Noob question on ve afr

[Ron_LT1]

Hello.
If I'm tuning VE tables with a wideband Open Loop, am I targetting 14.7 all over the ve table or aiming to match the the open loop afr table numbers


Ron

[MO LS Noobie]

Welcome. There are others on this site that will help you with the earlier OBD1 stuff. Typically they will want to know what computer and operating system you're running, and also some details on your vehicle. Have fun

[LeMarky Dissod]

If I'm tuning VE tables with a wideband Open Loop, am I targeting 14.7 all over the ve table?
or aiming to match the the open loop afr table numbers?The part of the table that represents the most sedate driving (drivin Miss Daisy), 14.7 is fine.
In fact, for decelerations (those not covered by DFCO) feel free to target as lean as 15.2 - 15.3, if you're froggy; at low loads, exhaust temps will not go up, so NOx will stay down.

Once load goes over and above that used for the most gentle accelerations (think CAFE MpG tests), target 14.1 or the Open Loop AFR, whichever is richer - although it won't hurt to use the leanest Open Loop AFR table you can find for your vehicle.

[steveo]

you could target a safe afr like 13.5:1 and disable power enrichment and accel enrichment then tune to that target.

you could target 14.7:1 and set a static power enrichment afr then filter your log and tune to both

you could leave your afr table alone and log the afr target too then tune the difference

lots of ways to do it

depends what data you have

for a beginner the first option will probably yeild the cleanest ve table the most quickly with no risk of mistakes or blowing the engine up

[badgta]

Question.. Why would you not wish to use the Closed loop feature while cruising, part throttle etc?!? It would yield the best MPG...

Just curious is all.. Your reason i mean...

[steveo]

tuning the ve table with a wideband in open loop is by far the fastest way to achieve a correct ve table.

you can still use closed loop after tuning your ve table with a wideband


It would yield the best MPG...

that's rarely true. varying AFR across a load axis often produces the best fuel economy. factory cars can't really do that sometimes for emissions reasons though. depending on the engine i often tune 15.5-16:1 at light loads and taper down to 14.7:1-ish at medium loads. old cars can't do that in closed loop but newer cars with factory afr sensors sure can.

[badgta]

For getting in the "BALLPARK" sure.... But i mean, in the long run, once you are close.. Closed Loop is the way to go personally due to the ECM being able to compensate for varying conditions, etc.

Just my thoughts.. Especially if you have a upgraded ECM such as EBL etc.

You seems pretty knowledgeable.. Would love to converse with you on tuning sometime... Get some insights from ya.