DIY Venturi system

[Grentarc]

Hi,
I am looking at doing a DIY WI setup, preferably as cheap as possible. This is why i am looking at a venturi setup, because i cannot justify the expense of an aquamist setup. Anyone got tips, schematics or anything that may help in this project?
main problem(s)- i can only use 91 RON unleaded, small budget, getting knock around 2-3 psi of boost because of 45?C ambient temps.

:? all help is appreciated.
thanks