Will be fucking tough achieving the same sound from detuned saw waves...
The closest (which it probably is, as it used to be heavily sampled back then) is stabs of the mentasm noise just reverbed and delayed a bit. Also pitch bent etc... Google mentasm.wav try find a decent version of it. its also in this tune, which is fucking sick! http://www.youtube.com/watch?v=04O_eoMRbLI
I've tried to get the stems from my mate that entered the remix comp but he hasn't got them any more. I might DM Dub Phizix on twitter actually to see if he's still got them.