aluminum rods vs. titanium rods: fatigue life

a friend of mine made a set of titanium rods for his funny car (note it wear out tooling left and right ) , but titanium doesn't grow with heat as much as the crank did . it lock up the crank on the burnout to heat the tires , so i would say cool if you go that extra mile with a titanium crank as well . what kind of use are you needing the material for rods ?