Being brought up in the motocross scene Im fairly familiar with porting and polishing how ever.... Its something you need to fully understand. I.e how Flow work , turbulance, Flow test etc etc its not as straight forward as shaving a bit here and there. You can very easily make things alot 'worse' than the factory castings.
Although I cant see how you can port a TB ?? possibly bore it out a fraction or match it to the intake plenium!?
