Jun 19, 2019

Where do I tap my RB26 for a Boost Sensor , or Boost Gauge?

By Sean Morris June 19, 2019 boost source, Featured, RB26, RB26DETT, technical, vacuum

The sensor on the left is a factory Nissan Skyline boost sensor. The one on the right is an aftermarket sensor

I have gotten this question a few times. Seems like there are some special strawberries out there, that need their hand held, and shown exactly how something should be done. Step by step, no thought process, or reasoning required. So here you go.

The factory boost sensor in a Nissan Skyline GT-R only drives the gauge on the dash. That is it. It is not an input in the ECU for engine control. The small line on it often comes off the balance tube as it gets hardened with heat over time. They are often split. It is a tough line to see on the car, but you can feel it fairly easily. The balance tube is the cast aluminum piece under the plastic wiring harness.

This tube supplies the OEM boost gauge. If you want a signal pick it up here. This is the top of the balance tube. This is the rear part of the balance tube. It is upside down to how it is mounted in the car.

OEM fuel pressure regulator. Line has been tapped to add a boost gauge. DO NOT DO THIS

Do not tap off the fuel pressure regulator line. Sure its easy to get to. Sure the boost controller manual says to tap there, DON'T. Every extra T you add, adds failure points in a very critical system. More info

Apex'i says to tap into the individual ports to supply a source to their boost sensors for a Power FC D-Jetro. We have tried it. It doesn't provide a very stable or consistent source, as you aren't getting a summed value, rather just a few cylinders. Despite what the instructions say, connecting them to the rear of the balance tube, seems to make tuning the Power FC D-Jetro much easier.