factory rb26 boost solenoid open to atmo

[syd_gtr]

on a minty nur 34 with a power fc his factory boost solenoid (the oem one fixed to strut tower) was open at the pointy end to atmosphere. No tube. No aftermarket boost controller.

mine, whether electrically connected or disconnected sucks a pulsing vacuum through that end at idle. It seems to make a slight difference to idle (open to atmosphere vs not)

is a factory boost sensor supposed to leak vacuum? is it normal to have it open to air?

[BK]

Factory RB26 boost control solenoid is normally closed mate, so it's not leaking anything to atmosphere at idle. Standard setup opens when activated and vents in front of turbos - completely different to a Mac valve setup.

 

[syd_gtr]

thats right.

however if you pull the front hose off at idle at least mine is sucking a vacuum like in rhythm. I can feel it. so is it broken? (it is new). It doesnt screw up idle like removing the other hose to it does though.

and why would this beautiful nur pfc have it open to atmo? maybe there was a hidden boost controller and this was not connected? would be news to the owner though.

Edited April 1, 2021 by syd_gtr

[GTSBoy]

Why not just look at the diagrams and put it back the way it is supposed to be instead of worrying about it?

I swear, the things that cause threads in this place.

[syd_gtr]

a) it isn't my car with the disconnected hose, I was curious if this was common.

b) I like to know how things work in detail. stock, the solenoid is normally closed, is it also slightly leaky?

perhaps it is better not to create any topics at all on sau - since everything has been asked before even if it can be difficult to find the exact reply, and of course there is a manual to refer to if one doesnt want to know the whys of something.

[joshuaho96]

Skip to 6:00, it explains how the OEM boost control works. The "pointy end" I assume is the outlet that normally goes to atmosphere. In an RB26 it vents to the rear turbo closest to the firewall before the compressor, but after the MAF. The RB26 OEM boost control is a fixed duty cycle output on the solenoid, it doesn't seem to have any form of closed loop control or special intelligence. I've unplugged the wires to the solenoid on my car for now to run wastegate boost and there's not even a CEL if that tells you anything.

As for why someone would do such a thing frankly I have no idea. It's entirely possible it had an aftermarket boost controller at some point and someone ripped it out prior to sale with no real intention to reverse the modification in a clean way.