Working on VE.. Rich Spot Question

[tatasta]

Hello,

I have been working on getting VE table dialed a little closer. When comparing the logged data to the B0101 table in the tune (both attached), what is the best way to use the data to adjust the tables. I did the cut and paste method and did not notice much of a change to B0101, which I hope means it was fairly close.

Anyway.... If you got the time, let me know any pointers or help.

Thanks

[joecar]

Did you do copy-with-labels and past-multiply-with-labels...?

Your ben map shows you are fairly close.

[tatasta]

Joe,

I did do the paste with multiply. It is good to hear that it is fairly close.

Should I continue to do long logging sessions at all types of driving and continue to update the VE?

Problem is, at least from my perspective, is that there is abundant numbers of members on here willing to give you their time and great advice but often I just don't understand why. I read and read other posts, threads etc. but just like adjusting the VE, I'm not always sure why I am doing what is suggested.

Anyway, I'll quit whining. If a cell in the BEN chart logs, say 0.98, how exactly does that relate to the same cell in B0101? Is it a % of the value in the VE?

Lastly, I attached a couple more items. On the AFR in the higher RPMs and MAP (high for me @ 5100' elevation), what is my best bet at getting the AFR at my target of 12.6:1? I am getting closer but not sure what to tweak next.

Thanks

[joecar]

A ben value of 0.98 means the corresponding cell in B0101 has to be multiplied by 0.98 to bring wideband AFR equal to commanded AFR.

The value 0.98 means 98% of the current value in B0101 VE table.

If your B0101 table is already corrected (most ben values are between 0.98 and 1.02, or even say some ben values between 0.97 and 1.03), then simply edit B3605/B3647 and B3618 to set your target AFR... think about which cells in those tables you're editing... some people have found 12.6 makes the best peak torque and 13.2 the best peak power (do this with B3618 and/or B3647)... some people just set it flat.

[5.7ute]

tatasta, some of the best information you will find is in RedhardSupras blog site. It can get a bit heavy, but I believe it is required reading for those beginning to tune who want to know why.

[nathans1987]

in your map of logged data check the coloured box. makes it easier to read.

[tatasta]

Thank you guys for the replies. I will check out Redhardsupra's site. Also, the BEN explanation clears up alot for me. I will get back on it this weekend.

[tatasta]

Hello,

I seem to be closing in the VE Table but the AFR is kicking my ass a little. Everywhere I can think of I am set to attain 12.6:1 actual and commanded but actual is still a bit rich.

On each WOT throttle pull I see a rich dip both when TP goes to 100% and again when I release the throttle (log and tune files attached). Is there a parameter/table that addresses this issue?

Last, I am lost on understanding and/or tuning both long and short term fuel trims. I will be searching and reading up on it tonight. Any particular reading material or resources? Any insight?

Thank you!

[ScarabEpic22]

Pretty sure those are the transient parameters that were added a few months ago. A few members have done some extensive testing with them yielding good results.

[joecar]

Bob,

I take it you corrected your VE (via ben paste/multiply) from log taken while in OLSD...

My friend suggested that if your WOT ben's are out you could correct the WOT portion of your B5001 MAF table (using the map for it)... if you're running CL mode (CLMAF) then this works only at WOT with zero LTFT's (i.e. no influence from trims)(otherwise you will have to run in OLMAF mode to do this)... and in MAF mode (OLMAF or CLMAF) this works only at WOT since at WOT the PCM uses the MAF exclusively (see B0120).

Also, with the auto trans (where the PCM tends to lug the engine by holding a higher gear at lower speed unless it sees significant throttle), there is a window at part throttle low-mid range RPM that promotes knock... my friend suggests keeping timing moderate in that area... carbon deposits on pistons may increase the abilty to knock, try some unleaded 100 octane to see if knock goes away (if it goes away then it's real knock).

[joecar]

Bob,

Erik is referring to the Dynamics parameters under the Fuel section.

