OK, it seems that the problem has been solved.
It is a leak in my exhaust ( a small one ) and the sound is equivelent to a turbo spooling up. Its pretty funny actually, but that just means im going to replace my exhaust as the next thing on my list.
Thanx to E&E Motorsports for looking out, ill have the work done as soon as I have cash!
http://www.e-emotorsports.com/