If you have a 2ltr enguine and 4 cylinders running at 2000rpm taking a 2ltr per min hho unit connected! Working this out roughly it seems a very low imput?? Here is my reasoning! 1)Piston size: .5ltr per piston 2)Firing speed:500 times per min at 2000rpm 3)HHO output:2ltrs per min (devided by 4 pistons) In my rough calculations .5ltrs(air drawn into piston before ignition)x 500 times a minute(times a 4stroke piston fires at 2000rpm)=250ltrs per minute per piston! Now devide your 2ltrs hho by 4(amount of pistons sucking air and hho)=.5ltrs per piston per minute??? Now if your one piston sucks 250 ltrs per minute of air and only .5ltrs is hho thats roughly 1/500 ratio and that equates to .001ltrs hho-.5ltrs air per piston per explosion(firing stroke) so what I want to know is do we need to consider a much higer ratio to make more effect?????