Best Vacuum line to tap for boost gauge?

[84ttype]

Like the title says I'm installing a VDO boost gauge and I just wanted to know which vacuum line I should tap for the most accurate reading?

 

[BRAD_PADGETT]

Mine is tapped into the vacuum line coming out of the fuel pressure regulator. Brad

 

[buickpower]

your best bet would be to get a direct boost signal from the manifold, it is the strongest signal and you don't have to tap any other lines. What you do is remove the pipe plug on the front lower part of the manifold, (close to the drivers side, behind the fuel pressure regulator). Then replace it with a brass fitting of the same size. You can get the fitting in small hardware kits for boost/vacuum gauges, they usually contain boost line as well, and are available just about anywhere that sells gauges. I know sunpro and vdo have little kits like that. The fitting threads into the manifold, and the outer end has a compression fitting that you slide the boost line into and tighten it down. It's really pretty simple.

 

[Bryan C.]

I used one of the lines that goes to the boost solenoid. One will work, the other will not.

 

[6SENSE]

The traditional "best" spot to get the signal would be at the passenger side rear of the intake. This is straight manifold pressure. Easy, just use a vac "T". Nice and clean spot to tap into that is out of the way and out of sight.

Dont think tapping into the vac line at the fp regulator would be very wise. Just seems to me that your taking a risk that you dont have to. The less chance of leakage there the less chance of blowing a headgasket due to lack of fp not going up with boost.


The spot at the front of the intake that buickpower mentioned should work too.

 

[Lee Thompson]

tap

I would not use the wastegate hoses, unless it is between the compressor housing and the restricted leg of the Y. After the restrictor (which is very small) it is bled by the wastegate solenoid and the reading has a very good chance of being off (low).
The perfect place is the unused port behind the FPR. This a direct input to the intake, same as the one on the back of intake, which is harder to service.