RJC controller and 38 Tial wastegate spring options

[GDNF2ET]

I have the RJC boost controller and a 38 Tial wastegate on my Talon.. What spring pressure do I need to have the quickest boost responce ? The Tial wastegate has a 1.0 bar spring in it now and there are 7 springs that have less pressure..The springs are $26.00 a piece and I would like to get some advice from someone who has this setup on a GN already...