The_Pikeman said:
Right IIRC nos or nitros oxide is injected in with the petrol the oxegen in it ignights with the petrol causing a larger "explosion" causing more torqe ... also the expansion of the nos causes the air to become denser adding again to the power ......something like that anyway .... also I thought some nos kits were road legal.
-How.
Close. Just to nitpick:
The additional power created by the extra oxygen in n2o is miniscule. Remember that you're only getting one oxygen molecule for each two nitrogen molecules... However, the nitrogen does give a nice buffer effect in the combustion chamber - but the nitrogen doesn't burn and therefore doesn't add any more power, though.
The biggest source of power from n2o is from the temperature drop of the intake charge when the n2o changes state from liquid to gas as it's injected. The colder intake charge is more dense - more oxygen molecules per unit of volume - and thus when mixed with more gas makes a bigger explosion and more power.
That's important to note - when you inject n2o, you also need to add extra fuel. If not, the engine will burn extremely lean (read HOT) and destroy itself. Depending on the injection setup on the car (or even carb setup), a separate fuel system may not be necessary - as the existing carb/injectors may be able to recognize the need for the extra fuel and supply it correctly. But this only works with small shots - ~50HP. More than that and you really need to think about upgrading the fuel system to deal with it.
Matthew