Getting rid of understeer during braking (Skyline R34)

[Scaff]

IMO, stiffer front spring will make the understeer problem worse. If we set front spring stiffer, the load transfer on front end will happen faster (relative to the rear). Faster load transfer will result in faster front tire overload. This happen only when the load transfer still in progress.

Unless you are looking at massively stiff spring rates (and I'm talking about far stiffer than GT4 will allow you to set) then spring rate has little effect on the speed of the load transfer. I always recommend keeping the following in mind "Springs determine how much the car will move, dampers will determine how quickly it does it", yes some interplay between these two does occur, but the fundamental statement is correct.

If the braking is long enough and load transfer no longer happen, the end which has more weight distribution will have more traction.

Sorry but that is not always true at all, heavy load transfer in any one direction can have many, many outcomes and not all of them leave the end with the most load with the most grip at all.

In fact in racing we want to minimise the overall level of load transfer as much as possible, to keep is spread as evenly as we can across the four tyres. In an ideal world we want the four contact patches to be doing as much work as they each can. That's why race cars are build to keep the cog as near to the centre of the car and as low as possible, as it minimises load transfer (and its helpful in regard to the cars Polar Moment of Inertia).

The graphs I posted earlier clearly show that as load increases so does grip, but only up to a point, after that 'limit' is reached any further increase in load will reduce grip. If load transfer takes a tyre/end of a car above this limit then regardless of if the transfer is happening or has finished its still going to have reduced grip.

But regaining back front traction that already lost can take a while. Moreover, if the damper is not too restricting, the car will never reach stable condition, and front end will always bounce up and down.

That would require a damper setting that is very soft, and in all likelihood un-damped spring oscillation would be a factor long before traction was lost. I would however agree that regaining front traction can be very difficult (depending on how far into understeer the car has gone), more difficult than some people believe.

As load transfer happen, car end which has stiffer suspension will have relatively less grip.

As a basic rule I would agree.

But then again if the weight doesn't transfer away from the rear wheels, they will have so much grip that IT makes the car understeer as well. damn if you do and damn if you don't. Extreme example could be a heavy-ish MR/RR car on wet track. Front wheels planing on the water whereas the rears have so much grip that power-over is out of options.

Thus one has to find a balance between these two.

👍 Could not agree more, which is why I have always maintained that extreme settings are very problematic and unless testing is carried out in a 'step-by-step' manner the results can be very confusing.


Regards

Scaff

 

[sukerkin]

I feel so envious of 'todays' members with such expert help on tap, so to speak - I had to teach myself all this and then try to pass it on (back in the days when I was considered a Tuning Guru around here ).

So "Huzzar!" for Scaff, Greycap, Leonidae et al for being such a resource 👍.

The biggest trend that seems to occur when people begin to complain of understeer is that they tighten and stiffen everything up. As has been pointed out already, if all that rigidity passes load to the tyre that was losing traction in the first place then things just get worse .

It's always going to be a battle of compromises when you're dialing in a car and it only gets worse when you start trying to get 200 A-Spec performance and tyre endurance out of the same chassis - that tho' is an area in which I've found the most fun and challenge in the game. No wings, loads of ballast, glass-hard tyres ... you soon find out how 'magic' or otherwise your spanners are .

 

[Leonidae]

This problem is actually quite common with GT-R's, especially R34's that have uneven weight distribution of 57% front and 43% rear. The older models have bit better weight distribution, thus I prefer R32..

 

[sucahyo]

Unless you are looking at massively stiff spring rates (and I'm talking about far stiffer than GT4 will allow you to set) then spring rate has little effect on the speed of the load transfer.

Well, I said that because when I experimenting how car handling changed by spring rate in GT4, I found that at moment I press the brake while turning, stiffer (+2) front spring rate will reduce the front tire traction, less traction than before. I do this experiment on Holden Monaro, at soft FC supension setting, I forget the track, maybe Tokyo 249.

Sorry but that is not always true at all, heavy load transfer in any one direction can have many, many outcomes and not all of them leave the end with the most load with the most grip at all.

Ok.

The graphs I posted earlier clearly show that as load increases so does grip, but only up to a point, after that 'limit' is reached any further increase in load will reduce grip. If load transfer takes a tyre/end of a car above this limit then regardless of if the transfer is happening or has finished its still going to have reduced grip.

Actually, that graph is just like what I am looking for Scaff. I currently trying to tweak Viper Racing and Nascar Heat tire, which I think still can be improved. Both game created by the same developer. But even when both game use the same tire data, the tire behaviour is very different. I found that a change on single variable in tire data can give very different handling. This make me learn Pacejka magic Formula:


and learn how to change it from some literature:


Your graph make me learn something new. So thanks for posting it .

 

[Parnelli Bone]

I wish i had more time to read this full discussion. I gotta go to bed soon and get up early but it looks interesting.

 

[Scaff]

Well, I said that because when I experimenting how car handling changed by spring rate in GT4, I found that at moment I press the brake while turning, stiffer (+2) front spring rate will reduce the front tire traction, less traction than before. I do this experiment on Holden Monaro, at soft FC supension setting, I forget the track, maybe Tokyo 249.

That may well be the case, but it does not mean that its due to a change in the speed of load transfer. Rather its due to a stiffer front spring rate changing how the load is distributed between the two front wheels. As I mentioned earlier, take a look at the section on spring stiffness in either my first tuning guide or Greyout's thread, both explain this fully.

Your graph make me learn something new. So thanks for posting it .

No problem at all, glad it was handy.


Regards

Scaff

 

[sucahyo]

That may well be the case, but it does not mean that its due to a change in the speed of load transfer. Rather its due to a stiffer front spring rate changing how the load is distributed between the two front wheels.

From your opinion, how do we know the difference?

 

[Scaff]

From your opinion, how do we know the difference?

Uhh not my opinion, rather the laws of physics.

If (and it is of course an if) GT is following the basic laws of physics then a change in spring rate itself (and certainly give the narrow range offered by GT4) will have little to no effect on the speed of load transfer (as that's mainly a factor if resistance in the system and the vast majority of that comes from the dampers). So if the damper rates are not being changed but the spring rates are then speed of load transfer is not being affected, but the distribution of load between the two front tyres is. Stiffening the spring rates gives the system less ability to evenly spread this load (see my guide or Greyout's stuff for the exact reason why) and the result is understeer.


Regards

Scaff

 

[sucahyo]

I see.

