Initial boost gauge Q's

[BSOD2600]

I finally got around to getting myself a boost gauge and picked up an Autometer gauge (3301) and mounting cup (2204). First problem I ran into was it didn't come with a T fitting or any way to connect up to the vacuum line. After running all around town (napa, schucks, and finally novaks), I found a solution. Took a umm, 5/8" hose and inserted the 1/8" plastic tube into that.



The fitting seems snug enough, but is that really the best way to make the connection?

After getting the tubing zip tied down in the engine bay and routed up through the dash, I duct taped the pod to the steering wheel and took it for a spin. I haven't put teflon tape around the connections yet. After a quick drive around town, I saw the vacuum typically range from 10-20 hg. WOT up an on-ramp I saw 8-9 psi. I thought the stock boost was 7 psi -- does that mean this gauge is off by ~2 psi?

Lastly, seems that even slight deceleration in gear causes the boost to get dumped; is that right?

[rad rex]

I did my install the same way, looks right to me. make sure you have the connection snug at the back of the gauge or it won't give accurate boost readings. 9PSI is the highest stock boost you will see, I have no idea what the stock vac readings should be, but do a search for that specific topic and you should find a few threads.

[Imprezive]

I thin you will be alright, you might smear a bit of silicone gasket maker around it then shove it back inside the tube to be safe.

Vacuum will range anywhere from 15 in/hg to around 20in/hg

[92ss satinsvoice]

when i let off the throttle i get about 22 or 23 vacume. its good

[Legacy777]

That should do you fine. Intake vacuum at idle with a/c off should be 19.89 in/hg

[farfrumwork]

19.89 inHg at or near sea level.

We get about 14 inHg at idle up here 1 mile over sea level. Just a quick fact for the day....


continue.

-Chad

[BSOD2600]

19.89 inHg at or near sea level.

We get about 14 inHg at idle up here 1 mile over sea level. Just a quick fact for the day....

Ah good.. was just about to say that after a few days of driving around, seems my average is ~15 Hg. Elevation is ~4100 ft here.

Now that I finally have a gauge, I'm noticing a few things. Is the boost suppose to bleed off, during some partial throttle? Basically lets say I accelerate so I've got some boost, then slightly left off the throttle. I can hear/see the boost get dumped. Then if I partially accelerate, I can hear the boost still being released. That normal?

Probably dumb question, but if the car normally is around 15 inHg and the stock boost level is ~7 psi, doesn't that mean the turbo is actually producing ~14 psi (15inHg = 7 psi) ?

[555BCTurbo]

Stock boost is 8.7 psi


the inHg is inches of mercury, which is how vacuum is measured...my car pulls 19 at idle...and around 14 on the freeway...

[Legacy777]

Yes, boost should bleed off a little at part throttle.