lumbee1
Native American
That last pic tells the main story too Adam, very well for the tapered dual rate.
Theres a small amount of progressive rate in that last wind before the secondary rate, where it gives that little bit of softer rate before it goes to the full hard rate, but not that much the car feels "tippy" or unstable, with the shock package especially.
The softer rate open as you say for traction, but also for stability, when the vehicle is stretched out and near its limits, you have a softer rate exposed, which wont upset the car or make it move around corner to corner or side to side as much, because of the softer rate, but it will keep the tyre pressed into the traction surface. When your on the washboard roads, bad back roads etc though, you have a small amount of give as it increases rate a little for better on road ride. We also tend to go a slightly softer rate on the heavy one, but a slightly taller free height, so we can have a better unloaded ride quality as well, but the spring will sit at the required height at the rated load.
They are important factors in heavy touring and overland trucks to ensure they keep the rubber side down.
This pic illustrates that well I think, for anyone who has seen Cruisers drive across this, car rocking, left front wheel in the air, bumper dragging, Woody has stage 4 slinky long travel intermediate package in Gretchen for afew years now, and in the pic you can see how theres softer rate to keep tyres on rocks, and enough travel to keep them there, and as the car comes back onto the coils and they compress, the coil rate increases to prevent momentum getting a run over the suspension.
Yet you can go bombing in the dunes, being chased by a U4 truck, loaded, windows up, AC on, drink in the cup holder, smiling from ear to ear, when you have your 80 "off the leash "
That video would convince most to buy Slinkys immediately. With my Frankies Off Road springs and blown out Bilstein shocks, I couldn't maintain a 1/3 of that speed.
