My car seems to be very very slow off the mark, even stock VR commodores beat it off the mark (But of course the xr still wins . Does this seem right? Once it reaches 2000rpm then it decides to unleash the power.

there is a fair bit of weight difference.. your car has a 4 spd auto and no big turbo torque..

vr is lighter.. seem to have all their torque down low.. and a very short st gear.. hence why he gets you off the line.. but one the falcon is wound up.. the extra power of the falcon comes to play....

Is there any mods apart from a turbo that i can do that will give me better take off?

shorter diff gears would be the most effective way of doing it.
Hunt the wreckers for complete center from a BF 6speed (3.7:1)