I couldn't find min req. on the net for S2. Does anyone know? (I am interested in installing it in the office - after all it's MY office :-) ).
I think it'll run on fairly low spec machines and you can up all the options to run on higher spec machines.
I'm sure I ran the S1 incarnation demo on my old 650MHz FX5600, 256MB PC and it looked OK.
A few more details I found:-
The minimum recommended spec is 1GHz with a recent graphics card, but it may run on lower spec PCs than that, so try it and see. AMD Athlon XP 1600+/256MB+ DDR/GPU with hardware vertex shading support is adequate for good LFS experience, any slower than that and you're going to have FPS problems with fullfield online races and more than 8 AI-players.