dude..you could use a small lawn mower battery...weighs like 8 pounds at the most...and a high volume fan is gonna be better than any car turbo...all hes gonna do with the car turbo is burn his exhaust valves...if you dont belive me go to any small engine shop and ask them what happens when you put any kind of back presure on a little 5hp brigs motor...there gonna tell you its gonna burn the hell out of the exhaust valve..and its a stupid idea to put a turbo on it.well atleast its stupid to do if you cant buy a turbo small enugh for the aplication..the turbos people are talking about on here are designed for atleast 100hp aplications..its not like you can go slaping a turbo on anything..it takes alot of time and thought on how to turbo somthing.. im no turbo expert but i sure do know that its not gonna work....so ide go with the fan..honestly...look on ebay at those electric super charger things..basicly its like a hair dryer fan...thats about what i would use on a brigs...