Take a look at my last post now that I edited to add pictures and a link.
Thanks Luiz
I have read the link indicated and i have understand that in order tu reduce the wearher helm and tiller tug i must accept that the rudders work with extra drag from turnig, and to achieve a straight course slows the boat.
I have understand that for the hobie the advantages to increase the mast rake are greater of the disadvantages to make to work badly the rudders.
This is not my case .... I want to reduce weather helm in order to make to work the rudders with the smallest drag.