fast13b

I rebuilt my HKS racing wastegate and put in a yellow 10 lb spring because I run 15 lbs with my boost controller. The spring I removed was green, I don't know the rate of that one. When I get on the gas (with the EBC turned OFF) the boost immediatley and rapidly heads for the hills (I removed my foot at 20 lbs). After assembly of the wastegate I tried to push the plunger with both thumbs and could MAYBE move it 1/16". My thoughts are a) turbo too big (t04s 1.15 turbine TA51 .55 compressor), b) manifold wastegate runners too small (XS cast tangental). I know the turbo is too big for what I want to do but is it problematic is the question. BTW the motor is a 13bt and it is ported. Any ideas??