Andy Farnell has a fantastic book called Designing Sound, which details theories of designing procedural sound effects, with methods in Pure Data. Here is a great quote from his practical on Electricity:
The sound of a spark in an anechoic chamber is almost an ideal impulse
(which is why spark gaps are used to do impulse captures), so the
sound of the ...
Ville, have you read this excellent article about Transformers sound design?
It gives some clues, but not much. What surprises me is that I have not seen Kyma mentioned in any interviews about the Transformers sound design. The movie has a lot of "...
I achieve those sounds in different ways. Ableton Operator, Reaktor, short resonant delay lines and so on. You may start with a simple FM synth, just a carrier and a modulator, and a square LFO on amplitude. Here is a simple raw example made with Operator: http://soundcloud.com/lucacapozzi/ableton-fun-transformers-sound