Hi, this is probably a dumb question but I recently find out that my duty solenoids are far from good and I’m planing to replace them with three port mac valves but. My question is about the fittings, should I use 1/8 or 1/4 barb connectors? And will it make a difference?

 

I personally don't know but see if you can find your answer here: https://www.rx7club.com/3rd-generati...system-404243/

or search this forum for MAC valves. I know it has been discussed before.

 

Not a dumb question at all. Most people run 1/8” barbs on MAC valves since standard boost/vacuum lines are already small, and they work perfectly fine. Using 1/4” fittings usually won’t improve performance and just makes the setup bulkier. The MAC valve itself will make the biggest difference, so I’d stick with 1/8” unless your whole setup already uses larger hoses.