Torsion Bars... Best Diameter for a Lowered Street / Autocross car?

On the street, my 1.03 bars are not too big; maybe just right.
Going into a corner hot, the shocks drop the outboard corner onto the bumpstop, and yeah it can be a tad rough, but it flies around the turns pretty sweetly. The problem is that the 235/60-14 front street tires give up, and the car just skates over to the outside of the turn. But that's Ok, a lil gas and the other end skates too.
I learned to pick better lines, with lots of run-off space, and I get the back end out first, so it can push the front back to the chosen line,lol.
Street is all I know.

The 1.03 bars are not really stiff, but the shocks are old school 3-way Munroes set on hard, so they hammer pretty hard over speed-bumps that I rarely slow down much for. I mean, my seats have cushions so I gotta give them a workout too.