[parmas]

24-28C @ 16psi !! What is your ambient temp ?

These are good temps, are these with water injection on?

You will not hurt nothing if you increase 1-2 degree per run. Just don't keep advancing if you see the motor loosing power. Normally 5 Degrees of advance from beginning to end of injection should be needed for a 50/50 mix but that depends how much water/meth you are throwing.

Also you should know that the cooler the air mixture the more advance you need to complete the burn.

Surely advance is an issue here!