mydejavooo

I just bought a used set of Autometer gauges, and in the set is a vacuum gauge. The gauges came out of a race Corvette. My question.....as dumb as it may be........why do you need one of those? I can see it on a car that has a turbo, but mine is not a boost gauge. It looks "cool", I guess.....but really, what purpose does it have?? Stumped.





Deja

MakoShark72

Sure can be a heck of a diagnostic tool...

Check out this website, and scroll down a bit.

http://www.secondchancegarage.com/public/186.cfm

I never knew a vacuum gauge could be so useful!

snoopykissedlucy

1) no one knows how to spell vacuum
2) you can adjust your carb with it
3) you can save gas by changing your driving habits with it
4) you can watch the needle go to zero when you floor it
5) you can be proud when you idle at 600 yet have a steady needle
6) all vacuum gauges suck....har har har!

eagle275

noonie

It easily disproves the myth that S Florida is flat.

MY old BMW had one disguised as an economy meter.
If you get used to driving with one, you can substantially change your habits to increase mpg.
I originally ran with one when playing around with different power valves for a Holley.
Just always kept it draped over the steering column by the hose.

Besides engine load, it can quickly tell you if something drastic happened in the engine.
Great diagnostic tool, mostly at idle.
I would keep it.

Ganey

It was probably put in to replace the clock.
I have a Corvette oil temp. in place of the clock.

wcsinx

*ding* *ding* *ding*

We have a winner! Before the days of computer controlled engines, it was not uncommon to see vacuum gauges rebadged as "economy meters". Keep the needle in the green!

And yes, it sure does make tuning a carb easier!

noonie

It wasn't that old. It was computer controled FI

682XLR8

I have a small vacuum gauge made by US Gage I scrounged up at work I use for carb tuning, put a hose barb on the end and attach it to the base of the carb when doing carb adjustments it can also help find other problems as the site Mako posted points out
Also helpful when trying to isolate leaks in the vacuum system especially with all the plumbing these early Vette have

70ZZ3 96LT4

Ever since I learned how to adjust a carbruetor in the 60's using a vacuum guage I installed one in my bought new 70 coupe. It has helped in realizing I needed a new power valve in my Holley or having a vacuum loss. Have it mounted in a single guage holder.

larryg3

What a great link!!! and to think my vacuum gage is just siting in the tool chest collecting dust.
Thanks for sharing. Now i have a new favorite diagnostic tool.

CCrane65

'65 Impala SS's came with them in the dash off to the right of the driver instead of a tach.

cc

NHRA686

If it was a real race car it probably had a vacuum pump for the crankcase that needed to be monitored. like this https://www.gzmotorsports.com/SVPK-L...-pump-kit.html

squared

It's to measure how fast all that cash coming out of your wallet because you own a Corvette..

mrvette

It tells you how hard your engine sux......

7T1vette

The main purpose for having a vacuum gauge in the dash is to recognize when you have developed a vacuum leakage problem. As with most analog gauges, you are checking for CHANGE from 'expected' readings as you operate the vehicle. If you normally see 18"Hg vacuum when you car is at an idle-stop condition, and you suddenly notice that it only has 14"Hg, THERE IS A PROBLEM UNDER THE HOOD. And, knowing what activities your car has recently experienced (oil change, engine work, etc), you can investigate where such work was done to see where such a leak might occur. This is the same approach for water temp gauge, oil pressure gauge, ammeter, voltmeter....it helps to make you aware that the engine is operating differently than in the past.