[How to] Install an aftermarket boost gauge

Gary

Moderator
It'll read "actual pressure".
Note that "actual pressure" can be negative (a.k.a. vacuum) or positive (a.k.a. boost).
When you go from idle and start to open the throttle, the gauge should move from 17-19 in.Hg of vacuum and goes to "0" vacuum (which is "0" boost).
And if you still keep pushing your right foot on the pedal :D , the needle will keep going from "0" boost to 1 psi, 2 psi, 3 psi ..... Then when you lift your right foot, the needle will move back to vacuum.
watch this clip:
http://video.google.com/videoplay?docid ... 8322914594
 

gt4tified

New member
Yeah my gauge does that but how do I know how much boost I'm making....is it just the max reading on the boost/positive side? I thought it would be a kick in the needle or something... :doh:
 

Gary

Moderator
What gauge are you using?
It's a little bit high (vacuum)
But I know people that has the same reading as yours but everything seems OK.
 

Gary

Moderator
I wouldn't say that 22-23 is too high. Gauge can be error too.
But normally, high vacuum reading may be caused by advanced timing.
 

Gary

Moderator
Rubber hose and 5/8" brass adapter from ACE hardware.
Nylon tubing and connectors supplied with the gauge.
You can get them from Autozone too.
 

snakeeater

New member
tw2":1grl9sh4 said:
Yes you can T it off for your BOV vacuum.
Gary":1grl9sh4 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.


Could I T It before That white filter thing or one the line next to it?? Would I get as accurate readings compared to if i Used the "proper" port??
 

Gary

Moderator
snakeeater":3tyzcrtv said:
Could I T It before That white filter thing or one the line next to it?? Would I get as accurate readings compared to if i Used the "proper" port??
Yes, you will get the same reading.
That plastic thingy is a "jet" or one way valve.
If you connect the gauge to the line before it, you will read both vacuum and boost correctly.
 

SleepingTurbo

New member
is there a way to route the vaccuum lines into the radio space? my car doesnt have a radio, and i was gonna use that space for my gauges.
 

Tarmac_St165

New member
On the 165 there's 2 fittings in the intake I wasn't sure witch one to use. One looks like it went to the brake booster? So I used the other one, I just pulled the existing line off and connecting my new hose. Should I block off the old hose will that give me a vaccume leak if I leave it there? I have it like this for a few days it seems fine, My gauge reads 15 vac when its cold and about 19 or 20 when warmed up.
 

Gary

Moderator
SleepingTurbo":j0b2lrss said:
is there a way to route the vaccuum lines into the radio space? my car doesnt have a radio, and i was gonna use that space for my gauges.
Sure, if you have the nylon tube that is long enough.
 

Gary

Moderator
Tarmac_St165":yc8v7a1k said:
On the 165 there's 2 fittings in the intake I wasn't sure witch one to use. One looks like it went to the brake booster? So I used the other one, I just pulled the existing line off and connecting my new hose. Should I block off the old hose will that give me a vaccume leak if I leave it there? I have it like this for a few days it seems fine, My gauge reads 15 vac when its cold and about 19 or 20 when warmed up.
I would use a T-fitting.
 
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