Boost gauge install questions

So im looking to install a Defi Racer boost gauge pornably to the steering column.

Looked for bg install threads but only caMe across earlier generation installs.

Where do you tap in or install the t-fitting for boost pressure on a f25 motor?

Is there a closer ir easier option other than the bpv that is way up front of the motor?

Also, best and easiest location of grommet to engine bay access from interior.

Any pictures would help as a thread i followed had factory boost tap in a diagram that i couldnt figure out by the picture as there was no written imstruction on the location of this vacuum line.

Thanks for any help.

I put a tee fitting between the MAP sensor and the inline filter thing (see pic here, BYO racecar blue vacuum line), although there's probably a couple of good options on the rear of the manifold as well. I went with that location because a) you don't have to pull the intercooler to get at it, and b) it doesn't share a pressure signal with anything other than another sensor. The sensor for my SPT gauge died because it was teed into the PCV line and placed lower than that line, so it filled up with water, which is probably why I went downstream of the filter like I did.

As far as a grommet, I don't think I got a picture of it when I did it, but there's a good-sized passthrough on the driver's side firewall that pokes through inside the pedal box that works well. It was a snug fit, but I was able to tuck a small connector through there next to the existing wiring. From there, I went up the left-hand side of the dash toward the fuse panel (add-a-fuse taps in F/B 10 (currently 7.5A) for battery power, F/B 27 (currently empty) for ignition), and wrapped around the top of the dash to the "factory" install location above the gauge cluster.

Edit: thought I posted this somewhere, but I guess I didn't. The colors will likely be different for your install, but the functionality will be the same. I 3D printed a little connector to join the engine bay side and the cabin side just because I could, but you could just as easily use butt splice connectors for that.

Thanks for the response.

Does anyone have actual pictures of where the MAP Sensor is located in the engine bay for me to tee into?

It would help me visually when I look under the hood as most threads are just in black in white outlines or not too descriptive.

If not, a picture and location of another vacuum line I can tap into for the boost gauge.

Im hoping I can knock this install out this weekend since its been bad weather lately and Im getting rain in my garage due to flash flood rainfall.

Thanks!

I put a tee fitting between the MAP sensor and the inline filter thing (see pic here, BYO racecar blue vacuum line), although there's probably a couple of good options on the rear of the manifold as well. I went with that location because a) you don't have to pull the intercooler to get at it, and b) it doesn't share a pressure signal with anything other than another sensor. The sensor for my SPT gauge died because it was teed into the PCV line and placed lower than that line, so it filled up with water, which is probably why I went downstream of the filter like I did.

 

As far as a grommet, I don't think I got a picture of it when I did it, but there's a good-sized passthrough on the driver's side firewall that pokes through inside the pedal box that works well. It was a snug fit, but I was able to tuck a small connector through there next to the existing wiring. From there, I went up the left-hand side of the dash toward the fuse panel (add-a-fuse taps in F/B 10 (currently 7.5A) for battery power, F/B 27 (currently empty) for ignition), and wrapped around the top of the dash to the "factory" install location above the gauge cluster.

 

Edit: thought I posted this somewhere, but I guess I didn't. The colors will likely be different for your install, but the functionality will be the same. I 3D printed a little connector to join the engine bay side and the cabin side just because I could, but you could just as easily use butt splice connectors for that.

https://www.subarupartsdeal.com/resources/installation/SPD/18_063767-H501SAJ200.pdf

that's the installation instructions for the SPT boost gauge from Subaru. not sure how much that will help, but should give you an idea

I don't have a direct picture here, but mine is tee'd off of the line that goes to the BOV, if you follow the hose up through the engine bay, i tee'd it right there for ease of reaching it.

I bought the car modified so I'm not completely confident you'll have a similar line, but what is in my engine bay looked pretty OEM.

As far as the location of the MAP sensor, that's what's connected to that plug directly below the right-hand side of the rectangle in Aphex28's picture above. I tee'd in between the MAP sensor and the filter, which is the round foamy thing straight to the left of that green plug on the alternator. Pretty sure I posted a picture of my setup somewhere, I'll link to that if I can find it.

edit: here you go: https://legacygt.com/forums/showpost.php?p=5445107&postcount=22541

The plug with the orange cable seals is for the MAP sensor, the round black thing to the left of it (and the triangular 3-pin connector) is the pressure transducer for my boost gauge.

Great!!

Thanks everyone for all the info!!

As far as the location of the MAP sensor, that's what's connected to that plug directly below the right-hand side of the rectangle in Aphex28's picture above. I tee'd in between the MAP sensor and the filter, which is the round foamy thing straight to the left of that green plug on the alternator. Pretty sure I posted a picture of my setup somewhere, I'll link to that if I can find it.

 

edit: here you go: https://legacygt.com/forums/showpost.php?p=5445107&postcount=22541

The plug with the orange cable seals is for the MAP sensor, the round black thing to the left of it (and the triangular 3-pin connector) is the pressure transducer for my boost gauge.