I got a mechancial boost gauge but it came in the mail set at -10 inHG (vacuum) instead of 0 or near 0. Is there a way to adjust it so it rests on 0? I couldnt open up the damn thing without feeling like it would break, I tried to open it on the rim part. Keep in mind its mechanical, since electrical boost gauges set themselves. I read that once its off 0 youre pretty much screwed correct?

If you bought it new just send it back and get another one. If it's used it may be possible to open it up and mess with it but usually they aren't off by that much. Sorry to say but this one is probably not useable.

My HKS boost gauge always at -0.5 when the engine runs. is this normal?
brandon, I didnt mean to hijack your thread, but I kind of in a similar situation.

I've been wondering about the same thing with my boost gauge. It reads up to 2.0 bars (kg/cm^2) straight to the right and 0 straight to the left but it never rests on 0. Instead when not on boost it goes down below the 0 mark and has a few lines marked with a mmHg measurement. I'm guessing that's just a smaller measurement since there is still some air flowing thru the turbo when the engine is running. Maybe your gauge is like that too?

Mine is measured in Kpa. Usually it reads -0.5 Kpa when idle. I dunno if this is normal. I bought the car used, it reads like that when I got it.

Any idea?

Idling, it should have a good vacuum. 0.5 kPa is only about 0.07 psi, so that's pretty close to zero. Are you sure you're reading the scale correctly?

Oh man guys....your engine draws air IN while running. You should see negative pressure on the guage while at a standstill. This is normal.

But yeah, in the box, I don't believe it should be reading a negative pressure. Unless the package was sealed...

Oh man guys....your engine draws air IN while running. You should see negative pressure on the guage while at a standstill. This is normal.

But yeah, in the box, I don't believe it should be reading a negative pressure. Unless the package was sealed...



What box?? what package is sealed?
I haven't checked my air filter for a while. I dont think it's related to boost gauge. am i correct?

I think REX8 was answering Brandon's original question. Sounds like HIS guage was reading 10" of vacuum before he even installed it. Mulder already answered that one; if Brandon just bought it, send it back cause it's defective.

Yup, I was talking about his BG. If the package was vacuum sealed, you could possibly see it reading a negative pressure while still in the package... :lol:

Haha yes it was -10 inHg int he box. I have made arrangements to return it. However I might have a better solution (quicker). I did the insurance thing for 2 extra bucks, is there a way to get my money back from USPS?

And as for the other "hijacks" no problem. Your gauges are normal, they should be reading a vacuum of about -.05 to -0.06 when the car is idling, and even more negative when you are decelerating. The negative manifold pressure is normal in all cars, its the basis of the vacuum system. When its + then theres the fun :D