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Boost/BST on ScangaugeII

S

showtastiik

New member
So my RPM been acting a little slow and car has been running rough lately. BST is showing -8 at idle. I'm sure anything in the negative is bad, especially negative increases when I'm actually driving. I'm guessing BST is boost right?... Where should I be looking for this fix?
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"Boost" readings will show negative on a gauge when idling and driving because the "boost" gauge is like a math of two parameters or whatever.

I think logging boost is dumb because I'd rather log the actual MAP sensor data itself. I haven't owned a scangauge two before but the Aeroforce scangauge would read the MAP in/hgs parameter and would go from vacuum to boost all on the same channel without having to log a specific boost parameter.

Or you can log MAP kpa and learn to read KPA above 100kpa to get your boost number. Like 130kpa is 4.3psi, 140kpa is 5.8psi and 150kpa is 7.25psi.
 
Scangauge is in psi, -8 psi is -16.28 inches of mercury. so that is normal at idle. I don't know how else the gauge would get the information than from the map sensor and just converting units. That is a about right for idle. Not sure why it would be running rough unless you were seeing something like 14 psi at idle on a stock car. My scangauge rpms do not match my real gauges if thats why you think rpms are low.
 
I have CNC Ported Heads on 130# springs, CAI, zzp coil/Plug wires, oversized radiator, 180 Tstat and just now added 3" downpipe and front plog.. In my 04 Pontiac Grand Prix Supercharged...... Hope that's enough for a 3.5 Pulley. About to scan and check tomorrow..............

Double checked everywhere and found and fixed the boot behind the Supercharger on the side of the PCV valve, that is connected to the throttle body air intake (whateve the name of that is, please tell me)

Also the T under the SC snout, that is connected to the LIM was cracked as well. IDK if you guys can see that oily gunk splattered on the snout but I also found that my axle took a big dump.....
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