My first car had a factory vacuum gauge as part of the gauge package on the console..a 66 Caprice 2 dr hdtp. I could get 19 mpg out of the 396 when I paid attention to the vacuum gauge.
A boost guage will give the same info since it has a vacuum side to it and you can get them to match a lot more guage faces!
Entertainment and information at the same time. A good va***m gauge can tell you alot about your engine's condition. Normal vacuum at idle with stock intake and stock cam should be in the 19 to 21 inch range with a steady needle. Cams with a lot of overlap or duration will lower initial idle vacuum but the needle should be steady, same with multiple carbs. My car with the 6 and two single barrels runs 17 inches steady. The vacuum gauge helped me with with carb synchronization and finding a intake vacuum leak. If you have vacuum wipers simply t the line to supply the gauge. Of course runnign the wipers will mess up the reading so make sure they are off when using the gauge as a diagnostic tool. read em and weep http://www.cl***ictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm
the 79 AMX that I'm building came with one from the factory. Pacers and Eagles with the accessory gauge package also had vacuum gauges. dan
I had a '68 Chrysler 300 that came with one from the factory. Unfortunately located on the console, still was useful. Try watching the gauge while 'drafting' a truck, even a P/U truck with uncovered bed (closed tailgate) - you'll see a marked increase in vacuum. And you thought 'drafting' was for NASCAR and 18 year-olds. And just FYI, vacuum gauges don't work well on turbo-diesels. Cosmo
One of the coolest and most expensive hot rod gauges that I've seen is a McCulloch combination gauge. It has vacuum to the left of zero and boost to the right of zero. Zero is at the top center similar to an amp gauge. It reads vacuum at idle and drops toward zero until the RPMs pick up and the huffer starts to make pressure.
Heres a vacuum gauge that I found in a box of my Dads old stuff. Its calibrated in MPG. Of course it wouldnt be accurate in most cases but it has a handle on the back to fine tune it. Its made by Cragg products and says 'Copyright 1938' on the face of it.
I had planned to install one small one for each carb to tune and watch while driving. Motorcycle guys use a set of guages to sync the carbs. Usually starting about $40 a set.
if your looking for old va***e gauges they are in GM mid and large size trucks they came with a va***e gauge for the hydrovac brakes
Got one in my 57 Olds with the 3x2's. Real challenge to keep the vacuum up and my foot out of the trips.
the guy who mentioned this days ago also said the buzzer was key...you learned to hate the sound and then would let up on the pedal...or start to salivate......he said it must have been a helicopter piece ..anyhoo it made it easier to monitor
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