Boost vs. Boost/Vac - Toyota Nation Forum : Toyota Car and Truck Forums

darkknight1085 · 08-29-2007, 12:11 AM

I was curious what you would want the boost/vac guages. I've always seen them but never understood what exactly they are for...

***HATEnFATE*** · 08-29-2007, 09:17 AM

You'll know if your runnin proper vac pressure.

tinico · 11-08-2007, 06:29 PM

to make sure your turbo is running good

***BLUEMEANIE*** · 11-08-2007, 10:24 PM

I use one cause its fun to watch.

THansenite · 06-04-2008, 12:09 PM

Boost is for superchargers since they don't see vacuum pressure. They are always boosting when the engine is running. Boost/vac gauges are for turbos since at cruise, the engine is sucking in air faster than the turbo is forcing it in, hence the vacuum. However, when you put the petal down, it goes into boost (obviously). I like being able to meter how much load I am putting on my engine so that I only go into boost when I want to so that I can save a little bit on fuel.