ParametricPlot3D[{2 t Cos[t],2 t Sin[t],8t},{t,0,20 Pi},ImageSize->500]

Manipulate[
ParametricPlot3D[{a t Cos[t], a t Sin[t],b t},{t,0,20 Pi}],{{a,3},1,5},{{b,5},-5,8}]