Maybe there is some more that explain about hot damper affect cornering.

From this:
"A stiffer bump setting slows down the motion on its corner ans speeds up the load transfer. A softer bump setting does the opposite - it allows the suspension to move faster and spreads the changes in loading out over a longer period of time. The same is true of rebound. Stiff re-bound settings will force the suspension system to move more slowly when loads are removed from its corner of the car, but the unloading of the contact patch will be more abrupt. Softer rebound settings allow the suspension to move more quickly and the unloading of the contact patch happens more gradually"

"The greater the load transferred to the outside, the more the CF of the loaded tires will suffer. Less load transfer means a higher overall CF for all four tires and, consequently, greater traction and cornering speed" (same is true for braking.... but replace slip angle with % slip)."
I conclude that car end with softer damper provide more grip during load transfer.

My reference explain mostly how damper make car understeer and oversteer

"SHOCK COMPRESSION:
The stiffer the FRONT shocks, (higher the number) the tighter the car will be when braking.
The softer the FRONT shocks, (lower the number) the looser the car will be when braking.
The stiffer the REAR shocks, (higher the number) the looser the car will be under acceleration.
The softer the REAR shocks, (lower the number) the tighter the car will be under acceleration.
SHOCK REBOUND:
The stiffer the FRONT shocks, (higher the number) the tighter the car will be under acceleration.
The softer the FRONT shocks, (lower the number) the looser the car will be under acceleration.
The stiffer the REAR shocks, (higher the number) the looser the car will be under braking.
The softer the REAR shocks, (lower the number) the tighter the car will be under braking."

Judging from this, I assume tighter is more understeer.
"Front Brake Bias synopsis:
More front brake bias will tighten the chassis entering a corner under braking.
Less front brake bias will loosen the chassis entering a corner under braking."

The first part of the above piece is very similar to what is written in the first of my tuning guides, the second piece is also similar. You are right that tighter is normally used to refer to understeer, commonly in Oval racing. Do you have links to those two pieces out of interest.

sucahyo
It happen worst after you change damper value.

No it gets worse when I am using very soft dampers and springs, you are once again just taking a single value and looking at it in isolation. Leaving the damper values low and increasing the spring rate will once again change how the car feels.

You seriously need to get away from treating each setting in isolation, you simply can't do this. Each and every values can and will effect the other, you need to think about how they are all working together at any given point.

Its why you can't tune a car at one ride height, then drop it by, say, 50mm and expect it to be the same. Do that an you may need to work on every value again.

sucahyo
What react earlier to the load transfer do to car handling?

????? Your question makes no sense to me at all????

sucahyo
By driving like what I do, I can clearly see the difference too.

Sorry but for me the only way to see real differences is to drive consistent (but fast) laps, aim for a faster and faster lap time and you will change your line and also adapt and drive around tuning flaws.

sucahyo
Ok. I thought that by using your way of driving, you would still remember how your tiburon react to your tuning. I use VQuick problem as Monaro is the car that I already test. I feel Monaro understeer at condition 1 and condition 2. By using lower front damper (softer for me) I reduce the understeer at condition 1. I am really interested on how you solve this.

The way you solve monaro lift throttle understeer is important for me to know how you tune your damper. I am curious wether you will use higher front damper too.

I never pass comment without referring to either my notes or out of preference having just driven the car.

One thing I did find in my notes about the Monaro (from a set-up I did a long time ago) is that it does not seem to like the full race suspension at all, particularly if the track is bumpy.

I will re-do these tests as soon as I can.

BTW - As you sure you have typed the bit I have highlighted in bold correctly, as you have always said that dampers are softer with higher values. The rest of us quite happily say that lower damper values are softer.

Regards

Scaff

sucahyo · Oct 19, 2006

Scaff
All of these things can make a big difference to how you drive and that effects how you tune, set-ups that can be fine for a DS2 can be poor for a DFP, I use both so I know full well.

Your argument is like saying that changing a steering rack on a car will have no effect on how you drive, which is quite untrue; and if you change how you drive then you may need to change how a car is set-up.

