I got one of those stock column mounted rubber pod with boost gauge in my WRX. When idling, what should the gauge indicate?

It's one of these:

 

0. You're not building boost.

 

I guess there is a problem with my Turbo then since it's between -.05 and -.1

 

False. You should be in the negative due to manifold vacuum. I don't know the exact number, but I'll check the next time I'm in my car. I'm not trying to flame you impreza01, but you shouldn't post something unless you know for sure, otherwise you're just likely to freak people out.

-Chris

 

yeah it should be in the negatives, not 0

you do have vacuum pressure pulling air into the car so it reads as a negative pressure

 

Starting to feel better now...thanks guys!

 

mine is negative. Came with the car so it wasn't a problem with my installation. hehe.

 

on my wrx, idling is like -15 to -20 I think(on a 30 PSI gauge)? never higher then 13.5ish though.

 

The boost gauge reads pressure above atmospheric.

Atmospheric pressure is about 14.7 pounds at sea level.

So if you are running your car with your throttle closed at idle, your car needs very little oxygen so the amount of pressure at the throttle body will be a small number above 0 pounds pressure. If your gauge reads in PSI, the number should be -(10-14) or so. Most gauges have a weird system for the negative parts.

 

Yeah, I have the factory column mounted guage as well and it's always around -.15 when idling.

 

Thanks, I guess my friend's boost gauge needs to be fixed then. It shows 0.

 

It will read 0 if it is boost only guage, as in no vacuum scale. Again, I wasn't trying to flame, just trying to keep unnecessary freak outs to a minimum. Lord knows I spouted my fair share of false/misguided info.

-Chris

 

WTF is mpA?

 

mpa=megapascals

 

= pc load letter