Who told you water will burn? I assure you this is not the case! What it does is flash into steam, thus absorbing latent heat from its surroundings.
The point of water injection is to reduce combustion chamber temperatures, which allows you to run more boost/compression/ignition advance. It does not increase the octane of the fuel, but it has a similar effect. If you tune your engine accordingly you can see worthwhile gains, but I doubt it would be worth it on a NA 5M-GE unless it was heavily modified.
A nice side-effect of water injection is it keeps you pistons and combustion chambers squeaky-clean; it effectively steam-cleans the engine's internals every time you use it!
The point of water injection is to reduce combustion chamber temperatures, which allows you to run more boost/compression/ignition advance. It does not increase the octane of the fuel, but it has a similar effect. If you tune your engine accordingly you can see worthwhile gains, but I doubt it would be worth it on a NA 5M-GE unless it was heavily modified.
A nice side-effect of water injection is it keeps you pistons and combustion chambers squeaky-clean; it effectively steam-cleans the engine's internals every time you use it!