ivai

Hi all, I've recently installed an Auto Meter boost/vacuum gauge, having it hook up directly to the fifth port on Laust's vacuum manifold. At idle it only reads about 12 inches, though idle seems solid, and at WOT up to 15psi or so of boost, though I still have the stock wastegate... Might I have a shimmed wastegate? As far as I can tell there is no boost controller on it.. Maybe the gauge is out of whack?

TIA,

Mike1982

You should only be about 11ish or even 12 at most if the car is stock, which I am guessing. The computer will cut the fuel above that on the over-boost protection, YOU KNOW WHEN THAT HAPPENS!! Another thing to do is go to a shop that does race work (the place I go does street and race) and they will hook it up to a gauge and tell you what it really is. Plus they can tell you if any control is on it.

ivai

Yeah... Lol I'm pretty sure i'd recognize if there was a LBE or something installed, I've had the intake manifold off before (to clean the ICV) but oh well.. Perhaps I'll try taking it to a shop and see what I can do.

streckfu's

Mine indicates 12in.hg. when idling and 18 when driving and off throttle.

theedge

Mine shows 20 in Hg at idle when warmed up. Thats the normal vacuum.

How did you install it? Did you use soft rubber hose for the whole run from manifold to the gauge?

streckfu's

Come to think of it, mine does show 19-20 after warm up....

Bri Bro

Might want to look at the gauge with the motor off and see if the gauge reads one atmosphere. This needs to be adjusted for altitude and local pressure but these changes tend to be small

ivai

Methinks its time for a vacuum leak search... darn. The gauge reads 0psi when the car is off, I would assume that means 0psi from normal atmospheric pressure.

streckfu's

Zero when engine is off is correct.

ilikemy944

Just for something interesting, with my car off, I show 1+psi boost.

theedge

Id suggest that before you do that, take the same gauge and a short length of those and connect it in the engine bay.

IF you used a long run of soft rubber hose, its possible that the vauum sucks shut and that messes with the reading. Ive seen it on a Toyota truck. 12 in of Hg when warmed up would make for a fairly ugly idle I think.

mroberts

Shameless threadjack (sorry)

I have APE chips, and (I think) a shimmed wastegate. I used to get up to 2.2 bar on the stock gauge, but now I only get to 2 bar. My mechanic replaced the J-boot.

Would the new J-boot give me less boost, or do I likely have a leak ?

What should warm idle RPM's be ?

facboy

how can u see 2.2 on the stock gauge? it only goes to 2.0 doesn't it? APE chips aren't rated to 2 bar are they? you're just meant to use them with the banjo bolt, no wastegates shims or nothing.

streckfu's

Do you mean with the key turned on without starting the engine? If so, that is normal. You are seeing 1 bar which is atmosphere.....

hosrom_951

Try removing one of the vacuum line for the CV, you would hit 20+psi and the factory gauge would read 2.2bar (well, it isn't marked, it stops reading at 2bar but goes over that )