Originally Posted by Dropspeed
When you say control weight transfer can I assume that translates into increased traction? I have the mind set that when the front rate is increased more than the rear this induces under steer. Does that still hold true or are you increasing the rear as well?
A 5th Gen without understeer wouldn't be a 5th gen
We feel the 5th Gen is under-sprung up front from the factory. As balanced as the 1LE is, when you stand on the brakes the nose dives and the tail lifts. When you accelerate the nose lifts and the rear squats. A 1LE with driver and fuel hits the track at two tons. That is a lot of weight transfer. Too much transfer for any front wheel and tire that will fit in the fender well.
In a race car, we would default to a muscle car like rake with the thought that the car is light enough and balanced enough to benefit from the rake biased weight transfer. That isn't the 5th Gen. We find that increasing the front spring rate, lowering the rear in relation to the front, reduces understeer by controlling weight transfer and not overloading the front tires. There is a limit to the rate increase before it becomes a negative. That is why the 12kg front and rear is working so well for us and 14kg coils do not.
Keep in mind that the front spring rate is the front spring rate in a virtual pivot front strut while there is a motion ratio at work in the rear that reduces rate at the wheel, but you already knew that.