Think about it mate??
how much is a PBV going to cost? bout 110 quid! for this you might get about a 1-2 bhp increase (if your lucky)
your have already lost 5-6 bhp by foolishly using an induction kit which is the most stupid thing you can do IMO
if you want a fast motor then just use a s/s exhaust decat and hillpower chip and put the standard airbox back on with a performance element, this system on a willy engine will see you a good 15 second quarter mile. this is what all the dragstrip boys use!
the only thing after this that will make your motor any quicker is either a sealed induction kit, ie Viper 200 quid+ or head and cams 1000quid+
its your money fella so its up to you, but id spend it insted on a good xmas!
Jim