How much Vacuum?

[richs347]

To give you a better answer I need a little more info:

What size are the injectors?
Engine management system, chip, or stock computer?

Your combo appears to be beyond the stock computers abilities. If you have 42lb inj or larger you will most likely have to reduce fuel pressure at idle - at the detriment to higher rpms. The 6* is hurting the idle quality slightly. I see 12-13" at idle on my combo listed. (custom mild cam). As you increase your throttle position, the car will head toward 0 vacuum until boost is present. Then you hit the other side of the boost gauge and register boost. On a NA car, under WOT, you will see 0 vacuum.