Ok i have a total noob question. what is a boost guage i no people have them with a BOV. can you use them with a D-BOV? what is boost any ways. I always here people talk about PSI whats that about? If some one could please educate me on this that would be great. Thanks!

 

If this is a serious question here are your answers.
BOV or blow off valve is the same as the diverter valve that comes stock on your audi, the only difference is the bov purges the air to atmosphere instead of re-directing it back into the intake.
PSI or pounds per square inch is the unit of measure that we use to measure boost output of the turbo charger. When the turbo charger spools up it developes positive pressure which is measured in PSI, PSI is what is on your boost gauge, you're just measuring how much pressure the turbo is developing, a stock 1.8T for example should put out about 9 psi of boost.
To attach a boost gauge to a engine all you have to do is locate a vaccum line and hook it up to the guage, it will read vaccum until the turbo developes pressure then it will go above vaccum to boost.