You should use tires that can sustain optimum pressure. Each driver picks it up individually. General rule says that the lower the pressure, the greater the contact and thus better grip. There are special tires for drag Racing (slicks) and conventional tires cannot compete with them.
Before starting a race, we have to increase the outer tire temperature (as they say it is necessary to warm up the bus). The higher the temperature, the better will be the grip of your vehicle. The easiest way to warm up the tires is to create increased friction between the wheels, spin the wheel in simple words. Preheat the tires are other ways, but this method is the fastest.
Reducing vehicle weight will give you further dimension above the other racers. The first thing you can do is to remove all the unnecessary equipment from your cars: spare wheel, seats, interior panelling etc.
Improving aerodynamics dragster will certainly help you in getting ahead from the racers because any car after 100 km/h takes more air resistance. Given that the average speed of the car is usually 200 km/h, drivers should take great care of how to improve air resistance.