no water went faster and with detonation?

[white90]

i went to the track tonight, made a run and had some detonation, I pulled some timing and detonation was gone, i ran lean on a run, so i upped my rear jets. i make a significant jump, 88s to 94s. Well i ran it checked a plug and it was good, ran again with the water off and checked the plug and no detonation, it ran faster without the water and with out knock. What should i do now, l have the timing down perfect but i still want to run the alky. im running 24* timing on a 383 supercharged 142 blower and a holley 750. should i bump the timing to 26 or 28 and run the alky. how much hp would that offer. thanks guys