Good idea? Using the EGR hole for mounting boost sensor?
 

I got to thinking about this last night... rather than drill and tap a hole in the intake manifold for a boost sensor, or try to figure out where to mount one elsewhere underhood, why not drill and tap the EGR blockoff plate and use that? BTW: this is for a electric sender for a boost gauge, not an ECU.

Someone explain to me why this is a bad idea, seems too obvious not to try.

why would you drill and/or tap anything at all on the mani? there are a couple ports not doing anything as is, and you can also tee into a bunch of other ports on the mani as well.

I hadn't noticed any extra 1/8" NPT threaded holes in the manifold when I looked last. :giggle:

Sure I could tube/tee/clamp it into something else, like the PCV or the brake booster line, but that's another tee and looks like crap. The goal would be simplicity. Why run a bunch of extra tubes and tees when I can just thread into a hole and run 2 wires? I'm just wondering if the EGR port would be a representative source of what's going on inside the manifold.

Ah, so you're trying to bold the map directly to the mani. (guess I didn't understand that in OP).

Then I don't see any issues with that, esp since you're just running the signal to a boost gauge and not an EMS map sensor

Yeah, I could see how that was not clear, added "EGR" to "blockoff plate" in OP.

Plus, I'd prefer not to drill & tap this squaretop and eff it up. Everything I touch seems to be full of fail recently.

You're going to use the blockoff plate for the EGR valve, not for the EGR tube, right?

--Ian

This is important :P The EGR tube doesn't actually connect to the manifold anywhere - it just loops into one of the holes on the EGR valve. If you tap a block-off plate, make sure you're tapping the right hole.

I tap the mani so hard i leave a gaping hole in it.

https://www.miataturbo.net/attachmen...ine=1332287816

Yup that's how to do it.

Just tap the bitch anwyerh

You guys got it. I figure it would be good enough for a gauge. And yes, sticking it in the right hole is key.:giggle: