intake manifold - new boost/vac sources

[Calan]

Has anyone removed the machining plugs from the intake and used them as vac/boost sources? They are on each end of the main runner, circled in red below.

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I'm mounting a PCV catch can off the end of the manifold where the coil pack used to be, and that end plug would be an ideal spot for my PCV vac line. And the one at the TB end would be ideal for my BOV source. This would eliminate lines running up from the center and cluttering up my fuel rail.

On a related note, which of the TB ports are post-throttle plate? I have two boost sensors and my AFPR... if I could run all 3 directly off the TB that would also clean things up.

Opinions?

 

[snowborder714]

From the link forums:

I think that passage is related to EGR operation. I don't think it's a good location for a MAP sensor.

Dave

Also, look up inside the runners and see how small those holes are. Eric and I just don't like those two spots for anything.


P is the only port. I would maybe do that for those 3 sensors, but I would probably find another way if possible.

 

[Calan]

Hmmm...

I would think the end ports would work, at least for the PCV. If you'll notice, the factory PCV port is a direct shot down into that runner. And my EGR is blocked off.

Maybe I'll just drill and tap some new sources on the back side of the mani for the boost sensors, or use some 90* fittings and find a better route for those.

 

[Rob10_99]

Those holes are 1/8th inch or so, very small and my be plugged from PCV recircing over the years.
For a manifold pressure that will work yes. But its better if your straight behind the TB.

 

[Calan]

Those holes are 1/8th inch or so, very small and my be plugged from PCV recircing over the years.
For a manifold pressure that will work yes. But its better if your straight behind the TB.

You mean the holes behind the plugs are 1/8"?

What if I drilled them out to be larger and tapped them to something like 1/4 NPT for the PCV return? The boost sensors and BOV lines are only 3/16" or so anyway, so I think I could make those work pretty easily.

 

[Rob10_99]

No I mean inside the runners into the ports, the holes are fairly small.

 

[kenamond]

Are there ill-effects to be concerned about with tapping into one runner vs. the plenum? The pulses from one runner might matter in some obscure way.