try:

raising the rear suspension so there is more weight over the front wheels
fitting adjustable TCA's so you can change the camber (i think it is) on the front wheels
learn to bring in the power gradually (which is probably the main point!...Sunny with 440hp in his fiesta managed to launch 0-60 in low 5's and 0-100 in 10's with worn road tyres!...no launch control, traction control etc etc just knew how to bring the power in)
depending on howmuch pwoer you are actually running...a strong LSD or something like a stage one g/box
also try making the front suspension lowish and soft and the rears very hard and high
also when launchin in first...i realised most the big HP FWD boys seem to change gear as the car just starts to spin....they let it spin a little to get the revs up and then change to second and let the grip come back and then boost take them off again....watch how Paul (red fiesta with 4.92sec to 60) launches
also if u are planning to do more mods to the engine...try shifting the power higher up in the rev range so u are actually moving before the huge rush of boost breaks the grip of the tyres...that way you will be wheel spinning but making a lot of ground at the same time
softer compound tyres

erm thats all i can think of off the top of my head as i gotta rush off to do some revision...

hope this helps and im sorry if any is wrong

bassboy