By the term "heat trap", do you mean the large gray plastic engine cover held on by the oil fill cap? Is it better to leave that off? It seems to serve no purpose. What is it'* purpose?
It'* intended to clean up the look of the engine bay. It does trap heat, which on a SC motor can be problematic if your trying to squeeze extra ponies from it with increased boost. It'* up to you if you want to keep it on or not.