Kind of hard to see in the pics but I have thinned the bar that holds the butterfly plate which should allow some more air in. I was going to change the screws holding the butterfly in for some countersunk ones which in theory should create a little less air turbulence but then I couldnt find and suitable screws (machine thread) in my box of bits. In the meantime I have countersunk the holes and will change the screws at a later date.
The butterfly itself is made of aluminium and I sharpened the edges of the plate with the tailing edge of the plate having a more curved shape to better enable the air to pass over it at part throttle.
Inside the body itself I flattened out the bumps and ridges.
Initial findings after fitting:
Car appears to have a very slight torque increase when moving off from low revs.
Engine seems to rev a bit more freely when you stomp on the gas from idling with little or no hesitation now.
I havent been on a long enough drive to see if anything else has changed yet but will report back.
Overall not a bad way to spend a couple of hours in front of the telly with a dremel.
I sense a MK 2 coming on