I mention load transfer because of this:
Holden Monaro test, after using stiffer front spring rate:
load-transfer-handling: increased understeer
no-load-transfer-handling: not increased understeer


To help a Trico Pro understand why stiffening front spring rate add understeer, I give some more example since it seems grayout's guide mention acceleration only.

I will use Colcob's LFS GT suspension analyserV2-2.xls. Let's believe what Colcob said about Scawen (LFS main programmer) help him correct this excel file physics. For this experiment I change the car weight distribution to 50:50.

At no lateral and no longitudinal force, standing still, spring rate at 21.2/21.2 (F/R) the spring loads is:
	left	right
front	2882.6	2882.6
rear	2882.6	2882.6

[b]cruising[/b]
At -0.75g lateral and no longitudinal force, left turn cruising, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	1230.0	4535.3
rear	1230.0	4535.3

At -0.75g lateral and no longitudinal force, left turn cruising, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	916.5	4848.8
rear	1435.6	4329.7


[b]braking[/b]
At -0.75g lateral and -0.75 longitudinal force, left turn braking, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	2247.3	5552.6
rear	212.6	3517.9

At -0.75g lateral and -0.75 longitudinal force, left turn braking, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	1967.0	5899.3
rear	385.0	3279.2


[b]acceleration[/b]
At -0.75g lateral and 0.25 longitudinal force, left turn acceleration, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	890.9	4196.2
rear	1569.1	4874.4

At -0.75g lateral and 0.25 longitudinal force, left turn acceleration, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	566.3	4498.6
rear	1785.7	4679.9

In all experiment, increasing front spring rate increase front outside suspension load. Don't know if this load exceed tire optimum traction or not. Exceeding = more understeer.

If we assume that tire optimum traction is at 5000, then:
- at cruising stiffer front = more oversteer.
- at braking stiffer front = more understeer.
- at acceleration, stiffer front = more oversteer.

Remember that this experiment assume that the lateral and longitudinal force are static, while in reality it can be dynamic too. Things can be different when weight shifting happen.


Consider a front heavy FR car. What I think happen when this car equipped with stiffer spring rate:
case 1: heavy braking. More understeer. Even if the shifted weight reduced and the front tire still at it's optimum traction according to weight distribution calculation, the tire will still be overload because during load transfer front tire will receive faster weight shifting. And faster weight shifting means more force at the same time will be feed to the front tire.

case 2: mild acceleration. More understeer. Even if the tire still bellow it optimum traction, it can be more understeer as there are still more sudden weight shifting at front, trying to lift the front tire, reducing more of it's traction.


Scaff, I assume spring rate has role in load transfer base from literature University of Texas, Physics review & bond graphs: Mechanical Translational

Resistance not only come from damper but also from spring. Maybe you mean to say that spring range is too limited in GT4 compare to it's damper. But I think it's the other way around, I think damper range is too limited in a way that we can only notice significant difference on car behaviour when changing spring, not so noticable when changing damper.


BTW, Scaff, do I see correctly that your car in this picture is turning left?

 

[Parnelli Bone]

...interesting stuff..

 

[Scaff]

I see.

I mention load transfer because of this:
Holden Monaro test, after using stiffer front spring rate:
load-transfer-handling: increased understeer
no-load-transfer-handling: not increased understeer

How exactly are you measuring understeer here and how are you ensuring that the conditions are exactly repeated for each run through?

Is the tyre grip being exceeded every single time and by how much, sorry to sound a bit negative but its a bit hard to form any definite opinion from just the above.

To help a Trico Pro understand why stiffening front spring rate add understeer, I give some more example since it seems grayout's guide mention acceleration only.

I will use Colcob's LFS GT suspension analyserV2-2.xls. Let's believe what Colcob said about Scawen (LFS main programmer) help him correct this excel file physics. For this experiment I change the car weight distribution to 50:50.

At no lateral and no longitudinal force, standing still, spring rate at 21.2/21.2 (F/R) the spring loads is:
	left	right
front	2882.6	2882.6
rear	2882.6	2882.6

[b]cruising[/b]
At -0.75g lateral and no longitudinal force, left turn cruising, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	1230.0	4535.3
rear	1230.0	4535.3

At -0.75g lateral and no longitudinal force, left turn cruising, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	916.5	4848.8
rear	1435.6	4329.7


[b]braking[/b]
At -0.75g lateral and -0.75 longitudinal force, left turn braking, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	2247.3	5552.6
rear	212.6	3517.9

At -0.75g lateral and -0.75 longitudinal force, left turn braking, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	1967.0	5899.3
rear	385.0	3279.2


[b]acceleration[/b]
At -0.75g lateral and 0.25 longitudinal force, left turn acceleration, spring rate still at 21.2/21.2 the spring loads is:
	left	right
front	890.9	4196.2
rear	1569.1	4874.4

At -0.75g lateral and 0.25 longitudinal force, left turn acceleration, spring rate change to 28.8/21.2 the spring loads is:
	left	right
front	566.3	4498.6
rear	1785.7	4679.9

Good interesting stuff

In all experiment, increasing front spring rate increase front outside suspension load. Don't know if this load exceed tire optimum traction or not. Exceeding = more understeer.

Yes if a single front tyre tyre is exceeding grip then we can say the car will have an understeer balance, however that is a very simplistic look at what is happening. True car balance comes not just by looking at which end looses grip first, but from looking at the actual Slip Angles (and if required the slip pecentages as well) for each tyre and then seeing how they compare to each other. I cover this in my first guide...

...so in a situation when grip has not been exceeded on a single (or more) tyre, then we need to look at a bit more info. Dynamic balance once grip has been exceeded is easy to judge, under the limit its far harder to predict.

If we assume that tire optimum traction is at 5000, then:
- at cruising stiffer front = more oversteer.
- at braking stiffer front = more understeer.
- at acceleration, stiffer front = more oversteer.

