New Yaris owner wanting info pls.

[dac]

ok, ive just gettin my 99 Yaris GLS 1.0 last week and from driving a Rav-4 i must say it is fantastic, handling wise its like a little go-cart. and stops extremely fast! however im a bit concerned power wise, its absolutly brilliant for a 1.0 i must admit. but previously i used to drive a Rover 216 Bubble (as well as the rav) which had quick and easy mods like, bigger throttle body, cool air feed, alluminium plenum chamber, de-cat etc etc.
question is is, what kind of engine do i have? i used to tinkering with the legendary 'k' series engine, and how does it respond to certain mods?
o, and i belive the VVT-I is the equivilent to rovers VVC (variable valve control) is it not?
thank in advance, dac.