I put the 70mm TB back on, let me tell you the butt dyno says more power! The car went crazy fast and the tires have a little less grip in 1st and second now despite the ATB differential!
The turbo really likes it, I can really tell a difference under acceleration.
BTW unrelated, but I think I figured out why my dyno runs were all at 5.75 psi instead of the 6.5psi that I had before that. The wastegate spring is set at 6.5psi stock but I have the intercooler in there now and I'm sensing my boost pressure at the vacuum ports in the manifold.
This probably means that there is a 0.75psi pressure drop across the intercooler now that it is installed. According to the book MAximum Boost, IIRC it says that intercoolers with a pressure drop of 1 psi or less are good, obviously with less being better for racing cars. I think 0.75 is pretty good for a street car.
The intecooler I have is a spearco made unit from another car that I picked up used. Keith at streetflight helped me figure out the best way to fit it and then he did all the welding on it. It looks quite good I think. I will take some pictures tonight, but again, I have no way to host them right now so I'll email some on request for those of you looking for ideas or just curious.
Next step is to design&build, or buy a boost pressure regulator to up the boost.
I'll eventually be starting to add little goodies to my system to make it better and better.
