ok so heres a question for yall that ive been wondering about for a while now but never really consiously wanted to ask. how does a boost guage measure your boost? and what is the boost measured in?

 

it hooks to the intake manifold, and measures what is normally vacuum on an NA motor. it basically measures the pressure inside the mani in comparison with atmospheric pressure. most that you buy in the US will measure in PSI, some measure in BAR as well, which one bar is one atmoshphere, or 14.7 psi.

 

Hooking to a HOnda you must be careful, alot of time people TEE into an exsisiting vacuum line coming of the IM which is fine but Honda uses some check valves in some of their vacuum lines and you have to make sure the TEE is seeing true IM pressure and also dont hook it to the TB, that reading will be no good.

 

im still kinda confused. so does it display the difference between atmospheric pressure and the intake manifold pressure?

 

atmospheric pressure is 14.7 psi, so at 0 lbs of boost it is 14.7 psi in the manifold and then as the boost climbs that is posotive pressure in the intake manifold. The air in the IM is actually compressed.

 

ok well i knew that but i did some reading up on them today and get it now...thx