Also if you after 700bhp c2 motorsports now do a pro maf setup so why go to the expence of standalone. i use there 630cc set up with 4" maf and it works brillient. it runs totaly like stock till you hit 3 grand then boost comes then at 4 grand then all hell brakes lose and thats just at 24 psi
allot of the ford guys use omex never herd any reviews tho good or bad, sp turbo use dta with some impressive results, also 034 motorsports do some nice bits of kit and they have lots of gt35 base maps to choose from using different boost levels.
personaly i think you could bore it out to 83mm practicaly a 3 ltr and not have to worry about the block cracking as engines such as the i5 20v motor have ran upto 1200 bhp and the gap between the bores in 10 times skinnier.
There is some one one the s2 forum thats done a similar thing in a mk2 golf. he has turned it into a quattro using all the s2 running gear the only difference is he has used the i5 20v motor which is actualy longer.
i have 38mm waste gate .5 bar fine 1 bar fine 1.5 bar fine 1.7 bar fine oops there goes my drive shaft. Try using a 1 bar wastgate spring instead of using the emerald to control the boost.