if im using a vacuum manifold should i plug the vacuum nipple on the turbo compressor? or should i just leave it open?

 

yes plug it

 

leaving it open would be your best option, as that would bleed off the boost that your turbo will produce, this will result in the greatest amount of horsepower possible with any sized turbocharger! this will also produce alot of extra airflow under ur hood to keep everything under there cooler. o, and by the way, i'm kidding.

 

uh if u dont plug it it will leak boost

 

that is a boost source and never sees vacuum.....it is supposed ot go to the bottom port of the wastegate