As I pointed out above its unfortunately not quite that simple in all cases, you see in all the cases you claim oversteer, if you actually look at the difference between the grip on each corner the front always has the biggest difference, so the front tyres are the ones with the poorer spread of grip and the ones most likely to be closer to the slip limits. Sorry but these all indicate understeer.

cruising
At -0.75g lateral and no longitudinal force, left turn cruising, spring rate change to 28.8/21.2 the spring loads is:
left right
front 916.5 4848.8 = 3932.3 difference
rear 1435.6 4329.7 = 2894.1 difference
The load is less evenly spread between the front tyres and the result will be understeer


braking
At -0.75g lateral and -0.75 longitudinal force, left turn braking, spring rate change to 28.8/21.2 the spring loads is:
left right
front 1967.0 5899.3 = 3932.3 difference
rear 385.0 3279.2 = 2894.2 difference
The load is less evenly spread between the front tyres and the result will be understeer, however as the front right has exceeded it limit we would be looking at quite extreme understeer.


acceleration
At -0.75g lateral and 0.25 longitudinal force, left turn acceleration, spring rate change to 28.8/21.2 the spring loads is:
left right
front 566.3 4498.6 = 3932.3 difference
rear 1785.7 4679.9 = 2894.2 difference
The load is less evenly spread between the front tyres and the result will be understeer, keep in mind that the front inside tyre (left) has almost no load on it at all, the resulting CF value would be extremely low and little grip would be being generated, a situation as bad as overloading a tyre.

Now if we take this last one a bit further and use the following graph (from a previous post of mine) as an example of CF generated by load...

..now I am going to divide your load value all by 10 to get some reading we can plot on the graph, and what we get (approx) is

Front
Left - 56.6 = CF 0.1
Right - 449.8 = CF 1.1

Rear
Left - 178.5 = CF 0.6
Right - 467.9 = CF 1.2

Now as all the tyres are below the limit we can clearly see the front left is the weak point here and no matter how much grip the front right is generating, as the left it not helping out its the front end of the car with the biggest problem. Looking at it very simply the front has a combined CF of 1.2 and the rear 1.8, clearly the front has less grip than the rear (despite the fact that neither end has actually lost grip).

we can even take this one step further and look at effective traction at each corner, think back to basic physics that frictional force = CF x vertical load we can calculate the following.

Front
Left - CF 0.1 * 56.6 = 5.66
Right - CF 1.1 * 449.8 = 494.78

Rear
Left - CF 0.6 * 178.5 = 107.1
Right - CF 1.2 * 467.9 = 561.48

Here we can see that front left tyre is the critical point, offering little in the way of real grip. Combine this with the previous factors and it doesn't look good at the front end.

You see what is critical is the manner in which the load is spread and how that will relate to slip angles, the more one tyre is asked to do at the expense of another (or the biggest difference in how load is shared at a given end) determines the balance, particularly if one or more tyre has not yet reached its limit.

Keep in mind that both tyres at a given end need to be doing as equal a share of the work as possible to provide a good level of grip, and in this case the stiffened front is not allowing that.

The one exception that could develop from this would be the acceleration one, if you were able to apply sufficient power to a rear tyre(s) to get it/them to exceed the grip limit through acceleration alone (assuming rear wheel drive) then the result would be oversteer (of the power variety). This is one of the ways in which you can get a situation of understeer developing to oversteer as you power out of a corner.

BTW - the fact that the same differences can be seen in all cases would indicate that this is a fairly basic formula in application here, with very few 'realistic' variables in place.

Remember that this experiment assume that the lateral and longitudinal force are static, while in reality it can be dynamic too. Things can be different when weight shifting happen.

I don't disagree with that, but you have confused exactly how the spread of load at a given end works.

Consider a front heavy FR car. What I think happen when this car equipped with stiffer spring rate:
case 1: heavy braking. More understeer. Even if the shifted weight reduced and the front tire still at it's optimum traction according to weight distribution calculation, the tire will still be overload because during load transfer front tire will receive faster weight shifting. And faster weight shifting means more force at the same time will be feed to the front tire.

case 2: mild acceleration. More understeer. Even if the tire still bellow it optimum traction, it can be more understeer as there are still more sudden weight shifting at front, trying to lift the front tire, reducing more of it's traction.

For the reasons I outlined above this is still simply about how the load is spread not because of the speed of transfer. You are mixing up how the spring rates effect balance with how dampers effect balance.

Scaff, I assume spring rate has role in load transfer base from literature University of Texas, Physics review & bond graphs: Mechanical Translational

Resistance not only come from damper but also from spring. Maybe you mean to say that spring range is too limited in GT4 compare to it's damper. But I think it's the other way around, I think damper range is too limited in a way that we can only notice significant difference on car behaviour when changing spring, not so noticable when changing damper.

That link does not constitute literature, rather a series of formula, however I have not at any point denied that spring can have a dampening effect....

Unless you are looking at massively stiff spring rates (and I'm talking about far stiffer than GT4 will allow you to set) then spring rate has little effect on the speed of the load transfer. I always recommend keeping the following in mind "Springs determine how much the car will move, dampers will determine how quickly it does it", yes some interplay between these two does occur, but the fundamental statement is correct.

...however the damping effect from a coil spring is minor in comparison to that of the damper, one of the principal roles of a damper is to put resistance into the system. It would not be effective at this if the spring had a major role to play here. In fact if that was true then why would we need dampers at all (you are arguing here that spring rate changes have a effect on load transfer speeds to overide that of the dampers).

I also totally disagree that changes to damper rates has an insignificant role in speed of load transfer, the tests I carried out on this very subject with the Caterham clearly show that damper rates in GT4 have a significant effect on the speed of load transfer, illustrated by the visible difference in suspension system reaction and the totally different feel.

https://www.gtplanet.net/forum/showpost.php?p=2515759&postcount=272

BTW, Scaff, do I see correctly that your car in this picture is turning left?

The car is facing the 'wrong' way for the turn, I forgot to flip the image for the manual and have not found the time to correct it.


Regards

Scaff

 

[Stunt Drifter]

Jesus scaff how long did that take you? Very detailed and should answer a lot of questions/comments though

 

[Scaff]

Jesus scaff how long did that take you? Very detailed and should answer a lot of questions/comments though

About 20 minutes in all, just glad its of interest.

👍

Scaff

 

[Tulok]

reviewing that was pretty helpful! Thanks Scaff!
just wondering,
for a medium powered FR car, would it be best to use the spring rates to make tire load 50% & 50%?
or to make load more/less to the front/rear tires?
like this:
1200kgs
weight distibution f/r
54% 46%
(just say we need fairly stiff suspension for this application)
13.8 kg/mm 11.75 kg/mm
divide 13.8 by 54, to get 1%,
then multiply by 46 to get the 46%(rear spring rate)
thanks, Tulok(!)

 

[sucahyo]

How exactly are you measuring understeer here and how are you ensuring that the conditions are exactly repeated for each run through?

A repeated attempt on the same corner, verify by a repeated change on front spring rate setting. I don't attempt to get fast laptime during this test. I use the same driving style on all attempt. After this test I also see the same trend on other car too.

