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View Full Version : Tune VE and MAF tables or leave VE stock and tune MAF only



BlackGMC
August 4th, 2008, 03:40 PM
I was wondering what most of you NA guys do... Do you tune both the VE table and MAF table or leave the VE table stock and tune the MAF solely.... Would there be any difference between the two methods?

The Alchemist
August 4th, 2008, 06:39 PM
Do both, with the VE corrected you get much better transient response. The Maf needs a lot of work over 7000hz, runs rich. Under 6000hz you can trim it up as well to get best fuel economy. Hope this helps.
Mike

TFZ_Z06
August 4th, 2008, 07:05 PM
I was wondering what most of you NA guys do... Do you tune both the VE table and MAF table or leave the VE table stock and tune the MAF solely.... Would there be any difference between the two methods?

So far, I have only tuned the VE table. One could argue that after you add an aftermarket airbox, its skews the maf readings anyway, so tweak the MAF too is probably the best answer.

Sequentially tune:
OL SD VE
CL SD VE WOT
CL MAF

At this point, I'm trying to clean up the VE table as much as possible before proceeding to other tuning. I did play around w/PE vs RPM, but plan to retune the MAF to = PE vs RPM A/F data after 4000rpm. I tried OLSD, but its only good for idle, the CL MAF setup beats its big time on top end.

One problem I might expect by tuning MAF onlyis that at a given Hz airflow,
you could be at numerous points of the VE table, thus resulting in different A/Fs at each if the VE table isn't spot on, so I'm guessing that tuning the 1 dimensional MAF curve won't cure the entire VE table.

At less than 4000rpm, I would think its VE table only, then after 4000, the MAF. I would shoot for the PE vs RPM A/F settings for dialing in the MAF. I don't think its a bad idea to dial in the high KPA VE data (95kpa+) first to get close to your desired PE vs RPM, then tune MAF to balance.

I think the big diff is the drivability would be reduced without working a little
on the ve table. Most WOT A/Fs are easily cured w/PE vs RPM otherwise.