I use to shot peen the transverse torsion bars back when we were developing the old F-body... the pressure
and shot size varied based on the material you were working with.. with those torsion bars if they werent
shot peened they would explode at the bend every time when I would try preload then... the shot peen was
a stress reliever...we tried multiple sized shot and even different sized shot on a single bar.. the peening also
compressed the steel to assist the strength of the steel... also you can double peen or more... I also use
to shop peen (douple shot peen) my viper rods