Finale 3D has a set of default prefire times based on Size. You can see this in action if you use the menu item ‘Effects > Create effect…’ For example, if you type 1″ Red Peony, you will see Finale 3D will automatically populates a prefire time of 1.59s. If you change the size to 1.75″, the prefire will increase to 2.05s, etc.

You can override the default prefire values by explicitly adding prefire to your input description. For example, 1.75″ 2.25s PFT Red Peony. In this example, the 2.25s prefire (PFT) overrides the default value of 2.05s.

The Finale 3D definition of prefire is “the time from firing system ignition to the effect time that is synchronized to the music.” For shells, prefire = lift time, but if the shell is a consumer shell with a slow burning fuse, then the default prefire values does not automatically take that into account. Visual Descriptive Language (VDL) has additional terms to support this scenario. For example, let’s say your 1.75″ consumer shell has a 4s Visco fuse, then a 2s lift time from launch to burst. The 4 seconds of Visco fuse is a “Delay” (DLY) and the 2s from launch to burst is “Lift Time” (LFT). The full time from firing system ignition to burst is “Delay” DLY + “Lift Time” LFT = “Prefire Time” PFT. Therefore, to make an accurate simulation, you could type 1.75″ 4s DLY 2s LFT 6s PFT Red Peony.

Documentation article on prefire: https://finale3d.com/documentation/prefire/

When it comes to timing, there is no substitute for knowing your product.