I previously had my map sensor signal referenced off the brake booster line.

I noticed however, that under light boost- like 3psi, the signal oscillates like crazy and freaks out. I can see my needle flapping on my boost gauge. Braineack once wrote that particular port is turbulent and my boost gauge may be confirming it.

I want my MAP signal to be stable as hell. I have a bunch of stock ports capped off on my intake. They were originally used for emissions. I have no clue why the hell Mazda placed them where they are. I mean, a few of the ports were actually connected to other locations on the IM. One had a check valve between ports. What the ****?

Is the consensus that it would be safe to use one of those stock ports?

Or should I use my hole saw and make a fresh 1 inch port for my signal? J/K I mean a 1/4" port.

 

I use the ones by the TB. So long as it's post TB and not on a runner, you'll be fine.

 

I use the one at the back of the mani. Dead reliable and accurate signal.

 

i use the port that was for the pcv on the valve cover into a vac block

if i were doing it over i would invest in an AEM sensor and tap it right into the intake manifold plenum.


i found that the ports on top of the 1.6 intake manifold that were meant for the purge solinoid or something didnt read boost on my mechanical guage... so be careful

 

The big *** port for the brake booster?

 

No, the one under it.



Look at the line teed off at the back and connected to the port underneath the big brake booster one.

That's the one

 

Oh ok that one. That is something like 1/8" ID right?