Static test that dangerous described is an excellent way of determining the correct jet ratios, but doesnt very well work on cars with a lamda sensor as if they are in closed loop mode the eco tries to compensate for any inaccuracy in the nitrous jetting.

Mapping to a lambda/afr value isnt as easy as you might think as the nitrous portion of the intake requires a different AFR value (actually the term AFR then becomes misleading as obviously its not air!) the main reason for this is the lower percentage of nitrogen present which means that propotionally there is a bigger percentage of oxygen in any given number of molecules, and as the reading you get at a wideband is a percentage it doesnt take a genius to see why that throws things out.

The problem you have here then is that the reading you are wanting to arrive it is then a proportion of the air AFR and the nitrous AFR interpolated to a point relative to the % oxygen you are getting from each source, ie the bigger % power you are getting from the nitrous the more it effects the value, and as this changes depending on where in the rev range you are it gets really quite complicated.

Then you have other factors like the bottle temperature drops during a run which means that you need to lean the mixture off the longer you are on gas even at the same point in the rev range.

So if you were on a hill at 4000rpm and at full throttle and on nitrous the hill was so steep it held you at 4000rpm without accelerating it would mean that you would then have to lean it out over time even though you were at the same load site in your fuel map for the whole time!



With regards to timing, its not quite as simple as the 25% that Karl mentions although thats not a bad ballpark to work to, but its very dependant on the individual engine, ive had increases of almost 100% power from nitrous with NO ignition retard without ever introducing det.
The worse the intercooler on your car the more nitrous you can run, and (assuming the ECU ACT sensor is upstream of the nitrous) the hotter the external temp the more you can run without timing.

In fact if you are looking for the ultimate power output from an engine you can actually often ADVANCE the ignition safely, even on fairly large % gains.


ITs very dependant on the kit you use of course though and all kits are NOT equal, you did the right thing enquiring at wizards of nos, i would advise you stick to that path if you do decide to go for nitrous