According to the words I've read...Wheat malt adds protein to the brew which aids head formation and retention.
The ratio to sugar I'm not sure of,but that is worked out by comparing the fermenability of sugar and wheat malt. I think you use more malt
I've only ever used cane sugar or dextrose for priming (oh, also CO2 now that I've got the kegging up and running ) but looking at some of my old notes I see that the ratios are:
Corn Sugar 1.15
Now I'm not sure of the absolute fermentability difference between Wheat Malt and Barley Malt, but I'm guessing that given it's not quite so fermentable as Barley Malt, that you would have to use about twice as much as you would for cane sugar.
I'm also guessing that if you're using Wheat Malt, then maybe you're working on a Weisse or Wit or something in which case, given the higher carbonation normally required, means adding a little too much is not all that bad :huh: