The H3 already has the equivalent of dual rate coils. The jounce bumper, or bumpstop, is very compliant and is an integral part of the total spring rate. It compresses significantly when you flex up the suspension. Your torsion bar provides one rate and jounce bumper provides about two more once the arm makes contact. You'll notice the bumper has that necked down section? That is where it compresses very easily. I believe that is supposed to be the brake dive section. Once that is taken up its resistance to compression increases much more. When the lower mushroom hits the seat into which it sits the bumper will seriously resist compression.
I can see where the engineers were going with this I think it's a good idea. However, like most OEM setups, it's middle of the road as far stiffness vs. flex.
A properly designed replacement jounce bumper could essentially be the trick but I haven't had a chance to fab up my design yet.
That said, if you add a winch/bumper, the static load will be higher and a stiffer torsion bar would make sense there.
One thing to note about shocks. They affect the rate at which the suspension moves. Viscous dampers like shocks provide more resistance based how fast you try t make them move. Since brake dive doesn't compress the suspension at a very high rate of speed and tends to hold in a position for a length of time the shock will have little affect on total dive.
Frank
