Speed Density Question

[Brad Kimbler]

So I have been playing around with a bolt-on Car (1999 Z28 auto) headers and intake lid pretty much.

I disabled the MAF per tutorial and the car seems to run pretty good. Ther is still the 02 sensors adj. fuel trims 1-2 %.

My question is..Is this all I need to start Speed Density tuning..disable MAF? Can I keep the long and short term fuel trims with the upstream O2's? I think it would be nice if the VE table is rimght the get rid of the maf as an inlet restriction..thoughts?

Thanks you.

[joecar]

Are you seeing a MAF DTC... if a MAF DTC has not triggered (immediately on engine start) then you're not in SD.

Keep trims only if you're planning to use these to correct the VE... otherwise if you're planning to use a wideband (you should) then you need to disable all trims.

The only way to know if the VE is correct is to see if the wideband lambda correlates exactly with commanded lambda.

MAF is not a restriction.

[joecar]

Have a read of these:
- Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log) (http://forum.efilive.com/showthread.php?15236-Calc-VET-correcting-MAF-and-calculating-VE-(in-single-log))
- Calc-MAFT-correcting-VE-and-calculating-MAF-(in-single-log)-gt-reverse-of-Calc-VET (http://forum.efilive.com/showthread.php?16413-Calc-MAFT-correcting-VE-and-calculating-MAF-(in-single-log)-gt-reverse-of-Calc-VET)
- Summary-Notes-post#29 (http://forum.efilive.com/showthread.php?14188-Summary-Notes&p=148674&viewfull=1#post148674)

[ddnspider]

X2 keep the MAF. I've been playing with my 98 A4 bolt on car and have the tune pretty spot on and the MAF is definitely NOT a restriction.