After having poor result at the first 3 of tuning competition, I keep thinking how I can create good setup for both DS2 and sheel using my controller limitation. In order to do that I try to play other racing game which allow tuning.

This is when I found Viper Racing and GPL to be a good reference. In both game I found that using stabilizer has significant effect to cornering handling. So I start using stabilizer. After this I start to think about using damper too. And think about the suspension effect on different load transfer condition.

I satisfied with the result so far. My tuning for tuning competition is not complete yet, there is some more suspension tuning that I still dont have a chance to properly learn during load transfer or not, downforce, camber, ride height, toe, BBC, LSD.

So, I think using whatever controller, you can create good setup with conditioned tuning. Maybe I'll try to see how suspension react when I do spiral in gymkaha. Seeing how suspension tuning has effect at different speed. Maybe after this I can create car that handle good at low speed and high speed.

Scaff
That's good to here, but to be honest you would struggle to put together a set-up as poor (for me) as your first one for the tuning competition. In addition the limited range of the tuning options in GT4 makes it very hard to totally mess up a car in comparison to the real world.

The value ranges in a lot of cases are just far to small, for example just picking up the nearest race parts catalogue next to my desk at home I could buy springs between 50 lbs/in (0.9 kg/mm) to 2,000 lbs/in (35.71 kg/mm), both far in excess of what GT4 will let you use on any car. Its this limitation on range that make total mess-ups hard and values hard to judge.

I admit that my first 3 of tuning competition entry has spoor handling. That was when I try to tune the car mainly by spring rate, ride height and camber. I don't give much attention to stabilizer and damper, I use it to cure something else, not understeer or oversteer handling. Now when I tune mainly with stabilizer and damper, I finally get better result.

Agree that tuning in GT4 is limited.

Scaff
The first part of the above piece is very similar to what is written in the first of my tuning guides, the second piece is also similar. You are right that tighter is normally used to refer to understeer, commonly in Oval racing. Do you have links to those two pieces out of interest.

Ok. http://www.racelinecentral.com/RacingSetupGuide.html or Nascar 2003 Racing Season Garage 101 Guide Download .pdf Document

Scaff
No it gets worse when I am using very soft dampers and springs, you are once again just taking a single value and looking at it in isolation. Leaving the damper values low and increasing the spring rate will once again change how the car feels.

I conclude it because it get worse when you change damper value:
"Spring Rate f3.8 (min) / r5 (default)
Slower initial turn-in , but not too bad, better overall grip from the front-end. Still feels still stiff and slow to react to load transfer.

Spring Rate f3.8 (min) / r5 (default)
Damper fb1/fr1 (min) / rb8/rr8 (default)
Very sluggish turn-in and poor steering response, but excellent front-end grip, particularly in slower corners, but only when the car was 'set' and the load over the front. Overall the front feels soft over curbs in comparison to the last two set-ups."

I assume very sluggish turn-in is worse than slower initial turn-in.

Scaff
????? Your question makes no sense to me at all????

"The moment you begin to turn into the corner the factors I listed will determine how quickly the tyres actually turn, load only begins to shift once you actually start to turn. The role dampers play in this (which is only part of the picture) is that softer dampers are able to react earlier to the load transfer than stiffer dampers."
Damper role during this stage will result in more or less grip to car end with softer damper?

Scaff
Sorry but for me the only way to see real differences is to drive consistent (but fast) laps, aim for a faster and faster lap time and you will change your line and also adapt and drive around tuning flaws.

Ok. I use my method because of my limitation.

Scaff
I never pass comment without referring to either my notes or out of preference having just driven the car.

Ok.

Scaff
One thing I did find in my notes about the Monaro (from a set-up I did a long time ago) is that it does not seem to like the full race suspension at all, particularly if the track is bumpy.

Me too, but since no other part has stabilizer I have to use FC suspension ([rant]why PD? stabilizer usually modded because it's cheap, maybe more people use it than sport suspension package[/rant]) . I use min spring rate for my Monaro.

