B3647 Question??

[jamesbond2509]

If I set B3647 to 14.4 - is that enought to set the PCM to open loop? and what is the ideal setting to do auto VE tune. (On the 105Kpa setting it is set to 11.8) Please advise.

Thanks

[Tordne]

OK so this is how it all works :)

The B3647 table is only used in Open Loop fuelling mode.

To get into Open Loop set:
- B3801 to Disabled
- B4205 to maximum value

Once you are using the B3647 table there are a couple of things to note:
1) If you command an EQ Ratio of 1.00 then you are actually in a custom mode (unique to OS3 & 5) called semi-Open Loop where the O2 sensors are actually used to trim fuelling.

2) Setting a field to something other that 1.00 (both higher and lower) you will be in normal Open Loop mode.

Obviously you don't want to be doing an AutoVE in Semi-Open Loop cause if you add 2% to your VE table the trim will just take 2% out as correction ;)

Hope that helps.

Cheers,

[kbracing96]

I set mine to 14.7 for autotune and there is no STFT's going on ;) just open loop.

[Tordne]

I run 14.7:1 all the time - ecept when enriching for higher loads (i.e. WOT). Open Loop full time baby!!

[TAQuickness]

:D I like 3647 :D

Believe it or not, I get better mileage with this fueling combo as compared to commanding an EQ of 1.0

[jamesbond2509]

1 set it to 14.7 and have experenced a dramatic increase in smoothness after autoVE. Thanks!

:cheers:

[Tordne]

Glad it's working out for ya!

[RetroAus]

14.7 :1 only keeps the EPA happy....best mixture for emmisions not economy

[Tordne]

What are people opinions on AFR's for Economy?

TA is talking slightly rich, whereas I found sites and posts whih suggest lean (~ 15.4:1)

[TAQuickness]

I would say monitor the MPG pid while using bidi at steady state cruise.

[Tordne]

I can just see it now. A post in a few days something to the effect "I can report that 15.4:1 is in fact the best for economy, but I can also confirm that it causes serious accidents" ;)

[oztracktuning]

Mine has lots of 15.5:1 a low load and lots of timing. It did 9.5L/100km the other day 30mpg over an extended period at 110kph (70mph) that with 3.73 gears and an A4. Any leaner than high 15 and it starts to run rough. It has 10.7:1 comp and baby cam.

[dfe1]

Anybody have what's needed to build an MPG pid?

[dc_justin]

Anybody have what's needed to build an MPG pid?

Dig through this sucker, starting around post 15-20:
http://forum.efilive.com/showthread.php?t=1667

[joecar]

Dig through this sucker, starting around post 15-20:
http://forum.efilive.com/showthread.php?t=1667And post #27 has a calc_pids.txt file attached. :cheers:

[dfe1]

And post #27 has a calc_pids.txt file attached. :cheers:
Thanks. Got things updated and I'll test on the way home from work.

[ViolatorTA]

I tried the same with B3647 set at 14.63 and was going nuts trying to tune it. Now I know why so I too set B3647 to 14.7 and it defaulted to 14.73. After logging a few times I realized that the idle cell was always lean so I logged commanded fuel and realized that 14.63 was commanding in idle areas, sitting and off the gas coasting. I added excluding commanded AFR below 14.73 to the filter and my BENs started looking better but still had a few problem areas. After getting home tonight I started looking through and noticed that B3607, Open Lean Limit(idle) is set at 14.63 which I believe is keeping commanded AFR at 14.63 when in idle conditions so I set it to 14.73 and will be logging more in the morning. I'll update afterwards.

Anyone else notice this and does what I saying sound logical?


Shawn

[Tordne]

Having B3607 at 1.00 (EQ) or 14.63 (AFR) should be fine. If you are commanding 14.7 it should be at that value.

[5.7ute]

I put b3647 to an e.q of 1.00 and then attempted autove. I also logged the stft trims & had up to 3% correction when driving.
Should I just continue doing it this way until the stft stop correcting or zero out the correction factors until autove is complete.

[Tordne]

You need to change B3647 to NOT 1.0 EQ (14.63:1 AFR) as this put the fuel system into Semi-Open Loop and trimming will occur with the O2's. With it set like this if you added 2% to the VE you should see the trims increase by -2 for example.

Set the non enriched portions of the B3647 table to something like 0.995117 EQ (equates to 14.7:1 AFR) anf then d the AutoVE.

Once done you can go Semi-Open Loop if you wish. I run full Open Loop all the time BTW.

[5.7ute]

You need to change B3647 to NOT 1.0 EQ (14.63:1 AFR) as this put the fuel system into Semi-Open Loop and trimming will occur with the O2's. With it set like this if you added 2% to the VE you should see the trims increase by -2 for example.

Set the non enriched portions of the B3647 table to something like 0.995117 EQ (equates to 14.7:1 AFR) anf then d the AutoVE.

Once done you can go Semi-Open Loop if you wish. I run full Open Loop all the time BTW.
Thanks for the quick reply.

[ViolatorTA]

OK...Rather than start yet another OS5 question post I'll put this right along this one since it still has to do with B3647. Here goes......

I set B3647 to 14.7(all cells), B3601 is set to 14.63 as per AutoVE, B3801 disabled, B3803 is set to 140C, B4205 is 122C(all cells), DFCO is off and I set B3807 to 14.7. I'm still getting 14.63 commanded at idle and low RPM/MAP cells. I did take notice to B4108 is enabled and when I log STFT's they are updating in these regions. Should I set B4108 to disable or does any of this matter. When I log and update VE idle reads lean on the WB no matter how many adjustments are made.


Thanks in advance
Shawn

[Tordne]

Send tune to andrew at holdencrazy dot com if you don't mind and I'll take a look...

[ViolatorTA]

On its way and thank you.

BTW, It's cammed with a 231/237 TSP, LS6 intake, Ported TB, smooth bellows, TSP lid, Absolute Speed Stage II 5.3 heads, Jet-Hot longtubes, off road Y-Pipe(no CATS) and descreened MAF(disconnected).

[Tordne]

Tune coming back... I'm out for a couple of hours. Let me know how it goes.

[ViolatorTA]

Will do.

[5.7ute]

I have done auto VE numerous times & still cant get them to remain close. I think this is due to the iat VE multiplier as the intake temperature here can vary up to 25 deg c on a drive. Is there any way I can dial in the iat VE multiplier to correct this problem or should I set this to 1.0 ?

[kbracing96]

Use these number in A0014 and it will stay much more accurate :) Thats what I use ;)
0.911377
0.922607
0.934082
0.946289
0.958984
0.972168
0.985596
1.000000
1.014892
1.030517
1.046875
1.063965
1.081787
1.100830
1.120849
1.141846
1.164307
1.187988
1.213135

[Big Kahuna]

Will do.

And what was the result, and the changes??
Resolved?