Tune Advice/Tune check

[PlatinumPuma]

Hello,

I will start off with my car, 2003 Z06, Mods include only a Vararam intake, and ARH Catless Long Tubes so I didn't think many changes would be needed.

My first go at messing with any of the tables or tuning in general so I am hoping to get a sanity check and I guess a performance review. To start off I wanted to go though my VE Tables, so attached you'll find the logs and progress I made. I started with adding the 1.15 to the VE table that was recommended, and went from there. I think it went smooth, but I certainly need to work on throttle control and hitting more cells for more counts. I also think I should have had 2 decimal points in my histogram to make them more accurate. I probably could have went for a couple more revisions to get it dialed in a bit more, but time constraints got me.

At no point did I think my car was in any danger of going boom so thats was a relief......until I switched over to MAF only. Please let me know what you think, and what improvements could be made. I have not touched the PE, Timing, MAF, or any other tables at this point(next post)

Thank you all in advance for your advice and opinions!

John

[PlatinumPuma]

Just realized I am missing some of the Logs for SD4 and 5......rookie move, apparently did not save them.

Anyways, onto the MAF. got the car running solely on the MAF, First start up and revs......19+ AFR......wasn't comfortable with that so I went to the MAF Cal, multiplied by 1.15, fired up, around ~16....still not getting warm fuzzies, multiplied by 1.15 again, got down to 12-13 ish. Much more comfortable start point.

Again I didnt have my charts set to 2 Decimals so I feel I missed out on some accuracy, but overall the process was smooth, monitored AFRs as I accelerated pretty aggressively to hit as many Freqs as I could, made changed, rinse and repeat. Tomorrow sometime I should be able to get a regular log of how its looking, But for now I am mostly hoping for just a sanity check again.

I really appreciate the help and advice! This forum is so full of information! great resource for sure!!

Threw in my modded stock tune before I got brave enough to change important tables in case anyone wanted to see that.

[cobaltssoverbooster]

I use no decimal or 1 decimal. the second decimal is like a fart in the wind...

13afr compared to stoich 14.7 is error -11.56
12.99 afr to 14.7 is error 11.63% . thats 0.07 or .1% difference. the delta in accuracy is not really there to make it worth while

i have the wrong computer to read files but dont sweat your decimals

[PlatinumPuma]

Hello all,

I have been messing around some more with the tune. Added a bit of fuel overall to get more negative numbers than positive. Still mostly 0, -1s and -2s, but there are a few spots where I have some room for improvement. Primarily in the 15-20 kPa throughout the revs. Though I am being stumped by my PE commanded VS actual AFR......it is commanding exactly what I have set in my Power Enrichment table, but the actual is typically around 3-5% richer.

My running hypothesis is its adding fuel from the few positive LTFTs I have, but the issue with that I have, is PE is typically coming in when it is in the 95-100kPa range, and my LTFTs up there are 0-2 across the board with a couple dipping lower. Would the PCM be commanding the additional fuel from the "highest" LTFT it has, or would it have to be in the cells its currently running through.

I am going to keep working on getting all the cells to around -4 - 0, but for now I am curious why my commanded is not matching my actual....even though its commanded is matching what I have in the tune.

Attached a log from tonight, and the current revision of the tune. Thanks in advance for any advice you guys can give me!

John

Edit: added my Channel Config that I updated

[5FDP]

Commanded is commanded, what you see in the actual can always be different. If there is a difference you need to add or remove fuel from the airflow model to reach the commanded value.

So if you've got most of your stuff squared away you can look how your current tune file is setup to run. Above 4,000rpm it's going to be using the filtered MAF values, so in this case most of the time that your commanded and actual AFR are different is above this rpm range.

Go into your MAF curve as well and look at the log here to reference where it's happening. So above about 9,000hz you can remove about 2% worth of fuel.

Highlight the section from 9,000 to 12,000 and multiply by .98 to remove 2%.

Do that and smooth the table. Flash that in and make another log. See if your actual AFR/Lambda goes from right now around .83ish to up around .85 to .86, which would be only .01 to .02 off of your current commanded value in those area's.

This is a quick and easy way to see if that small change will get you closer to the commanded AFR target you are trying to hit.


If you had setup an AFR or lambda error against the commanded AFR, you'd see this error there. And if you had the tune setup to calibrate the MAF or VE table, you could copy that error and paste special by half in either table to dial in the airflow model better. Just note that MAF and VE tuning this way have to be separate from each other with each side either put into speed density only and or MAF only mode. As well as having all fuel trims and closed loop functions disabled to prevent any computer related fuel changes. Only the wideband will show where the corrections need to be made.

[PlatinumPuma]

Hey,

Thanks for the tip! I just realized earlier in the tune, it was pulling a lot of fuel ie +3/4 in the LTFT table, so I went in and added (multiplied by 1.04) across the board, both MAF and VE, that got everything where it should have been except my PE/WOT AFR. So you're right, I just need to pull a hair from my MAF Cal, and that ought to get me closer to my commanded. Have to remember what I do every step of the way!

I have my EQ Error and my MAF Error both set up, but I didn't think they'd be very effective since the car is back in open/closed stock ish settings. Those should be able to be seen in one of my original posts, i believe they are set up correct since they got me where I am now. Forced it Speed Density by failing the MAF and changing the few other things, disabled the LTFT in the scanner just to make sure they were not effecting it. Then did the same, forced it MAF only, and messed around with that. The MAF was difficult to hit the high Hz while remaining safe on the street. So that would explain what you mentioned, the 9k - 12k being out of whack.

Thanks a ton for the help, I will definitely pull a bit of fuel out of the top of the MAF and run around a bit to see if it gets closer. I am over all very happy with where its at, LEAPS and BOUNDS better than what the stock tune had. Wouldn't have thought just headers and an intake would have it adding 15-20% in the LTFTs pretty much across the board.

I was messing around with Virtual Dyno, and unfortunately I dont have any logs stock to compare it to, but just tinkering with it today, messing with the PE table a bit getting it a bit leaner at WOT, picked up ~20 HP on the same 2 stretches of road both ways......sure its not 100% reliable, but with my old MS6 it was always within a % or 2 compared to the actual dyno.

Either way, I am having a blast tuning this thing and learning about the computers.