I spray from first gear to fourth gear and even at launch...

If your car is lowered and you have stock axles and are shooting a decent amount of nitrous 100+ shot of n20, it might not be a good idea to shoot it off the line... I can just see axles snapping.

Just shoot the nitrous when you KNOW you've got traction and then just every gear and from then until redline... just an FYI, slicks are very helpful at the track