The test done while observing sudden braking and sudden hard acceleration behaviour on corner, on how fast the tire start to slide. I do this way to avoid spring anomalies (more grip while corner cruising using stiffer spring rate).

I don't disagree with that, but you have confused exactly how the spread of load at a given end works.

Yes, thanks for the detailed explanation 👍.

That link does not constitute literature, rather a series of formula, however I have not at any point denied that spring can have a dampening effect....

...however the damping effect from a coil spring is minor in comparison to that of the damper, one of the principal roles of a damper is to put resistance into the system.

No, you got it wrong. The spring role in that equation is not because it has dampening power, but because it has elastic power. And you are wrong to say "damping effect from a coil spring is minor in comparison to that of the damper". Because if we look into that equation spring dan damper has an equal share. We do not see a constanta that indicate damper is insignificant or spring is insignificant, both treated as the same. The difference is spring has elastic power, so after it forced to go to one direction, it will try to go back.

In fact if that was true then why would we need dampers at all (you are arguing here that spring rate changes have a effect on load transfer speeds to overide that of the dampers).
...
I also totally disagree that changes to damper rates has an insignificant role in speed of load transfer

I don't say damper has insignificant role. I am saying that spring has much more force range than damper in GT4, make spring rate change more noticeable.


My estimation about GT2 spring strength, hopefully relevant in GT4 too.

Estimation based from "The Stiffness of the Springs - the Suspension Frequency" of Smithees Race Car Technologies (I forget the link, sorry).
car with weight ~2000lb.
spring rate value 2 has spring natural frequency ~60 = ~50lb/in
spring rate value 20 has spring natural frequency ~120 = ~200lb/in

Visible fact in GT2 and GT4:
- damper do it's job at lowest spring value, it can prevent car from bouncing.
- damper do not do it's job at highest spring value, it can not prevent car from bouncing.

I hope it's clear that you can feel this bouncing too during driving, it not just looks.

Visible fact in LFS (LFS S2 Alpha W):
car bounce using damper (damping) at it's highest (14 kNs/m) and spring rate (stiffness) at it's highest (140 kNs/m) has less bounce than car bounce using damper (damping) at it's lowest (1.4 kNs/m) and spring rate (stiffness) at it's lowest (14 kNs/m). But we can easily make the car less bouncy by increasing damper a little. damper can "keep up" with spring stiffness in LFS.


So, Even when in GT4 we can set the spring rate from cardillac like softness to sports car like stiffness, the damper do not has enough setting range to stop the car from bouncing at highest spring rate. Damper range in GT4 is too limited. And I think spring rate range is large enough.

BTW, what make you assume that GT4 spring rate range is too narrow? Using test?

 

[sukerkin]

Have you changed your controller set-up since last we spoke on such issues, Sucahyo? I recall that before you were using a keyboard and running the game via emulator on your PC and so were getting all kinds of erroneous results.

I ask because the conclusions you are drawing are the reverse of my own and it is clear we are drawing on the same real world information sources (it would be nice to be credited occaisionally for the sources, like Smithees, that I (like to think I) brought to the fora in years gone by but c'est la vie).

I find that damper tuning is the most effective tool in the box for dealing with handling matters as they allow me to control the speed with which the suspension will take (and restore from) an attitude into or out of a corner. The spring rates, once you get them into the ballpark area of being strong enough for the weight of the car, make very little impact on handling by comparison, other than via their effect on roll resistance (and the stabalisers are better for dealing with that anyway).

 

[Scaff]

A repeated attempt on the same corner, verify by a repeated change on front spring rate setting. I don't attempt to get fast laptime during this test. I use the same driving style on all attempt. After this test I also see the same trend on other car too.

The test done while observing sudden braking and sudden hard acceleration behaviour on corner, on how fast the tire start to slide. I do this way to avoid spring anomalies (more grip while corner cruising using stiffer spring rate).

As Suderkin has asked, what controler are you using for this, because the result you are getting differ massively from those other seem to get, and in addition what are the full settings for the car, so other can give it a go.

No, you got it wrong. The spring role in that equation is not because it has dampening power, but because it has elastic power.

I don't thinks so to the first part, and I am well aware that a spring does not have a significant damping force, but you are wrong to state it has none. While coil springs have little damping force, leaf spring set-ups can actually have a good degree of damping force (from the friction generated between the blades).

And you are wrong to say "damping effect from a coil spring is minor in comparison to that of the damper". Because if we look into that equation spring dan damper has an equal share. We do not see a constanta that indicate damper is insignificant or spring is insignificant, both treated as the same. The difference is spring has elastic power, so after it forced to go to one direction, it will try to go back.

Without values you are rather bold to state catagorically that the result of that formula will give the springs a damping force equal to that of a damper; you are also blatantly contradicting yourself here, as in the quote above this one you clearly state that spring don't have damping forces.

I also did not say insignificant, I said minor in comparison to.

You are making a few assumptions here, the main one being that a changing in a coil springs rate (or resistance) will effect the speed at which it moves in a significant manner. Or more specifically that it will effect the speed of compression or expansion more that that of the damper fitted to the system. If the suspension system is even close to correctly set-up then the damper will control the spring oscillation, in GT4 we can't even get uncontrolled spring oscillation to any degree. Simply put your theory here is just that, a theoretic possibility, and something no one would ever fit to a car (road or track).

Let me ask you this, under what circumstances would anyone fit dampers so weak to a car that the spring because the principal factor is how quickly the load was transferred? I ask this because while it is theoretically possible, it would mean that the dampers would have to be so soft as to offer no control at all over the springs.

sucahyo, great danger existing in simply looking at formula or data without actually understanding what the real world applications of them is, you have already proven that once in this thread already.

Finally lets have a look at what Skip Barber has to say on the subjects of springs and dampers.

Springs
With soft springs on the front of the car, transferring 200 lbs. to the front under braking might lower the front nose, let's say, 2 inches. Installing stiffer springs in front may limit the change in ride height to 1 inch. The load is the same, it's just the reaction to the load that changes - the front moves down less. If you wanted to keep the front from dipping as all you could weld the front suspension solid and there would be no ride height change in response to the 200 lbs. load. The load still gets to there no matter what you do. The springs determine how much the suspension move in response to the load.

