Dont want to insult your dads competence but this is a highly flammable substance....
Common misconception, Nitrous Oxide isnt flammable at all, and contrary to popular belief, cannot explode in a Fast and Furious huge fireball stylee :lol:
Nitrous Oxide is an
oxidizer which means its a compound that will happily give away its oxygen molecules. And will only burn when there is sufficent fuel and heat to cause ignition.
All your effectively doing is adding extra oxygen to your engine, a second solenoid adds additional fuel, therefore you get extra bang

Remember regular atmospheric air is 27% oxygen, pure nitrous oxide will be at best 33% (N2O)
This is where the engine melting fear comes from. Again, get the system wrong and you will run lean and melt something, run rich and end up loosing power, washing the bores and then wreck the cylinders!
As most will know you dont need nitrous to do most of that either
Nitrous isnt hard to fit. You need to have an idea of electronics for connecting the power, controller and solenoids, and mount the jets in the intake. By no means should you so this on the car! As you cannot risk getting debris in the cylinders! Then you need to mount the tank in the boot and run some pipes.
Most of this can easily be acheived in a day if you take your time and dont go ham fisted at it
