Michael, a regular Stinger is very similar in brightness to a Surefire 8X. That may not be an accident in the same way that a Streamlight Scorpion is very similar to the Surefire 6P. The Ultra Stinger is very bright for its cost, brighter than the Surefire 9N, but not as handy. If you want cubic lumens, then you get a 10x Dominator, or maybe the Beast, when they're available, or ..... It never ends, does it.
Anyhow, in spite of some formulas bandied about, there is NO formula relating candlepower to lumens. They're different animals only somewhat related. Candlepower is the density of light at the brightest spot in the beam and therefore can be changed by altering the focus of your Stinger (or Maglite, etc). Lumens measures the total light output of the flashlight and will NOT change as you focus the light. You can verify this on the Surefire web site (I think) or in their monster catalog. Hope this makes it all clear.
Steve