The Ripple Effect

I found this concept in a drumming book (Secrets of the Hand) and am applying it to piano. If you start a phrase with a few fast notes, the whole phrase will appear faster, so you don't have to lay four sixteenth notes, you could play just two and shift to 8th notes, and the effect will seem almost as fast because the listener's ear will be lagging behind.

You can also play explosively by moving suddenly into a faster sequence of notes and then resuming the slower subdivisions. I hear this a lot in Coltrane, when he plays at a slower tempo. Really fast runs in the context of a slow tempo have an explosive power to them that's a little different from the steamroller effect when everything is super fast.  Having space between phrases also can make them more explosive.