Shocks - Speed of Load Transfer and Motion
With a shock absorber in the system, if there is very little resiatnce to compression the load gets to the tyre relatively slowly, more like it did without a shock in the system. If the shock has a lot of resistance to compression, the load gets to the tyre quicker, essentially bypassing the spring and going directly through the shock. Ultimately, the shock setting doesn't determine how much load gets to the tyre or how much the suspension moves in response to the load. It alters the speed with which the load gets to the contact patch and the speed in which the suspension moves in response to the loads feed into it. (emphasis all the authors)

Now do you not think that if spring rate had an effect on speed of load transfer to the degree you are suggesting in a automotive suspension system that Skip Barber would actually note it?

Well it would seem to me that he in fact directly contradicts you and backs up what I have previously said, springs determine how much the suspension moves, dampers determine how quickly it moves.

I don't however expect you to take a lot of notice of this, given your past track record on twisting and contradicting Skip Barbers work, I just wish you would simply admit that you are wrong on this point, rather than starting another of these topics in which I have to spend the best part of a year simply correcting mistaken opinions presented as fact.

I don't say damper has insignificant role. I am saying that spring has much more force range than damper in GT4, make spring rate change more noticeable.

So you are claiming that spring rates in GT4 are so much stronger than the available damper range that they are the dominant factor in speed of load transfer?

If that's the case then why are the spring rate not constantly overpowering the dampers and everytime we pull away in a car doe sit not start oscillating on its springs, which would be the case if what you claim were true.

My estimation about GT2 spring strength, hopefully relevant in GT4 too.

Estimation based from "The Stiffness of the Springs - the Suspension Frequency" of Smithees Race Car Technologies (I forget the link, sorry).
car with weight ~2000lb.
spring rate value 2 has spring natural frequency ~60 = ~50lb/in
spring rate value 20 has spring natural frequency ~120 = ~200lb/in

Visible fact in GT2 and GT4:
- damper do it's job at lowest spring value, it can prevent car from bouncing.
- damper do not do it's job at highest spring value, it can not prevent car from bouncing.

I hope it's clear that you can feel this bouncing too during driving, it not just looks.

Visible fact in LFS (LFS S2 Alpha W):
car bounce using damper (damping) at it's highest (14 kNs/m) and spring rate (stiffness) at it's highest (140 kNs/m) has less bounce than car bounce using damper (damping) at it's lowest (1.4 kNs/m) and spring rate (stiffness) at it's lowest (14 kNs/m). But we can easily make the car less bouncy by increasing damper a little. damper can "keep up" with spring stiffness in LFS.


So, Even when in GT4 we can set the spring rate from cardillac like softness to sports car like stiffness, the damper do not has enough setting range to stop the car from bouncing at highest spring rate. Damper range in GT4 is too limited. And I think spring rate range is large enough

I can provide a link to it....

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

... and I can also quote the part you conveniently forget to tell people about this bounce test.

Remove the shocks from the car, and disconnect the anti-roll bar(s) if fitted.

and

If the car has coil overs or Mcpherson strut suspension, the "bounce test" cannot be done.

..the reason being that dampers (which you can't remove if you have a coil over or McP strut) will seriously compramise the results, to the point of making them inaccurate.

We can't remove the dampers or anti-rollbars (stabiliers) from GT4, making orthis test totally void (same to a lesser degree with L4S), a fact you seem intent on ignoring and/or dismissing over and over again. Despite the fact that the source you use (and thanks to sukerkin for them) states it make the test void.

Not to mention that I would assume you are basing your theory that GT4 damper rates are not 'resistant' enough at maximum damper rates with your assumption that damper rates are reversed. A theory that I (and just about everyone else) reject, and if incorrect would explain your 'results' and more flawed assumptions.

Come on this is silly, your own source discredits what you are trying to use, and your own tests throw up so many anomalies that force you to come up with bizarre theories that have not link to real world tuning or physics. Simply accepting that you are wrong about damper value sbeing reversed and everything else falls into place, yet you still refuse to even entertain this.

BTW, what make you assume that GT4 spring rate range is too narrow? Using test?

Something rather more simple, the fact that you can buy racing springs with far, far higher rates that GT4 allows you to use. I can pick up a catalogue of motorsport equipment I have in my office and find off the shelf springs with rates as high as 50 kg/mm (Eibach in this example).

I don't need tests to know that GT4's spring rate range is cut off short, simply an actual knowledge of motorsport.


Regards

Scaff

 

[Parnelli Bone]

Good lord you guys are technical! I tried to read all that but now my ibuprofin bottle is calling me.

 

[sucahyo]

Have you changed your controller set-up since last we spoke on such issues, Sucahyo? I recall that before you were using a keyboard and running the game via emulator on your PC and so were getting all kinds of erroneous results.

I use PS2 to play GT4. I use PC to play GT2 and to make (not play) GT4 hybrid. The emulator play other game without change in gameplay, the error should originated from the game.

I ask because the conclusions you are drawing are the reverse of my own and it is clear we are drawing on the same real world information sources (it would be nice to be credited occaisionally for the sources, like Smithees, that I (like to think I) brought to the fora in years gone by but c'est la vie).

Yes, thanks for that. Sorry, I forget that I get that link from you.

I find that damper tuning is the most effective tool in the box for dealing with handling matters as they allow me to control the speed with which the suspension will take (and restore from) an attitude into or out of a corner. The spring rates, once you get them into the ballpark area of being strong enough for the weight of the car, make very little impact on handling by comparison, other than via their effect on roll resistance (and the stabalisers are better for dealing with that anyway).

Once again I must say that I didn't say damper is insignificant, I said damper range is too small. I still use damper to control "during-load-transfer" handling too.

IMO the proper damper range for GT2 or GT4 should be 1 to 25. If you never drive car with damper set at 20 in GT4, I am willing to make you a gamesave for it. NTSC or PAL please mention. But since a change of suspension setting in car setup will revert this value to normal range, you can only trust my word or give the gamesave to other GT4 hybrider to check (or if you can learn to run GT4 in a PC to check it yourself).

As Suderkin has asked, what controler are you using for this, because the result you are getting differ massively from those other seem to get, and in addition what are the full settings for the car, so other can give it a go.

Same as before. The important part is I differentiate the handling between corner cruising (mild acceleration) and corner hard acceleration/braking. If you don't make this differentiation, I doubt you notice it.

I don't thinks so to the first part, and I am well aware that a spring does not have a significant damping force, but you are wrong to state it has none. While coil springs have little damping force, leaf spring set-ups can actually have a good degree of damping force (from the friction generated between the blades).

ok. But it seems there is missunderstanding, I mean spring rate is in the equation primarily because of it's elastic power.

