suspension vs ARB to combat understeer/oversteer

I'm pretty comfortable with setups and what everything does, but one thing that's always stood out for me is whether to adjust ARB or suspension to counter understeer / oversteer as they seem to do the same thing.

Lets say I have an understeering car, what will be the difference in handling of softening the front suspension vs softening front ARB. I can't tell the difference.

 

ARBs only affect lateral behaviour, while springs have an impact on lateral, longitudinal, and vertical dynamics.

 

Right, but the question remains when would you choose ARB's over suspension adjustment and vice versa?

 

If the car is fine under acceleration and braking in a straight line and over bumps I wouldn't mess with springs, since I can isolate the cornering balance with the ARBs.
The opposite is not true though.

 

That makes sense, thanks. btw love your signature, something people say all the time that bugs me so much! Another one that gets to me is 'I broke too late'.... aaaaahhhhhhhh!!!!

 

Next you should do a similar one about "fun" and "funny."

 

You definitely need to think about what sort of understeer/oversteer you're getting ie entry, mid corner, exit, high speed, low speed and so on. Different changes are needed for all above situations. It's often not about arb or springs.... camber, toe, bump, rebound, aero are all in play here. Think about weight transfer in the car also. Oversteering into a corner... you could reduce front camber or stiffen front arb, when in fact you need to stiffen front suspension due to diving under brakes. Exit understeer, you may soften front bar to increase front grip when in actual fact the car is squatting in the rear under power, unloading the fronts and you actually need to increase rear bump. Sorry to make it more complicated but there's a lot of factors that can cause handling issues and adressing the root cause rather than just trying to increase front or rear grip is the solution.

 

In my high opinion...

You got to use common sense with the law of inertia(newton law) when it come to spring rate to obtain balance during acceleration & braking based on the weight distribution of the car to obtain balance.(Inertia is the resistance of any physical object to any change in its state of motion.)

More mass(resist more), more spring rate, less mass(resist less), less spring rate.

If you combine both they will compress at the same speed, based on the mass.

The G force of multiplier of the requirement of the physical object to any change in its state of motion to support. You can use the current brake balance setting as a reference. It's a bit of a guess work around.

You can use the damper to adjust the speed since in most case braking force is higher than the acceleration force which lead to slight imbalance.

If the car is correctly setup, the car lap faster & also easy to drive regardless how bad is your inputs.