Old May 22, 2008 | 03:58 PM
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MD SRT6
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From: Maryland
Default Re: 181-Pulley Fact, Fiction or Matter of Opinion?

Originally Posted by SRT6 Gang Member
To remain consistent with my “mod baseline” research; I patterned this thread title after SL55 Setup Fact, Fiction or Matter of Opinion?. Pulley/ gauge were installed yesterday and weather permitting, I will hit the track today making three passes to obtain numbers. I put about 50 miles on it last night driving normal (daily), moderately (quick acceleration), and hard (WOT). The car was already fast so my butt dyno has not changed and I need numbers to tell the story.

Side note:
My gauge is a combo that reads boost and A/F, let me know what you think about my readings.
  • On start up the boost gauge reads –8 to -7 and the A/F starts out optimal, then begins bouncing throughout the lean/ optimal/ rich ranges.
  • Under normal driving, boost level ranges from –6 to –4. While A/F readings bounces throughout the three ranges, never holding in any range.
  • During moderate driving, boost levels range from –0 to 8 and A/F readings hold slightly in the rich stage, then begins bouncing.
  • When at WOT, boost levels range from 13 to 15 and A/F reading becomes a permit fixture in the rich stage.
  • Any time I remove my foot from the accelerator boost reads –8 and A/F becomes a permit fixture in the lean stage. Once accelerator is reengaged boost level returns to “normal” and A/F starts bouncing throughout the ranges.
When you are taking your a/f ratio reading directly off the factory o2 this is normal. The factory oxygen sensor constantly looks at the rich/lean condition and tries to keep it in a range that optimizes fuel economy. and detect any abnormalities( switching as much as 100 times a minute from rich to lean). The only way to solve the problem is to get a seperate wideband o2/ Or consider it normal during daily use. It only matters under sustained wide open throttle periods, as this is the only time that power is made anyway and engine parts can get hurt. Running lean at idle and cruise is just conserving gasoline. The object is to make precise power under WOT only and conserve fuel otherwise. And a custom tune would take care of the problem of running too rich under WOT. Hope this helps.
 
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