Let’s talk about a well worn topic: Boost gauge tap location. This is my second Evo. My first Evo had a Defi gauge installed here:




Well, I didn’t want to tap there, since that’s the rising rate fuel pressure line. I tapped my last car there and the line came off due to not using a tight enough zip tie. The result? The line blew off in full boost at WOT, leaned out the car substantially, and resulted in a hairline crack on the face of my #1 piston. There was zero damage to the rest of the engine, as we caught it early and replaced the piston with OEM Mitsu 63TE8 (uniform) pistons. Fortunately, I caught it in a high rpm miss that showed up as a wet plug. After a borescope, head pull, and tons of work labor, that car was as good as new.

That’s old news. Here’s the new news: I don’t want to tap there again with my IX! Mitsubishi taps the factory gauge at the driver’s side at the manifold at a line near the back of the valve cover. Their gauge works perfectly.

However, when I try to tap my Omori gauge there, it gets ridiculously shaky. Why can the OE gauge take that as a reference point but the Omori can’t? I don’t want to tap my boost gauge at the rising pressure regulator pictured above. I don’t care how stable it is, it is not a good place to tap a gauge for safety reasons IMO.

Have any of you tapped aftermarket Omori or Defi gauges elsewhere with good results and no shakiness? Thanks for any ideas. We use the front boost reference on the dyno with great results, but it doesn’t work well for stability on a gauge.

 

I followed some tutorials and tapped mine off the area shown in red. No fluttering or shakiness. Hope that helps.

 

Ummm, the one that the OP circled is not the fuel pressure regulator vac line, the one the second poster circled is. I used that line, but I used a zip tie tensioner to pull the ties tight. It looks like a gun almost that you put around the tie and squeeze, and it tightens it as much as is physically possible.

 

no my factory boost gauge was tap in to the same spot in the picture. the factory one came with t fitting and 3 hose clamps that's why it neve blow off.

 

Update- Retapped to another place, shaking continued. Retapped again to the circled yellow spot and zip tied the crap out of the line, used new line. Shaking still continues.

I think I have a defective gauge.

 

what kind of gauge is it?

 

thats where I tapped my gauge vacuum in the picture with the yellow circle. My gauge is pretty good believeable accuracy. It noticed my boost controller and holds boost at 18/19 psi.

 

you could simply use the same source that the BOV uses coming off the center of the manifold...

 

Ok This is Very simple, its like 1+1=2. ALWAYS get your boost gauge reading from the line that goes to the regulator, BUT on the manifold side of the selonoid NOT on the side that goes to the Regulator.

 

pull the line circled in yellow completley off...and take the end of the one circled in red that goes into the back of the manifold and connect it to to where the yellow on went into the manifold....just keep those other 2 ports open...thats how i ran mine and several other evos in the arera.....

 

A restrictor in the T fitting will reduce/get rid of the shaky reading. That is how the T's supplied with Greddy and Defi gauges are done.

 

Stewart Warner Gauges that I got also came with a restrictor built into the T fitting.

My recommended location for getting boost pressure was in the Diverter Valve line which runs over the top of the cam cover.

 

steward werner tapped off the reg. no probs, all other sources gave me a shakey needle.. wow spelling sucks today..

 

i would contact 42draftdesigns.com and buy a T-fitting with the restrictor in it. i had the same problem untill i installed their T-fitting

 

So for clarification for everybody, you are refering to the line/source that is circled yelloow in the above pic correct?