Have a gas grill(indoor resteraunt) that is not hot enough
Star is a comm'l manufacturer. If you are using it in a comm'l setting (ie. restaurant), then it may be set for the wrong gas type (it may be set for natural while you are providing propane). Is it lava rock or radiant? If your regulator is for the correct gas type and the broiler is for the correct gas type, call your gas servicman, he could, possibly, drill out the orifices, providing more gas to the burners, thus making them hotter (DO NOT TRY TO DO THIS YOURSELF!). The economy Star broilers have never been real hot (I am a comm'l restaurant equipment dealer) but your gas man could make it more acceptable. Call your professional, licensed gas serviceman to make things a bit better.