According to their website in the first paragraph it says
Street Runner and ThermoMaster chips both contain Hypertech Power Tuning programs. ThermoMasters contain special programming that allows the use of a 160-degree or 180-degree thermostat. If you can't or don't want to change the thermostat, then use the Street Runner.
And also earlier my engine was running at like 230 and i added some coolant and now its running lower and the problem seems to be fixed, but when ever it goes above 215 or so im guessing it loses power, bad fans? whats the deal?