Are you going to be racing the car or driving it on the street? If you're not planning on racing the car, the module selector, crossover delay, and two step are useless. If you're planning on racing the car, the two step and selector will be good, but the crossover probably won't do you much good unless you are planning on racing seriously, and even then may not do you much good if your local track has a blinder to keep you from being able to see your opponents bulbs.
RPM module selector allows you to set the max rev limit on the car
Two step allows you to set a lower "temporary" rev limit, for example so you can floor the car at launch while holding the button and it will only allow the motor to rev to your preset launch rpm.
The delay timer portion of the box is simply that. You lift off the transbrake button, there is a delay between the time you lift off the button and the time the transbrake actually releases. Great for 'quick' guys that have a tendency to go red once in a while. Generally you launch the car off the top yellow bulb. You dial in 1.0xxx seconds into the delay, release the button at the hint of color on the top bulb, roll the throttle to wide open and hang on.
Cross over delay. You dial 10.00, your opponent dials 11.50. In a cross over box you enter HIS dial, and YOUR dial. As HIS top bulb comes on you release the transbrake button. Then get back on the button. Then as soon as YOUR top bulb comes on you release the transbrake button again. The computer takes the interval between the two dials, the interval between the two releases of the transbrake button and launches the car at the best of the two predicted lights.
