[How to] Install an aftermarket boost gauge

Gary

Moderator
What you need:
1) A mechanical boost gauge.
I'm using an Auto Meter® Ultra-Lite 2-1/16" (# 4301) comes with 6ft nylon tubing and fittings.
2) 5/16" (inner diameter) rubber tube
(at least 4-inch long, mine is 1 ft.)
3) 2 Hose clamps for the rubber tube above.
4) Adapter (from any hard wear store) to connect the rubber tube
to the NPT fitting (provided with the gauge)
5) Teflon sealing tape or sealing compound.

Schematic:
bginstallationpt2.jpg


What to do:
1) Locate the vacuum/boost source behind the throttle body.
14jf1.jpg

24mv.jpg


2) Remove the rubber cap. Keep it some place safe.
You might need it in the future.
32mm.jpg


3) Connect the rubber tube. Use the clamp to secure it.
40zu.jpg

58vn.jpg


4) Connect the other end of the rubber tube to the nylon tubing
(provided with the gauge). Always use Teflon sealing tape.
63pe.jpg


5) Route the nylon tube trough the fire wall.
I route it through the driver side wheel well.
75iu.jpg


6) Connect the nylon tube to the meter following the gauge instruction.
Start the engine. Check for leak. Gauge should read about 17-21 in.Hg at idle.
86wq.jpg


7) Connect the gauge light to the power source. I parallel it to the ash tray bulb.
The light will turn on with other interior lights. It can also be dimmed with the dimmer.
96jg.jpg


8 ) Drive the car and check the boost. Now, you will realize how slow the stock boost gauge is!
Stock boost is around 7-11 psi.

Disclaimer: Do it at your own risk. I'm not responsible for any damages caused by following this instruction.
It is your responsibility to make sure that materials are fire proof and
can withstand heat in the engine compartment.
Always follow manufacturer's instructions.
 
Quick question... I heard from other sources as well that you can route it through the wheel well. Any disadvantages to this setup than via the firewall, and how exactly would it be done?
 

toayoztan

Moderator
AlltracAvenger":20e7rj4j said:
Quick question... I heard from other sources as well that you can route it through the wheel well. Any disadvantages to this setup than via the firewall, and how exactly would it be done?

It's just easier to go through the firewall than the wheel well.

Bryan
 

RIalltrac

Active member
AlltracAvenger":3alvybm2 said:
Quick question... I heard from other sources as well that you can route it through the wheel well. Any disadvantages to this setup than via the firewall, and how exactly would it be done?

You need to remove the liner on the inside of the wheel well, then you'll see the boots that wiring goes through. You could use those same boots to get the vacuum source in/out. I did the firewall method, but plan on changing it to the wheel well option, just cleaner overall imo.
 

QIK_GT4

New member
ok i installed my boost gauge just the other day and why the hell is it reading at 25 - 30 in.hg?

look i got a pic..
boostgauge.jpg


is my car stuffed or could gauge be inaccurate?
 

toayoztan

Moderator
Aus_GT4":139dd20r said:
Is this essentially the same write up for an st185?

The car used in the pictures is an ST185. In any case, this write up can be used for both the 165 and 185.

Bryan
 

Gary

Moderator
For people without an empty port, you can just use a "T" on any vacuum line from the intake manifold.
 

tw2

New member
Yes you can T it off for your BOV vacuum.
Gary":38fnbf5a said:
For people without an empty port, you can just use a "T" on any vacuum line from the intake manifold.
Not that this is important at all but I recently found that my boost gauge had been T'd into the line going to the I think AC idle up valve. This line had a filter or check valve or something in it which affected vacuum reading and sometimes boost. I changed it to the way described here.
filterthing.jpg

This thing here from
Vacuumline.jpg

This port here. You can see all the other ports on the manifold in this picture. There is a largish one under the last "hole" on the TVIS.
 

gt4tified

New member
Correct me if I'm wrong but with this setup above, boost would be indicated by an increase in vaccum? If I just wanted it to read boost alone, how would I hook it up...someone told me to 'T' the hose between the wastegate and the intake side of the turbo.
 

Gary

Moderator
gt4tified":bbu7saf1 said:
Correct me if I'm wrong but with this setup above, boost would be indicated by an increase in vaccum? If I just wanted it to read boost alone, how would I hook it up...someone told me to 'T' the hose between the wastegate and the intake side of the turbo.
It depends on your gauge. Most boost gauges can also read vacuum (which is very infomative).
You can T that hose but it will only read pressure before the IC, not the real reading of air pressure entering the cylinders.
And 99.999999999% of the time, we don't refer to the boost reading from the that location.
 

gt4tified

New member
99.999999999999% :lol: Gary you're a trip!

Anyway, what u say makes sense. Tell me though, with the boost gauge that reads both vaccum and boost (me gots one of doze) connected the way you described to the vaccum port on the rear of the manifold, under boost would the gauge read an increase or drop in vaccum?
 
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