spring rate Setting higher value make spring soft

[ginji]

am i right? i read scaff's tuning guide it say front soft(lower value)

then i Set front spring 2.1 rear at 15.0 and test (i want oversteer)

but i feel understeer than mySetting(f 15 r 2.0) i want to know lower or higher that make spring soft

 

[stiggs]

the lower the rate the softer it is 2.0 = soft, 15.0 = hard

 

[ginji]

thank you

i set front 2.0 rear 15.0 but i feel very understeer i don't know why because scaff's guide say front soft decrease understeer rear stiff increase oversteer

my car fc gt

 

[VQuick]

Your setting of 2kg/mm is much too soft. You need to raise it in order to improve the sensitivity of the front end. However, do not raise it to the point that the front of the car bounces. That will just give you understeer again. You have to be balanced in your approach.

I don't know how much your FC weighs, but try something like 10kg/mm up front and 8kg/mm in the rear. It isn't a hardcore race setup, but by driving with it you should be able to get the gist of what we're talking about.

The next step is tuning your dampers to match your spring rates. Someone else can explain that, or if you're feeling industrious, you can look in the tuning guide.

 

[TS]

Add max downforce in the front and minimal in the rear (wings are an easy way) to make the car super loose.

 

[Scaff]

am i right? i read scaff's tuning guide it say front soft(lower value)

then i Set front spring 2.1 rear at 15.0 and test (i want oversteer)

but i feel understeer than mySetting(f 15 r 2.0) i want to know lower or higher that make spring soft

I'm not sure how carefully you have read my tuning guides at all, rather it looks as if you are simply reading the tables and ignoring the text, as I quite clearly say the following

To give an example of a potential problem, you may be tuning a front wheel driver car to reduce understeer. This can be done by making the front spring rate softer than it was; it does not mean that the front spring rate should be set softer than the rear.

and

Note: Great care should be taken with extreme spring rate settings as they can have unexpected results. Very soft rear settings can, for example, effect the tyres contact patches to such a degree that it results in greater oversteer rather reducing oversteer.

Extreme values of this nature do not work in real life and they don't work in GT4 either.

The problem can occur for a number of reasons, one is mentioned above and it's that of contact patch distortion, another than can occur is that a very soft setting will not be able to support the car under load transfer and the suspension can bottom out. If this happens your once soft suspension setting is now effectively solid (as it can travel no further) and you now effectively have a spring rate of infinity (which lets be honest is stiff to say the least). The result of this is a soft initail reaction that then goes very stiff as soon as load is transfered, and massive understeer is normaly the result if its the front end of the car.

Now I am not saying that GT4 directly simulated this happening, but it certainly does model the effect.

If you have read my example of a tune (and the rest of the guide) you will also note that I never make changes to the set-up of the extreme nature you have mentioned, it simply does not work.

Additionally I would be interested to know what your damper values are, as stiff dampers (high value) can, depending on the car weight and spring rate, reduce the springs ability to react. This effectively stiffens the spring rate and can also cause problems.

I would ask, did you set the initial spring rates based first on the cars weight and weight distribution and then tune it to the track surface, before using it to trim under/oversteer?

It certainly does not sound like it, yet this is exactly the method I suggest using in the guide. You can't just throw values at a care and expect them to work, if the spring rate and dampers are not first set for the car and then the track, you can't expect to be able to use them to balance the car.

I would recomend re-reading the guide fully and then following the example of a tune (pages 40-42), as this will help you a lot.

You should also remember that spring rates are not the only tool you have to trim under and/or oversteer, it will also depend on when it is occuring. Take a look at the corner breakdown (pages 8-11) which explains how a corner is made up and the different suspension settings that will effect it at each part.

Regards

Scaff

 

[sucahyo]

Higher spring rate value is stiffer.
The car that show this clearly is Subaru 360. If you set it's spring rate to low value it will osccilate slowly after meeting bump. Faster if high.
High osccilation value show that the spring is stiffer.

This is taken from wikipedia Springs (Physics Study Guide):

T is the period, m is the mass, and k is the spring constant.

Meaning:
Higher spring rate value in GT4 is stiffer spring rate

The way spring rate change the car handling behaviour in GT4 is complicated. People still have different opinion about this.

 

[ginji]

thank you all sir it my false

 

[Vision GT]

set the front and rear springs to lowest as possible. also set the stabilizer to lowest as possible. Then run it on a track, example: Tsukuba Circuit. Then after you're done with a few laps, watch your replay and watch how the car rolls. Then do another few laps with stiffen springs and stabilizers(sp?).

 

[ginji]

oh thank i will try