thats cos our standard manifold dont flow to good mate bit of work but worth the upgrade id say
You just won't listen will you.. From the moment you got the car you have been trying to find faults that arnt even there. You have change parts that have never needed changing like intercooler, when bill mapped the car I said is the intercooler ok and he said yes its fine,the pipe work was fine also,I know this because I fitted it al and you had it smoked testedl. IMO your weeing your money up the wall. If your happy with the power then just enjoy what you have, I know the car was plenty fast enough (13.8 1/4 mile in road trim). Loads of people have told you the car is fine stop fussing.
The options are leave it and stop spending money pointlessly,keep wasting your money or if you want more power, like your mate said go big turbo.
I'd love to see some pics of the car though please