Nitrous and timing q's

[fiveohpatrol]

Ok I know that when running nitrous, the timing should be retarded about 2degree's for every 50hp increase, this is what NOS reccomends.

Now is this just to prevent detonation or is there a power increase associated with it? Does the nitrous change the mixture to where it burns faster and will make more power with less timing?

Reason I ask is I finally made it to the track to try the nitrous, and forgot to bring a timing light. So it was set at about 15-16degree's. I heard no pinging at all (verified this before track day) and the plugs look fine after running it with the 100shot.

So will I actually pick up any power by taking some timing out of it? Or is it more of a precautionary thing?

Oh yah, and I'm using autolite 24's gapped at 0.040"

thanks guys