PCM Diagnostics & Tuning HP Tuners | Holley | Diablo
Sponsored by:
Sponsored by:

For WOT AFR : VE or MAF?

Thread Tools
 
Search this Thread
 
Old 06-24-2010, 08:34 AM
  #1  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
baezi z06's Avatar
 
Join Date: May 2009
Location: Iceland
Posts: 523
Likes: 0
Received 0 Likes on 0 Posts

Default For WOT AFR : VE or MAF?

hi

when adjusting fuel for AFR @ WOT are people making changes in MAF table or the VE table??

baezi
Old 06-24-2010, 09:46 AM
  #2  
11 Second Club
iTrader: (5)
 
nocooler's Avatar
 
Join Date: Apr 2007
Location: Mid Michigan
Posts: 605
Received 62 Likes on 40 Posts

Default

If the MAF table is tuned/re-curved for your car - then it should be a case of changing the PE table accordingly, as you aren't increasing airflow.
Old 06-24-2010, 11:52 AM
  #3  
TECH Fanatic
iTrader: (1)
 
RedHardSupra's Avatar
 
Join Date: Sep 2003
Location: Laurel, MD
Posts: 1,904
Likes: 0
Received 1 Like on 1 Post

Default

if you tune both of them then you dont have to worry
Old 06-24-2010, 02:34 PM
  #4  
UNDER PRESSURE MOD
iTrader: (19)
 
The Alchemist's Avatar
 
Join Date: Nov 2001
Location: Doylestown PA
Posts: 10,813
Received 13 Likes on 10 Posts

Default

I think the original poster's question was at WOT, which table is the pcm using to calculate fueling.
Old 06-24-2010, 02:37 PM
  #5  
TECH Junkie
iTrader: (5)
 
redtan's Avatar
 
Join Date: May 2008
Location: Belmont, MA
Posts: 3,764
Likes: 0
Received 15 Likes on 14 Posts

Default

My tuner commanded a certain AFR at WOT (12.6), then used the VE table and made adjustments there until the car hit the desired 12.6 AFR at WOT. This was in an MAFless speed density tune, but even with a MAF the fueling is calculated from the VE table.
Old 06-25-2010, 06:06 AM
  #6  
11 Second Club
iTrader: (18)
 
MattysTA's Avatar
 
Join Date: Jul 2004
Location: NJ
Posts: 255
Likes: 0
Received 0 Likes on 0 Posts

Default

unless your running with SD then you would change it with the maf since the factory setting is maf only for airflow 4400rpms and up. below 4400rpms its a combo of the maf/ve table the pcm uses for fueling.
Old 06-25-2010, 08:20 AM
  #7  
TECH Enthusiast
 
macca_779's Avatar
 
Join Date: Nov 2006
Location: Katherine N.T Australia
Posts: 620
Likes: 0
Received 0 Likes on 0 Posts
Default

As above you have to do both unless above the MAF only parameter which is normally ~4000rpm
Old 06-25-2010, 10:32 AM
  #8  
9 Second Club
iTrader: (2)
 
BLK02WS6's Avatar
 
Join Date: Jul 2002
Location: on the dyno tuning in MD
Posts: 2,583
Likes: 0
Received 1 Like on 1 Post

Default

Originally Posted by RedHardSupra
if you tune both of them then you dont have to worry
What he said...
Old 06-25-2010, 04:02 PM
  #9  
9 Second Club
iTrader: (24)
 
HUNTER02SS's Avatar
 
Join Date: Oct 2006
Location: Kennesaw, Georgia
Posts: 2,796
Likes: 0
Received 1 Like on 1 Post
Default

You tune the VE and Maf for drivabilty to around 4000rpm, and then you can tune the VE as well for WOT and then tune the MAF for WOT to get your desired AFR. This way if your MAF ever happens to go bad, if tuned properly you will never know the MAF failed other than the check engine light on the dash..
Old 08-15-2010, 01:03 PM
  #10  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
baezi z06's Avatar
 
Join Date: May 2009
Location: Iceland
Posts: 523
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by HUNTER02SS
You tune the VE and Maf for drivabilty to around 4000rpm, and then you can tune the VE as well for WOT and then tune the MAF for WOT to get your desired AFR. This way if your MAF ever happens to go bad, if tuned properly you will never know the MAF failed other than the check engine light on the dash..
i'm now finishing calibrating my VE and the MAF to 4000rpms....

but if i wante to calbrate the WOT
should i then adjust the desired numbers in PE table,
and log the WOT
should i calbrate in the MAF table or in the VE table

or maby both

thanks

Baezi
Old 08-16-2010, 05:08 AM
  #11  
TECH Enthusiast
 
macca_779's Avatar
 
Join Date: Nov 2006
Location: Katherine N.T Australia
Posts: 620
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by baezi z06
i'm now finishing calibrating my VE and the MAF to 4000rpms....

but if i wante to calbrate the WOT
should i then adjust the desired numbers in PE table,
and log the WOT
should i calbrate in the MAF table or in the VE table

or maby both

thanks

Baezi
Adjusting the PE only alters the commanded AFR. You won't have to touch that as what your doing by tuning your MAF and or VE is getting the commanded AFR to match the actual AFR.

Above 4000rpm the controller is set (stock value) to run exclusively off the MAF. Its always best practice to tune the VE here too but you have to turn the MAF off the same as you would when tuning below 4000rpm (which I hope your doing as if your not you'll never get it right).
Old 08-16-2010, 09:56 AM
  #12  
TECH Enthusiast
Thread Starter
iTrader: (2)
 
baezi z06's Avatar
 
Join Date: May 2009
Location: Iceland
Posts: 523
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by macca_779
Adjusting the PE only alters the commanded AFR. You won't have to touch that as what your doing by tuning your MAF and or VE is getting the commanded AFR to match the actual AFR.

Above 4000rpm the controller is set (stock value) to run exclusively off the MAF. Its always best practice to tune the VE here too but you have to turn the MAF off the same as you would when tuning below 4000rpm (which I hope your doing as if your not you'll never get it right).
the MAF is off , when i´m calibrating VE tablet...

then if i understand you right. after 4000 for WOT i should do a MAF only calibrate and use the PE tablet numbers do get right calibrateing numbers for example if i adjust all collums in PE for 12.6 at WOT i should get the MAF only WOT readings to that and only change in MAF Hz tablet

am i on the right track here....

Baezi
Old 08-16-2010, 11:06 AM
  #13  
11 Second Club
iTrader: (1)
 
69LT1Bird's Avatar
 
Join Date: Sep 2007
Location: Lapeer, MI
Posts: 2,310
Likes: 0
Received 4 Likes on 4 Posts
Default

Grab the free guide in my sig, it should help you.



Quick Reply: For WOT AFR : VE or MAF?



All times are GMT -5. The time now is 10:32 PM.