yeah comes in gradually, not used it since my new setup, (need a refill) but i had it setup to start at 10% after a 0.5 second delay on full throttle (all this you can change yourself) and ending at 60% (100 shot kit) highest i have even ran it 80% and it scared the sh!t out of me, gonna get my new clutch fitted and see what its like with this new setup (will double up on underwear for this one)
if you are thinking of heading down this route, i would recommend changing the plugs for at least a grade higher than standard and using high octane fuel (i use ik22's & Vpower/Tesco 99, just my preferance,also serviced while i was at it)