auto cross
I have 1.14" Sway-a-Way torsion bars which are advertised at 350 lb/in rate, the ride is much firmer than stock but still very streetable unless you live in a place with terrible roads covered in potholes.
Seems like the people who say "it'll rattle my teeth and compress my spine" never actually drove a Mopar with big torsion bars. It's really not that bad at all. I've driven and ridden in newer cars, some not even performance-oriented models that had a harsher ride than my Duster. Most smaller Asian cars ride like garbage in comparison. What's cool with stiff springs is you feel the road "smooth out" once you get to higher speeds, my Duster feels like it's on rails on the freeway but you don't feel the little bumps in the road once over about 60 mph. I just don't drive it as much as I used to because traffic increased a ton in recent years, too many morons and not enough room to have "fun". Plus Dusters are actually valuable now, to my disappointment.