I just set up Storm Racer G and it just worked without any special configuration. I have read other people saying the same thing, no settings needed, it just works.
Maybe make sure you launch the game at the right times so that one PC isn't ahead or behind the other when it gets to the network check screen. I don't know if that would matter but that screen doesn't last long and some games are picky about timing for LAN. EDIT: This doesn't seem to matter, I have been starting them at different times and it still shows up as linked.
The 2 PCs I saw it work on are using IPs 192.168.1.3 and 192.168.1.4, as well as others I am now testing it with 4+, all are 192.168.1.1 through 192.168.1.6 .
On the main game screen where it asks you to Press Start and shows the coins, in the bottom right corner there's a red M, the number next to that M tells you how many cabs are linked.