I would think that a KB would bennefit from a 2 stage if the 2nd stage came on with the increase of RPM.King Torq said:if boost is on you like a light switch, say a fast spooling turbo, or a KB, than stange 1 would be fairly optimum. However, if you build boost with rpm (centrifical vortech) than the stage two would allow you to tune the injection sooner in the mix and richer as you build.
I don't know if its a hp point where one would switch from stage one to two, but more a tunability point. Say you had stage one, just off or on with a relay, then your pretty much just putting it all in at say, 6psi,.. then you may be a touch over enriched at 6psi, and not quite fully enriched at 9psi. Where as with the ramp up delivery of stage two, you can come on earlier with less delivery, and not worry about being too rich or flooding down low, and still get the nice full enrichment up top.