My experience with the traction control is as follows.
Going around slight corners and nailing it, the car will pull lose power and then accelerate once grip is gained again.
But in the wet the car will drop spark and the engine will 'strobe' (for want of a better word) for a second and then accelerate, at which point traction will be lost again, and then it will strobe again.
I think maybe in moderate losses of traction, the blade might close, butin big ones it drops sparky and really pulles the reigns in.
If it only works for traction control, I wonder it there is any merit in using it as a variable intake diameter type device????