Without values you are rather bold to state catagorically that the result of that formula will give the springs a damping force equal to that of a damper; you are also blatantly contradicting yourself here, as in the quote above this one you clearly state that spring don't have damping forces.

It is not about damper damping force vs spring rate damping force. It is about damper damping force vs spring rate elastic force. I am rather surprise that you never seen an equation like this.

That formula is an equilibrium in one degree of freedom suspension modelling. In this modelling, what is calculated is the damper damping energy, spring elastic energy, energy from road/wheel, energy stored in body.

I also did not say insignificant, I said minor in comparison to.

Agree that spring damping is minor to damper damping, but spring elastic is not.

springs determine how much the suspension moves, dampers determine how quickly it moves.

Agree. But this is how I see it:
damper is same, energy is same, spring is the only one changed:

soft spring make the suspension moves 2 inch.
stiff spring make the suspension moves 1 inch.

wiki:


more force received by stiff spring. More force transfered to tires.

I don't however expect you to take a lot of notice of this, given your past track record on twisting and contradicting Skip Barbers work, I just wish you would simply admit that you are wrong on this point, rather than starting another of these topics in which I have to spend the best part of a year simply correcting mistaken opinions presented as fact.

Ok, I won't argue too long.

So you are claiming that spring rates in GT4 are so much stronger than the available damper range that they are the dominant factor in speed of load transfer?

Correction:
spring rates in GT4 has so much wider range than the available damper range that they are the most noticeable factor in change of speed of load transfer.

If that's the case then why are the spring rate not constantly overpowering the dampers and everytime we pull away in a car doe sit not start oscillating on its springs, which would be the case if what you claim were true.

I already mention that at low spring value, damper do it's job.

We can't remove the dampers or anti-rollbars (stabiliers) from GT4, making orthis test totally void (same to a lesser degree with L4S), a fact you seem intent on ignoring and/or dismissing over and over again. Despite the fact that the source you use (and thanks to sukerkin for them) states it make the test void.

We can now. I can make a gamesave that contain car that will eternally bouncing. We don't need to calculate suspension frequency for LFS, Colcob's LFS_Setup_Analyser already have it.

If we can remove damper and stabilizer, would this make the test not void anymore or are there still other thing to consider to make this test totally void?

If I am not mistaken, this gamesave should has a abnormally bouncy MX5:
850hp MX5 1800RS

This has another kind of bounce, baloon like bounce.
13kg '62 skyline, video showing bouncy behaviour (by PlayGuy).


If I don't mess up my data, this GT4 PAL ARMAX code should change front and rear damper value to 33:
WZV6-M0Q5-FE0FB
P1XQ-2F1E-7BKKK
W4BF-PGXX-KHDUA

If this code do not work, I can fix it. If you don't have ARMAX or you have NTSC version, I can make a gamesave of car with abnormal suspension. With this limit:

Spring rate: 0 to 255
Ride height: -32768 to 32767
Bound: 0 to 255
Rebound: 0 to 255
Camber: 0 to 25.5
Toe: -128 to +127
Stabilizers: 0 to 255


I never get a chance to do proper suspension test with hybrid. But I don't doubt that it will be the same as GT2. So, I see no point of doing it.

On GT2:
0 spring rate still has spring stiffness.
255 damper has the lowest suspension movement restriction.

Something rather more simple, the fact that you can buy racing springs with far, far higher rates that GT4 allows you to use. I can pick up a catalogue of motorsport equipment I have in my office and find off the shelf springs with rates as high as 50 kg/mm (Eibach in this example).

I don't need tests to know that GT4's spring rate range is cut off short, simply an actual knowledge of motorsport.

How do you measure GT4 spring stiffness? Or you just based your assumption from spring rate value displayed on car setup and never verify wether that value really reflect real life value or not?

 

[Stunt Drifter]

Good lord you guys are technical! I tried to read all that but now my ibuprofin bottle is calling me.

i second that

 

[Scaff]

ok. But it seems there is missunderstanding, I mean spring rate is in the equation primarily because of it's elastic power.

Yes a missunderstanding exists because you said...

IMO, stiffer front spring will make the understeer problem worse. If we set front spring stiffer, the load transfer on front end will happen faster (relative to the rear). Faster load transfer will result in faster front tire overload. This happen only when the load transfer still in progress.

...and still have yet to illustrate in any substantive way how this would occur, the (to use your term) elastic power in a spring stores energy and releases it, it does not resist the force in the same manner as the damper (how could the elastic force resist itself - if it could we would not need a damper). Resistance in springs results in roll resistance, hence the reason why they effect how much the suspension moves under load transfer and why the principal effect is how the load is distributed between the tyres.

Nothing you have posted supports your claim that an increase in spring rate will significantly affect load transfer speed, the formula you posted does not, and the quotes I posted from Skip Barber completely refute it.

For this to occur in the manner you suggest the damper's resistance force would have to be so low as to make it almost totally ineffective - under damping of a ludicrous degree.

I have already described in great detail exactly why stiffening the front strings will increase a cars tendency to understeer due to the changes it causes in load distribution (as a result of changes to roll resistance), I have backed this up with numerous sources and you can find many, many more that cover exactly the same thing. The increase in understeer from stiffer front springs being a result of a change in load transfer speed rather that the (very well established and proven) change in load distribution makes no sense at all.

You are simply being to pig-headed to admit you are wrong and just throwing theories and formula around in an attempt to confuse people, and to be honest you should know better than this by now.

It is not about damper damping force vs spring rate damping force. It is about damper damping force vs spring rate elastic force. I am rather surprise that you never seen an equation like this.

Uhh I know and how the hell would you know if I had seen that equation before or not, do not start with the cheap shots again suchayo, I will not tolerate it at all.

That formula is an equilibrium in one degree of freedom suspension modelling. In this modelling, what is calculated is the damper damping energy, spring elastic energy, energy from road/wheel, energy stored in body.

All that link does is prove you can use google to search - it serves no point.

Agree that spring damping is minor to damper damping, but spring elastic is not.

Once again not news at all, but that's not what you are claiming. Changes of speed of load transfer come from resistance in the system, elastic power will not supply a great variance in this, but dampers will (keep in mind the purpose of one is to support load and the other is to resist the movement of the other). For this to occur in the manner you suggest the damper's resistance force would have to be so low as to make it almost totally ineffective - under damping of a ludicrous degree.

