The size of the turbo is a bit too large for the fuel you can run from the injectors.
The point is why have lots of lag with a T4 if you don't need to, get the same power on greens with a T34, which despite some bollocks spoken here will run to around 375/380, the last I saw was a T34, machined out T3 comp housing with a .48 housing and it made 377, on an engine dyno, repeatedly all day long forever.
It had in excess of 30 power runs, turbo was maxed out but coping no problem.
Anyone who thinks thier car with a T4 and 18 PSI is going to eat a stage three cossie on 25/27 is most likely on drugs.
The engine is merely an overglorified AIR PUMP, air = OXYGEN = POWER, all else being equal ie capacity, more air = more power simple as.
T4 are unbeleivable laggy, not good at all for a race car, where torque spread is the name of the game, yes they are faster when you get going, but by the time you get going the T34 car is gone away and finished the race.
Greens are capable of in excess of 600 BHP, but not with the ford ecu, it is antiquated, but does the job, bit like solid tyres rather than air filled ones!!
Consider a aftermarket ecu, and go batch fired as it would be even better at higher rpm.
tabetha