Scaff
I will re-do these tests as soon as I can.

Thanks.

Scaff
BTW - As you sure you have typed the bit I have highlighted in bold correctly, as you have always said that dampers are softer with higher values. The rest of us quite happily say that lower damper values are softer.

It was a typo, my mistakes. It should be "By using higher front damper (softer for me) I reduce the understeer at condition 1.". I use 10/1 10/1.

sucahyo · Oct 21, 2006

I keep thinking about how I supposed to decide how much damper rebound value needed for some bound value. After playing around trying to reduce corner zigzaging in GPL, I conclude that it is easier to decide it by looking at the car behaviour when on or off throttle.

Softer front bound compare to rear rebound will make the car more oversteer at off power. and softer rear bound compare to front rebound will make the car more understeer at on power.

So, if the current handling is more understeer at off power compare to on power than I should soften bound. This way car will be more oversteer at off power and more understeer at on power.

sucahyo · Oct 30, 2006

Last week I happen to have another chance to play GT4. This time I have to help my relative to win the beginner, roadster convertible race in Infineon. His car is lighly tuned MR2 (maybe spider). His problem is this car is slow on corner.

So, it is my chance to "show off" my skill. It doesn't need a lap to show my horrible handling :lol:

. At least I can keep it on the road, maybe because his controller is better than what I used to. The car feel understeer at push throttle, and oversteer at lift throttle.

I don't have much time, so I don't take this car to freerun mode, I just continue hitting retry again. It's a good thing that he already purchased FC suspension, so I can tune my now favorite part, stabilizer. I use my standard initial setting, then use 1/7 stabilizer hoping this will improve cornering ability, then 1/1 10/10 damper hoping to make on power more oversteer than off power, and lastly midrange ride height.

The car handle better now, it can out corner all the enemy if I can make a good corner entry (they all go so much wider :lol:

). But the oversteer at throttle lift off still a problem, I spin at the second lap just after beating those fast red car (MX5?). So I try to do quick fix, using max front spring rate (rear is min) hoping it will make the front loose grip more during lift off throttle and some other changes (maybe ride height). The result is the opposite, the oversteer during throttle lift off is worse. The car want to spin on almost every corner.

So, I revert all back and apply the first tuning again. I finally can win the race after driving with more carefull control.

The worse oversteer surprise me, I suspect it's the spring rate that caused this. I thought much stiffer spring rate will only do reverse effect at condition 2, not condition 1. But since I am not in "observing mode" during this occasion, I am not so sure about this, I will do more test with MR2 before making conclusion. I am telling this experience to see if you have the same experience.

sucahyo · Nov 8, 2006

Just to inform a really happy moment for me, all tuning competition 14 judge like my condition 1 and condition 2 tuning

.

It turn out that my solution for monaro lift off understeer works fine for the judge. Although for some it will make it a bit oversteer, but in general it still give good handling.

By using max front and min rear bound and rebound damper (10/1 10/1), judge feel that my car lift off throttle behaviour is toward reduced understeer, I think this should be an good sign of improvement since during tuning me and other tuner feel the car has bad understeer, Vquick even complain about this car lift off understeer particularly. I am sure that if I use the reverse value (1/10 1/10), all judge will critisize lift off throttle understeer.

Thank you Duċk for moderating tuning competition

. Tuning competition really improve my tuning, from very poor result to now satisfying result

👍. There are still a lot more to learn so I wish tuning competition will always active.

My conclusion after 4th entry in tuning competition since I tune damper for load transfer only:
- 10 at front will have more grip during load transfer than 1 at the rear.
- during load transfer, car end which have higher damper value will have more grip than when it has equal value

Scaff, I hope you have time to test your damper solution for monaro lift off throttle understeer and maybe for ford gt concept lift off throttle oversteer. I'll be waiting your solution patiently

. In the mean time I will keep inform my progress on exploring GT4 and GPL (maybe Viper Racing too) physics here.