I'm tuning Speed Density and why I'm trying to figure out is how do I setup my spark advance table? If you look at the table, it is in Grams/sec (MAF) but how does the computer know this info (what Grams/sec are being flowed) and more importantly how do I know which cell I am in as I go driving around so I can advance/retard as needed?

 

spark table axis is grams/cyl (airmass per cylinder). Our software incorporates a histogram display in the scanner that lets you see exactly where in the spark table you are operating - also for knock retard. (BTW, to help with your SD tuning we also have LTFT, STFT and Wideband AFR histograms (optional with EIO cable) that are laid out in the VE table format.

hope that helps,

Chris...

 

sorry....yeah it's grams/cyl....


but I'm still trying to figure out HOW this works.....it's not like I have a MAF anymore......is the computer back calculating from the VE table to figure out the airmass?

 

yeah the VE table is used.

 

is there an easy way to figure out what cell is being used for what advance point?

 

There must be a CylAir calculation to index spark. With
no MAF it has to come from the speed density air mass
calculation. You have to use Dynamic Cylinder Air PID
and RPM to see the spark point, you have to use RPM
and MAP to see the VE table point that any frame is at.

I've seen some stuff about maybe when you fault the
MAF you end up using the low octane table. I can't say
about that.