Originally Posted by Mr PotatoHead
At what rpm are do they become helpful? Id think my 7300-7500 rpm deal would be under that but I know in my R5P7 build pile of parts is a belt drive.


Hard to say. I use a belt drive on any serious race engine even if the peak power is below 7000 rpm but not everyone thinks the same way. I'd say a belt drive is highly recommended for anything that is going to peak above 8000 rpm.