ls1290

iTrader: (20)

How important is the location of an outlet to measure/accure vacuum off of the intake manifold; say the front verses the rear? I am thinking of using the port for the PCV system to install a boost gauge. Will this give the same measurement as tapping into the brake booster line?

Thanks,
Keith

stevieturbo

Yes. But make sure you either restrict the line, or use very small diam hose. Otherwise you will get fluctuating readings/shaky needle

This applies regardless of where you take the reading from on the inlet manifold.

ls1290

iTrader: (20)

How size of a hose line would be good? I was thinking of using -4an telfon line to go from the PCV port to the rear of the manifold; I guess that is about 18".

Keith

stevieturbo

A hole about 0.010" to 0.020" would be small enough to ensure a smooth reading with no irregular needle shaking.
Simple rubber hose would do. 3/16" or about 3-4mm ID. Depends on size of fittings you are pushing the pipe onto.