To GTB or not to
AO Silver Member
Join Date: Nov 2007
In turbo cars I guess the boost pressure is a better option for switching the water injection.
If you switch by throttle position, you might have problems, when you try to floor the car at very low revs.
About the power gains. If you car is on standard map, and you will only use the water injection (no methanol) there will be no power gains whatsoever. Because only colder intake air wont help you gain any power, (standard ECU is not limited by air, but by fuel injection and you cant fix that unless you make a remap).
You need more fuel to make more power.
Fuel is supplied either by methanol in the W/M injection (but that will only show if you use 50% mix and flood the engine with that mix with 250+cc/min nozzles, because the methanol has very low energy density compared to diesel), or if you car is remapped properly for W/M to allow higher quantities of fuel (standard remap wont do the trick, you will need to adjust it if your car is already mapped).
There might be a marginal drop in mpg, but the EGTs will go down dramatically.
140cc/min nozzle is a perfect choice for your size of engine.