what's a good ratio to run at high rpm's? (standard ctsc) I have an aem af gauge and I notice at startup and idle it sometimes jumps past 16 to a point that doesn't display on the gauge like anywhere from 17-20. at higher rpm's I notice it goes from 12 then drops below 10 and to a point it can't be shown on the gauge somewhere in the range 8-10?. is that normal? should I be worried