Agree. But this is how I see it:
damper is same, energy is same, spring is the only one changed:

soft spring make the suspension moves 2 inch.
stiff spring make the suspension moves 1 inch.

wiki:


more force received by stiff spring. More force transfered to tires.

Again as a basic principal I have no problem with this, but it goes no way towards supporting your claim. For this to occur in the manner you suggest the damper's resistance force would have to be so low as to make it almost totally ineffective - under damping of a ludicrous degree.

Correction:
spring rates in GT4 has so much wider range than the available damper range that they are the most noticeable factor in change of speed of load transfer.

I already mention that at low spring value, damper do it's job.

Correction, great, you actually get it right for once and then with no new info you change you mind. This is getting as bad as the whole reversed damper thing, you are posting opinion as fact, with no substantive evidence (other than misused formula) to support your claim.

I have posted two quotes from one of the leading race tutors in the world that clearly state what is correct. I could easily post numerous (and I am talking well into double figures here) quotes, links, SAE tech papers, lectures, seminar info, etc that say the same thing and discuss in varying levels of detail the effects of spring rate changes on the balance of a car. Guess what, every single one of them discusses the effect of spring rate changes changing the way in which the load is shared by the tyres as being he reason for the change in handling balance. Not a single one of them discusses, at any point, that the change in balance is caused by changing spring rates effecting speed of load transfer. I do however also have numerous papers that do discuss how dampers effect the speed of load transfer. Are you saying that every single one of these is wrong and you are the only one who is right? Do the authors of these articles (from the world of automotive design and motorsport) have an incorrect view of suspension behaviour, and that you are in fact correct and they are wrong? I ask because it certainly seems you are claiming that.



Now I have not strictly dismissed what you are saying as impossible, but it is totally improbable for any car.


You seem to be forgetting that for damper resistance to be so low for this to occur that the spring oscillations would be totally uncontrolled and the sprung mass of the car would be wobbling like a jelly on the suspension. Would you care to explain exactly why this is not occurring yet you still maintain that spring rate can become the main factor in speed of load transfer?

Do you actually believe that damper modelling in GT4 is that inaccurate?

If we can remove damper and stabilizer, would this make the test not void anymore or are there still other thing to consider to make this test totally void?

If I am not mistaken, this gamesave should has a abnormally bouncy MX5:
850hp MX5 1800RS

This has another kind of bounce, baloon like bounce.
13kg '62 skyline, video showing bouncy behaviour (by PlayGuy).

I think by now you should know my views on hacked values and the use they have in even remotely accurate physics testing, I mean to you honestly expect me to take the results of a test involving a 13 kilo Skyline seriously???

How do you measure GT4 spring stiffness? Or you just based your assumption from spring rate value displayed on car setup and never verify wether that value really reflect real life value or not?

Once again you seem to have forgotten the work I have done in this area already. I carried out a test on spring rate vs wheel rate (following yet another of your opinion as fact posts) that clearly showed that spring rates in GT4 are close to accurate and act in a realistic manner.

That PD used real values for the spring rates and that they act in an expected way, combined with the testing I have done, does not lead to any evidence that they are grossly inaccurate, simply that the range is not as wide as we would expect from the real world.

Once again we are running into an Ocams razor situation here, you are constantly looking for the most far reaching and bizarre conclusions, most of which purely exist to try and support you dampers are revered theory. When the most straightforward explanation (and most likely one) is that damper values are not reversed in GT4.

May I remind you (and other who may not know) that you actually decided that GT4 had reversed damper values before you ever even played it!!!

 

[sucahyo]

I see no point of arguing anymore.

But I like to post the formula that I will use when the suspension is pushed by the body, 1 DOF, wheel do not vertically moving:

(power dissipated in damper) + d/dt (potencial energy received by spring) = d/dt (Kinetic energy stored in mass)

(potencial energy received by spring) = d/dt (Kinetic energy stored in mass) - (power dissipated in damper)

d/dt (Kinetic energy stored in mass now ) =  (same as before)
(power dissipated in damper now ) = (same as before)

(potencial energy received by spring now) = (potencial energy received by spring before) 
(average force now) X (distance now) =  (average force before) X (distance before)
(average force now) = ( (average force before) X (distance before) ) / (distance now) 
(average force now) = ( (average force before) X 2 ) / 1
(average force now) = (average force before) X 2

I'll wait to see how spring and damper tuning goes in GT5.

 

[Greycap]

I see no point of arguing anymore.

Neither do I. A perfectly good help thread has been turned into another stupid argument war because one people thinks he's right despite being proved wrong. You play GT4 with a PS2, that's an improvement. But saying that the controller makes no difference is such utter bull**** that it leads me to thinking that you haven't tried out the different controllers.

With the DS2 the only thing you have to trust is the visuals and the sound. Now, get a DFP or even better, the G25. You will feel every little change. Stiffer dampers slow down the weight transfer, softer make the car distictively more wallowy. The difference is even more pronounced on curbs, a car that has a tendency to become an airship when hitting a curb can be tamed by softening the damper. In my opinion, this is a very clear indication about the settings not being reversed.

*puts on the Nomex suit*

 

[Scaff]

I see no point of arguing anymore.

I have to echo Greycap's sentiments here, this thread descended into farce because you seem to have a major issue with accepting when you are incorrect.

No one has a problem with discussing a theory, but when significant evidence is presented simply arguing because you don't want to be wrong is not constructive in any way at all.

I had a good look through my old Mark Ortiz newsletters earlier today and managed to find what I was looking for, a very good paper on suspension reactions, particularly in regard to the subjects discussed in this very thread.

I have attached a .pdf copy of it, but do want to quote a couple of parts of it.

So shock forces are complex. Sometimes our dampers create spring forces. Sometimes we can’t predict their behavior just by knowing their velocity.

Spring forces can also be complex. In leaf springs especially, there is damping in the spring, mainly from inter-leaf friction. In some large vehicles, with many leaves in the springs, this effect provides all the damping; there are no shocks. Even coils and torsion bars have some internal hysteresis. They will heat up as they flex, and they will come to rest after a number of
oscillations, even in the absence of external damping.

There is also friction in all the pivots in the suspension and steering, and there is friction in the sliding contacts in the shocks.

So we get some damping forces from our springs, and from other components in the system.

So exactly as I have maintained from the start, overlap in reactions occur between springs and dampers, and springs can and do have damping forces, and these can be significant in leaf springs (again as I said). Its for this reason why I differentiated between coil and leaf springs.

