i've done the air filters bit to death along with custom TIPs and i'm still not happy with my results yet. i have a 850bhp huge 100mm Jetex cone to fit soon.
Stock box and paper filter..... not bad with consistant results
Stock box with green panel filter........ slightly less than above.
XL Dynatwist cai....... a little less than above (filter cone is just too small)
XL Dynatwist as open cone........ not much of an improvement.
400bhp large jetex..... very good and at leat 6g/sec ahead of any of the above.
But heat under the bonnet does reduce the g/sec of the Jetex set up after the first run.
A custom tip will allow you to point the maff toward the front of the vehicle, then we need a diablis type solution which will flow the air directly into the maff and then the turbo.
Cones suck the air through 90 degress (side on) which kills velocity. I have a custom maff housing which although reads less than true due to the dilution of air flow across the sensor, its not restricted by the stock maff air straightners which impeed flow.
I don't understand why you've upped your injector sizes though. Any fuellin adjutments are easily done with lemmingwinks.