RIC thanx for your reply i have found the N1 inertia setting in the .air file but it doesnt seem to affect the spool up rate. However i found my problem it was my fuel flow gain setting. IT WAS WAY TOO LOW
[TurbineEngineData]
fuel_flow_gain=0.000904 <-----------WAY TOO LOW

inlet_area=12.404000
rated_N2_rpm=29920.000000
static_thrust=17000.000000
afterburner_available=1
reverser_available=0
Thnx for your help though