[tatasta]

Hey Joe,

Yes,I did get the VE straightened up, even the WOT areas are at 98-99%. The car is running good. I just have trouble getting my actual and commanded to match. The actual tends to be .3 to .4:1 too rich even with the VE at 99% and fuel trims holding at zero. However, 99% (VE accuracy) of 12.4:1 (actual) versus 12.8:1 (commanded) is an AFR difference of ~3.15% so I'm not sure if I can get it much closer unless I command 13.2:1 to compensate for this difference and get 12.8:1 actual. Hope that made sense.

As for KR, I think most of my count can be cured by desensitizing Burst Knock. Most of the logged KR fits in just under the current Burst Knock (B6210 and B6212) settings.

I understand your point on increasing octane discern whether the KR is valid. In fact, I did increase octane to 96 and still see the same KR so I will adjust advance in those areas.

So, the last part is to request people's input on my timing curve. It's attached and specifically, does it roll off quick enough? Does it need to be changed in a particular area?

Thanks Joe and Scarab!

I almost understand some of this.... Almost.

[jfpilla]

[QUOTE=joecar;97600]Bob,



My friend suggested that if your WOT ben's are out you could correct the WOT portion of your B5001 MAF table (using the map for it)... if you're running CL mode (CLMAF) then this works only at WOT with zero LTFT's (i.e. no influence from trims)(otherwise you will have to run in OLMAF mode to do this)... and in MAF mode (OLMAF or CLMAF) this works only at WOT since at WOT the PCM uses the MAF exclusively (see B0120).

Have you addressed the issue as Joecar indicates?

[tatasta]

Have you addressed the issue as Joecar indicates?[/QUOTE]


Yes, I have calibrated the MAF table as suggested.

[jfpilla]

Have you addressed the issue as Joecar indicates?


Yes, I have calibrated the MAF table as suggested.[/QUOTE]

If you are rich versus commanded at WOT, then lower the MAF values in the WOT frequencies. The VE's have no effect at WOT.

[tatasta]

If you are rich versus commanded at WOT, then lower the MAF values in the WOT frequencies. The VE's have no effect at WOT.[/QUOTE]

Gotcha. I was curious if that was an option.

So, if I am ~ 4% off of my desired AFR @ WOT, would it be sensible to lower the MAF values proportionally? i.e. drop the 5500 rpm value of 50.95 by 4% to 48.912? That seems extreme so is it best to baby step instead by small amounts?

Thanks

[Chevy366]

Hey can't you tune the MAF as well , just like the VE , same procedure , just use MAF ?

[jfpilla]

If you are rich versus commanded at WOT, then lower the MAF values in the WOT frequencies. The VE's have no effect at WOT.

Gotcha. I was curious if that was an option.

So, if I am ~ 4% off of my desired AFR @ WOT, would it be sensible to lower the MAF values proportionally? i.e. drop the 5500 rpm value of 50.95 by 4% to 48.912? That seems extreme so is it best to baby step instead by small amounts?

Thanks[/QUOTE]
I wish it were that easy. Small absolute changes (baby steps as you say) and trial and error have been the method that worked for me. That is, when you're as close as you are by way of the MAF calibration method.
It can be tough on the A4.

[tatasta]

Yes, tha's pretty much what I have done along with getting the VE tuned up. Currently my VE is within 2% or better and my MAF values are set by alot of logged data. Now, as mentioned earlier, to close the gap in my AFR it sounds like tweaking the MAF values is the next step since that's what is referenced at WOT.

Things are coming together but I am still looking for feedback on my timing curve (attached in an earlier post in this thread).

Thanks everyone

[joecar]

I have some "Cliffs Notes" on my profile page: http://forum.efilive.com/member.php?u=10

[tatasta]

Thank you Joe!

[tatasta]

Well, I've got the MAF table and VE looking good. Actual and commanded are within a tenth at WOT. Car runs pretty damn well, BUT.

I can't for the life of me figure out where I am getting a half of degree pulled and why when I set B3618 to 12.8:1 that my logs show 12.84:1 commanded.

I realize it is no big deal in the end as far as how the car runs but I just don't see where it is getting changed or where my spark is getting retarded by a half of degree.

I attached my current tune and a couple of logs.

Thanks