A slightly tweeked varient of the K03 then maybe? Someone had a reply back from Borg-Warner on the Vortex and that's what they said it was, the turbo is also intergrated into the manifold as opposed to bolted on. Didn't think you could get 260bhp from them and yeah, a K03 would certainly be running out off puff before then. Maybe it's a combination of the manifold design, direct injection and/or a slightly tweeked K03...
dont forget it s 2.0 with a different head to the 20v, shifts a lot of things like flow vs PR. similar to a KO3s i recon
