Help with Tune - LQ9 Maggie Combo

I went to the track Friday night to try out the new combo. I logged all the runs and tried to tweak the tune a little bit each time. With the 243 heads and 11:1 compression, I was scared to push the timing. One of the issues I am experiencing is a lean spot when I am stalling the converter at the line. I tried to compensate by adjusting the boost VE table, but it was still lean. I selected GM:AFR as one of the PIDs and it was commanding 14.68 when I am commanding .79 lambda in the 105 kpa portion of the main ve table. Confusing.

If someone could take a look at my tune and log files and provide suggestions on what I could do to richen up the afr when I stall it up at the line. Also, what PID should I selected for commanded AFR? Any ideas on where I should be with timing after peak torque?

Thanks in advance!

I can't look at the tune/logs here at work - I'll take a look tonight... One thing to keep in mind - if you are trying to build boost while stalling it on the line, you may be seeing unburnt fuel - on the wideband, unburnt fuel shows up as lean due to the oxygen in it... can't always trust a wideband reading in a situation like that - same goes for those using a 2 step... How does it leave? is it bogging or pulling hard off the line?

GM.EQIVRATIO is the one to log for commanded...

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Originally Posted by BLK02WS6

I can't look at the tune/logs here at work - I'll take a look tonight... One thing to keep in mind - if you are trying to build boost while stalling it on the line, you may be seeing unburnt fuel - on the wideband, unburnt fuel shows up as lean due to the oxygen in it... can't always trust a wideband reading in a situation like that - same goes for those using a 2 step... How does it leave? is it bogging or pulling hard off the line?

GM.EQIVRATIO is the one to log for commanded...

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That would be great if you could take a look at it! I am pretty sure it is lean because I can feel at lower rpm's when driving and watch the wideband go 16:1 and feel the power drop off. It is a bit sluggish off the line.

Thanks for the correct PID. I will log it and compare actual vs commanded AFR's.

Your problem is you have PE commanding 14.63! With a custom OS, the way I would handle the fueling is to use B3647 to handle commanding outside of boost, and use B3613 and B3618 to command boost fueling. Read page 17 of the tutorial about using B3647 for semi-open loop. Then, you use AutoVE to bring actual to meet commanded... I'll attach a version of your tune showing you what I mean - run a comparison to the one you posted to see my changes...

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Originally Posted by BLK02WS6

Your problem is you have PE commanding 14.63! With a custom OS, the way I would handle the fueling is to use B3647 to handle commanding outside of boost, and use B3613 and B3618 to command boost fueling. Read page 17 of the tutorial about using B3647 for semi-open loop. Then, you use AutoVE to bring actual to meet commanded... I'll attach a version of your tune showing you what I mean - run a comparison to the one you posted to see my changes...

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Thanks for the information, it makes sense. It looks like I have 2 options;

I can select the PE threshold higher than I will ever see. For example, I don't ever go over 160 kpa, so if I select that as my PE enable threshold, then 14.63 will never be commanded. The problem is that my boost VE table will not represent commanded and actual AFRs?

It looks like using PE will be more accurate though and will allow me to use the Auto VE BEN MAP to compare commanded and actual AFRs. Chances are my boost VE values will be way off and need some rework? Also, I like the idea of being to go into semi open loop, right now I am running in open loop and sometimes the fueling is sporadic.

I am going to flash a tune and do some logs. Will report back. Thanks for the help!!

Yes, your Boost VE table will need work. The biggest problem was that it was in closed loop (B4205) - that means that even if you raised the threshold of the PE, it would not fuel using B3647 - it would always command 14.63. You HAVE to be in open loop for B3647 to be utilized in a custom OS... I would highly recommend using the PE to command boost like I set up the attached tune above... Once you get it tuned with the BEN, put it in semi-open loop...
No problem - I'll watch for your report back and help as I can...

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Originally Posted by BLK02WS6

Yes, your Boost VE table will need work. The biggest problem was that it was in closed loop (B4205) - that means that even if you raised the threshold of the PE, it would not fuel using B3647 - it would always command 14.63. You HAVE to be in open loop for B3647 to be utilized in a custom OS... I would highly recommend using the PE to command boost like I set up the attached tune above... Once you get it tuned with the BEN, put it in semi-open loop...
No problem - I'll watch for your report back and help as I can...

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Thanks for your help!! It now makes sense why the BEN MAP I was using was not getting consistent results with changes to the VE.

I loaded the tune you attached (thanks!!) and created a normal VE MAP and boost VE MAP in the scan tool. I made changes to the VE based on MAPs and it got the AFR much closer to commanded. I have attached the tune I worked on this afternoon. The VE and boost VE is far from pretty, but it is staying in the 14's in most part throttle conditions and in the low 11's at WOT.

I was getting some KR at low rpm high kpa areas, so I lowered the timing in those areas. Can you take a look at the low and high octane spark tables and let me know how you think they look? I also adjusted the IAT Multiplier tables so that once IATs go over 150 F, timing is pulled. The Maggie get's hot fast!

I took a look at it. I didn't look at your timing tables before, but what I would recommend is to use high/low octane timing tables more suited to naturally aspirated and use the boost timing table (A0010) to pull your timing for boost - that way, it pulls the timing any time you go into boost (much more reliable than trying to do it in the high octane table based on grams/cyl and rpm... make sense? I don't have time to do it for you tonight, but if you can take a stab at it and post up, I should be able to look at what you have tomorrow.

As for the VE tables, smooth out any large peaks or valleys and make sure you use filters before you copy and paste from the log...

Also - post up the logs next time - that will help...

You might consider a meth kit to help out with the heat and fuel quality - I highly recommend meth on any forced induction street car/truck...