nbnguy98
Probationary Member
- 11
- 0
- May 1, 2004
-
Herndon,
Virginia
Does anyone know? So it's tapped into the vaccuum line. When the engine is off, it goes to zero. But when the engine is running it actually goes negative (like a vaccuum). Not only that. it's measured in "inches of Mercury". Then when I start boosting it goes positive, gets to 0 and then peaks to about 12 PSI (which is a different unit of measure). So the question is why two different measurement of pressure? and why does it start in the negatives, passes 0 and then finally goes positive? Read the forms, it does seem that the stock turbo gets about 12 PSI, so I assume it's reading correctly.