Do you know what your ideal timing is for that engine?
There is really only one ideal timing for a given engine and fuel burn speed. Once you find it you should be very slow to crank in additional timing.
You might back off the boost to the point you cannot create any detonation with any reasonable timing and then run some tests to find your best mechanical timing ( ie puts the cylinder pressure peak at the ideal time after TDC)
If you have a safe environment ( ie enough octane or low enough boost) find the timing where you basically find no improvement in power with added timing, then back off the timing until you can just detect a hint of power loss. (about 1% power drop) that is your minimum best torque timing, and is the safest place to begin tuning from. Leave your timing fixed at that value and start running up the boost and playing with fuel air mix and injection rate. Once you have a good combo sorted out, then "tweak" the timing a bit to see if the minimum best torque timing has moved some ( burn speed changes with boost -- faster as boost goes up, and slows down with more water injection). There is a zone near 12.2 :1 AFR that the engine is most prone to detonation. You may be able to both pickup power and reduce knock by leaning it out some now that you have WI.
Have you looked at your EGT's for you engine ?
The engine is usually most detonation prone just slightly rich of max EGT. You might want to back off boost a bit and then tweak the fuel mixture a bit and see how close you are to that critical fuel air mixture that makes the engine most detonation sensitive. In general aircraft they do a lot of tuning based on where they are compared to maximum EGT. The engine will have peak cylinder head temps (on an air cooled engine) when the AFR is slightly richer than max EGT so that EGT is 30 or so deg F cooler than max. Max power is usually achieved rich of peak EGT, at about 80 degrees F cooler than max egt. Max tendency to detonate is about 50 degrees F cooler than max EGT on the rich side.
In short you are generally most prone to detonation just ever so slightly leaner than max power fuel air mix. If you start out well rich of max power mixture and then start leaning it out to make big power on WI you will pass through this "island" of detonation prone mixtures before you get lean enough to really make good use of your WI.
Just some thoughts on things you might want to experiment with.
Larry
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