NOS (actually a US nitros company), is N20. When injected it breaked down under the engines heat to create nitrogen and oxygen. This has the same effect as having a better flowing head as more air can get in. This allows you to increase the amount of fuel to be burnt with the increased mass of oxygen.
There are 2 basic systems, a wet kit and a dry kit. A wet kit is good for up to 200-300BHP and the easiest solution as it injects fuel and N20 into the induction system (after the air filter and before the inlet manifold) at the same time through a shared nozzle. A dry system injects nitro through a nozzle in the same place or drilled into the inlet manifold, and the increase in fuel is supplied by the engines own injectors which just spray more thn normal. It does this by using the N20s pressure to squeeze more fule through the fuel regulator. These are the basic s but there are many hundreds of systems.
the effect is hard to explain as the nozzle injects a constant flow of N20 at any given rpm. You have to understand that it feels fast at first because the given mass of N20 at say 2000rpm is being cut up into 2000 peices. At 6000rpm, its cut up into 600 peices, and thus, less gas in each cylinder and less power. Torque is increased massively at low rpm, and at max rpm, however much hp the kit is fitted with. You can bget computer controlled progressive kits which change the amount of N20 inected at different rpm, so it increases the amount of N20 injected at high rpm to sustain the torque and make best use of the high rpm.
very vauge and sorry be being wishy washy.
