Those gauges are nothing more than "go/no go" gauges, but you definately might have a serious problem.
The reason I say that is that the ALWAYS go full green under WOT. If yours is not showing this, you may have a "no go" situation.
Get that sucker on a wide band and find out what's going on.
Also, with your HP, I'd look at getting a true wideband gauge .... the dynojet one is a beautiful piece.