Stiffer Spring Rate Question

So I was led to believe that a stiffer front spring allows a fwd car to get a little more loose around turns whereas a stiffer rear spring (relative to the front) will create understeer.

Now some recent articles are saying a stiffer rear spring will create more oversteer.

Track testing has shown me that tire psi also play a role in causing oversteer and understeer to some degree. I run 36F (hot) and 39R (hot) psi and car rotates much better this way.

My goals are:

1. Stability and grip on medium-high speed sweepers
2. Great turn-in, lift-off oversteer for the tighter transitions.

I also noticed that most "track" dedicated coilovers come with higher rates for the rear then the front.

But KW Clubsports and AST4100s come with heavier front springs than rears.

I was wondering why the differences?

How would stiffer front springs make the rear rotate better, if anything it creates more understeer. The dg springs for example are actually softer then stock in the front and stiffer in the rear. Also setting the rear too stiff would make it feel twitchy during high speed turns, but offers better turn in at low speeds. It's all a balance, there is a lot more then just springs.

What tires are you running, you'd probably get more speed if you dial in your tire pressures and temps.

It's common knowledge that stiffer (than before) springs on one axle increase load
and reduce grip of this axle.

Same with sway bars: fit a stiffer rear bar for increased front grip.

Better turn in needs stiffer front springs though.

Then would something like the KW Clubsports create more understeer since the front springs are much stiffer?

The KW Clubsport springs are not MUCH stiffer on front.

FwIk Golf/Rabbit/GTI fronts are 90 N/mm and rears are 70 N/mm.
For A3 Sportback fronts are 90 N/mm as well and rears 80/mm.

Main springs only. There some very soft helper springs as well,
but they seem 'closed' when not jacked up.

Many suspension kits offer far more difference front/rear !!

penpal said:

How would stiffer front springs make the rear rotate better, if anything it creates more understeer. The dg springs for example are actually softer then stock in the front and stiffer in the rear. Also setting the rear too stiff would make it feel twitchy during high speed turns, but offers better turn in at low speeds. It's all a balance, there is a lot more then just springs.

What tires are you running, you'd probably get more speed if you dial in your tire pressures and temps.

Click to expand...

I run starspecs and rs3 for tires. My suspension is kw v2 with neuspeed front and rear bars. Tire pressure is usually 36F and 40R hot psi.

When i had rear bar only car rotated better buy was unstable through fast sections around the track. So i got the smaller front bar and although my car doesnt rotate well as before, car is more stable. Feels like its slower than beforr but my lap times are better.
Im on a quest to find the best track oriented coilover that gives me good turn in, dampening, high speed stability and excellent rotation.

What coils do you guys think would best suit my setup?

staynhome29 said:

I run starspecs and rs3 for tires. My suspension is kw v2 with neuspeed front and rear bars. Tire pressure is usually 36F and 40R hot psi.

When i had rear bar only car rotated better buy was unstable through fast sections around the track. So i got the smaller front bar and although my car doesnt rotate well as before, car is more stable. Feels like its slower than beforr but my lap times are better.
Im on a quest to find the best track oriented coilover that gives me good turn in, dampening, high speed stability and excellent rotation.

What coils do you guys think would best suit my setup?

Click to expand...

Entirely logical finding, and really the reason why on a real race car they run different setup for different track. For autoX you will tend to run a lot more aggressive rear stiffness bias if you can to quell the front drive car's characteristic to understeer. Lots of tight corner, lots or acceleration and braking, but the speed is not high enough to bring momentum and rear end grip into play, so your priority is to get the car to rotate and point and the right direction. A nervous car thats ready to change direction means its going to be more responsive for a tight and twisty course like autocross. Once you go faster on the bigger track, that nervousness translate to instability and thats more detrimental....