I think I know what Burritos is talking about. It's an old rule of thumb-type thing that if you are taking off into suspected windshear, you bump your speeds up to the max speed for the runway restriction weight. So lets say your airplane weights 200,000 lbs, and your runway restriction/climb restriction is 300,000 lbs, you use speeds for 300,000 lbs (or your max takeoff weight if it's lower). You also use the maximum thrust setting available (no thrust reduction). Then you'll rotate a little farther down the runway, at a higher speed. Now, you also can climb at a lower deck angle should obstacle clearance allow. This extra speed above Vs will provide you with some potential energy, which can be transfered into kinetic energy should you encounter windshear.
Can't say I follow this rule myself, but I have read and hear about this from some older pilots. Makes some sense I'd say. If you are going to experience windshear, would you rather have a 1.3 margin above Vs, or a 1.5+ margin above Vs?
Check out the windshear section of "Fly the Wing" by Jim Webb.
