Hey guys, this question might sound kinda stupid but it just popped into my head today and am interested to find an answer. if you were to turbocharge an engine (or supercharge for that matter) that didnt use to have boost, would it affect vaccum in any way? for example, im sure it would be normal at idle or very low boost conditions, but suppose you had upwards of 20 psi...i was just thinking, would all that pressure cause less or even negative vaccum? if so, that could really screw things up like tranny shifting, or in some cases vaccum advance. anyway, thanks in advance for any info you guys have.

 

Yes, it does screw things up and the turbocharging book I have
shows you how to install, among other things, check valves
to manage boost conditions.