Suspension Paradox?!

  • Thread starter Evo Power
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Evo Power

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This is something I've been noticing since GT4...

Comon sense says that, in simplified way, a softer front suspension in relation to the rear would dial in some more grip for the front wheels, geting rid of some of the understeer, while the opposite would result in... Well... The opposite: some of the oversteer would go away. But in the twisted world of GT, it seems to work the other way around: a stiffer front end results im more oversteer, and a stiffer rear end results in more understeer, especially if the front/rear difference in spring rates is extreme, like 12 F 4 R... WAT

Can someone shed some light over this, please?
 
Softer spring rates on the front do reduce understeer, you will have to take account of the weight distribution of your car and your ride height.

To sum up basically:
Front softer: Less understeer
Front harder: More understeer

Rear softer: Less oversteer
Rear harder: More oversteer

But with a lower ride height you will need to stiffen the springs to stop the car from bottoming out on uneven surfaces.

There are upsides to softer values, for example it will let the car keep traction on bumpier surfaces.

If youre in an RR car like the Yellowbird, you will need stiffer rear springs, but if you lower the ride height to the minimum you will need to stiffen them further.

Odd things can occur at extreme values though.

To get it right i tend to reset to default, set a few laps then try a notch or two higher or lower depending on what i feel is needed.
 
You're thinking is sound. More compliance leads to more mechanical grip.

I haven't tried any tuning, but I before I do, I will test out sway bar settings with comfort hard tires...that should show steady state handling traits pretty quick.

I'm at work for a couple more hours, if you're at home, give it a try and see how the game responds.
 
Evo Power
This is something I've been noticing since GT4...

Comon sense says that, in simplified way, a softer front suspension in relation to the rear would dial in some more grip for the front wheels, geting rid of some of the understeer, while the opposite would result in... Well... The opposite: some of the oversteer would go away. But in the twisted world of GT, it seems to work the other way around: a stiffer front end results im more oversteer, and a stiffer rear end results in more understeer, especially if the front/rear difference in spring rates is extreme, like 12 F 4 R... WAT

Can someone shed some light over this, please?
Click to expand...

Tire loads.

If the outside front tire is being overstressed, softening the front will cause more understeer rather than inducing oversteer. The same is true for the rear.

Stiffening the front suspension will reduce the strain on the outside front tire and shift said strain towards the inside rear. Stiffening the rear shifts strain from the outside rear to the inside front, etc etc.

If a car beats up the outside front for example, stiffening the front suspension will help reduce this. If the car is just naturally understeering without either end having an excessive slip angle, THEN stiffening the rear will help solve it.
 
Go and read Scaff's tutorial on tuning. Its like tuning-101, all basics covered there! If you wish for more info you can search for calculations of weight transfer and brake balance etc on google - for the most part the variables needed for the calculations are available in the telemetry/replay (except for height of centre of gravity) which you'll probably have to guess... But nevertheless, the basic premise still applies.

By the way, you should start tuning aerodynamics before anything else because they only affect one variable unlike the suspension. Similarly but in a different fashion, anti-roll bars, camber and toe settings should be done last.

Hope this helps with your tuning method.

Cheers
 

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