What then follows in the newsletter is a very lengthy and detailed explanation of spring, damper and anti-roll bar reactions throughout each phase of a corner. Guess what, each section of that deals with the springs effecting balance through roll resistance (the visible effect of which is a change in how much the suspension moves) and dampers effecting balance through changes in speed of load transfer.

Allow me to quote an example of this (I know its lengthy, but it does give a good example)

Part One, or early entry – braking increasing while turning in: This may or may not happen at all. In oval track racing, it is very common. In road racing, braking force more commonly reaches its maximum while the car is still running straight.

The car as a whole is accelerating rearward at an increasing rate, and accelerating laterally in the direction of the turn at an increasing rate. Angularly, it is pitching forward and rolling out of the turn.

Its roll displacement is outward. Its pitch displacement is forward. Its roll velocity is outward. Its pitch velocity is forward.

Therefore, the outside front suspension has a compression displacement, and a compression velocity. The inside rear has an extension displacement, and an extension velocity. Without more information, it is hard to say exactly what the displacements and velocities at the inside front and outside rear are, but they are relatively small, because the effects of roll and pitch are subtractive at those corners.

Consequently, spring and damper changes at the outside front and inside rear will have the greatest and most certain effects on the car.

Taking springs first, the important principle is that a stiffer spring creates more load change with displacement change – not necessarily more load. So a stiffer outside front spring increases load at that corner (negative displacement, positive load change), and at the inside rear, and correspondingly unloads the inside front and outside rear. This adds diagonal percentage, which tightens the car, or adds understeer.

A stiffer spring on the inside rear creates a bigger load decrease with displacement change. That translates to less diagonal percentage, and a looser car (more oversteer or less understeer).

A stiffer front anti-roll bar creates a positive (extension) force at the outside front, and an equal and opposite negative (compression) force at the inside front. This also creates equal and opposite load changes at the rear – more load at the inside rear, less at the outside rear. Result: more diagonal percentage, tighter car (more understeer). A stiffer rear bar does the opposite, and loosens the car.

As for the dampers, if we stiffen the outside front low-speed compression valving, that adds a positive (extension) force at the outside front, adding diagonal percentage and tightening the car (adding understeer). If we stiffen the inside rear low-speed extension valving, we are creating a negative (compression) force at the inside rear. This reduces diagonal percentage and loosens the car.

Important things to note regarding the role of the dampers:
1) When the suspension velocity and the suspension displacement are in the same direction, stiffening the damper and stiffening the spring have qualitatively similar effects on oversteer/understeer balance.

2) Contrary to a very common misconception, stiffening the dampers does not slow down or momentarily reduce the load changes at the outside front or inside rear – these load changes are sped up, or are momentarily increased. Spring loads are momentarily decreased at the outside front and increased at the inside rear – in other words, spring load changes are momentarily decreased by the shocks – but the effect on tire loads is the opposite.

3) If the low-speed valving is soft and the velocities are small, the damper forces may be relatively insignificant.

You see exactly as I detailed, while some crossover occurs between these two, the dominant roles of these components always takes place.

Take some time to actually read the newsletter and actually ask questions if you want to discuss it, but please don't come up with your own 'interpretations' and then claim them as fact. Hard as you may find it to accept I do know what I am talking about here.

But I like to post the formula that I will use when the suspension is pushed by the body, 1 DOF, wheel do not vertically moving:

(power dissipated in damper) + d/dt (potencial energy received by spring) = d/dt (Kinetic energy stored in mass)

(potencial energy received by spring) = d/dt (Kinetic energy stored in mass) - (power dissipated in damper)

d/dt (Kinetic energy stored in mass now ) =  (same as before)
(power dissipated in damper now ) = (same as before)

(potencial energy received by spring now) = (potencial energy received by spring before) 
(average force now) X (distance now) =  (average force before) X (distance before)
(average force now) = ( (average force before) X (distance before) ) / (distance now) 
(average force now) = ( (average force before) X 2 ) / 1
(average force now) = (average force before) X 2

Very nice, but it serves no purpose at all here. A diagram and formula without reference and context has no use at all.

I'll wait to see how spring and damper tuning goes in GT5.

You are not the only one, but I do hope that this time you will wait to actually play it before making your mind up on how they work in GT5.


Regards

Gideon

 

[Parnelli Bone]

i second that

Make that two doses of Xanax and a shot of tequilla on the rocks!

 

[sukerkin]

Many thanks for that PDF, Scaff, that's a nice piece of writing on the subject that I didn't actually have before 👍.

As (used to be) common knowledge around here, I'm a huge advocate of using the dampers to dial a cars behaviour in as I've ever found them to be the most effective method (once you have the other major components in something approaching the right ball park ranges).

One thing I particularly liked in the quoted part of the article is the explaination of what is happening when you stiffen the dampers to a certain point and begin to 'bypass' the springs altogether so that energy transfers more quickly, regardless of what is happening to body-attitude.

I tend to use this as a 'quick fix' (stiffening the front bound) if I'm finding that braking performance is sub-par because the fronts are locking up i.e. throw more weight onto them more quickly and see if that does it .

 

[Scaff]

Many thanks for that PDF, Scaff, that's a nice piece of writing on the subject that I didn't actually have before 👍.

As (used to be) common knowledge around here, I'm a huge advocate of using the dampers to dial a cars behaviour in as I've ever found them to be the most effective method (once you have the other major components in something approaching the right ball park ranges).

One thing I particularly liked in the quoted part of the article is the explaination of what is happening when you stiffen the dampers to a certain point and begin to 'bypass' the springs altogether so that energy transfers more quickly, regardless of what is happening to body-attitude.

I tend to use this as a 'quick fix' (stiffening the front bound) if I'm finding that braking performance is sub-par because the fronts are locking up i.e. throw more weight onto them more quickly and see if that does it .

Glad you liked it, I've been a big fan of Mark Ortiz's since he started writing for Racecar Engineering quite a few years ago.

I found a place with a wholeload of stuff you may be interested in (I will PM you the link), including a load of older Ortiz newsletters. I stumbled across it when I was looking to replace mine after my hard-drive went pop a few months ago.

I find it interesting (but not surprising) that you are also aware of the load transfer characteristic of over-damping and its ability to effectively bypass the springs, as a certain member has accused me of making that up in the past.


Regards

Scaff

 

[Formula1 Junkie]

one thing I would try...
Dont apply brakes during cornering. Brake before you get to the corner, coast through or with mild power, and exit with all she's got.

 

[Rotary Junkie]

F1 Junkie: Methinks this thread was resolved. :/