VE tuning 6.0 Turbo

[kunta0908]

2006 C6 w/iron block LY6
BTR Stage 2 turbo cam
1050x ID injectors
CX racing hot/cold side
88mm On3 turbo
2 bar Map on 2bar OS
Open loop SD tuning


In the process of dialing in my VE tables and get timing correct before jumping in and installing my flex fuel sensor.
Running an AEM 03-0300 wideband through the MPVI input. Cruise is starting to come together, but obviously getting into boost I am running into issues. Looks like a bad lean tip in as well as a not finely tuned VE table.

Anyone notice anything else that I might be doing incorrectly? Or am I on the right track and just need to make some more pulls and keep finely tuning the boost areas of the VE table (as well as some more work on the cruise).

I used bits and pieces of repository tunes to get started, timing tables as far as I know, are low and on the safe side while figuring the rest out.

Included is my tune file as well as a scan from today, a pull onto the highway at the start of the scan, and a short pull at the very end of the scan as well.

[kunta0908]

One quick question to add.

In the boost regions, should I be tuning with the average of the cell hits, the very negative, or the highest? As of now I have been tuning off of average % error in each cell. But looking at this recent log, I hit 8 degrees of KR in the first pull when the average showed -2.9% or somewhere close. Actual lambda was nearly .63 on a commanded .75. So that -2.9% was nowhere near where I was on that pull.

I know that more and more data will get me a better % to tune off of, so is it going to be small changes like that -2.9% every time till I start seeing good results? I would really like to avoid throwing any KR at the motor, let alone spikes upwards of 8. And why is there such a variance (-12% one time through the cell and +9% at a different time through the cell).

[5FDP]

How long are you data logs that you are doing?

When you take your lambda error and apply it to your VE tables are you always pasting by % or do you paste special % by half?

If the numbers are kinda large just do it by half to slowly work the table. Use the smooth functions to remove spikes/dips. Get long data logs for cruising, like 15-25min at least. Also do not max out your knock retard decay tables, you do not a table top wave form for knock. It's yanking out timing as fast at possible then slamming it right back in when it goes away, then it knocks and yanks it all away again. Try making them slightly less sensitive, with your mods it's possible part of it is false knock.

Side note, 2006 won't have the desoot mode that often times could cause the lean spikes once PE is enable.

[kunta0908]

My knock retard decay tables are at 50.0 (0-256 boundaries) across the board. I believe that was also something I yanked from a donor boosted tune.

[kunta0908]

I wouldn't be surprised if I was seeing some sort of false knock. The engine bay is a bit cluttered with this turbo setup, I think my downpipe might be a tad close to the lower radiator support.

[RySmDPT14]

i was getting false knock with my turbo set up, i found that the flex pipe i used was caused turbulence and would resonate so bad i was seeing knock as high as 10 degrees. I straight piped the crossover taking out the flex joint with better results.

[kunta0908]

How did you come to determine trhat the flex pipe was the culprit? I have two flex sections running horizontally in front of the motor, merging into the turbo. I'd be at a loss as to determine whether they were necessary or not.

[RySmDPT14]

I kept getting knock at 2900 RPM's, I brought down spark added fuel etc and my buddy actually noticed the vibration resonance through the floor boards. The only culprit I could determine was the flex joint, so I cut it out and slipped a new pipe over it, the vibration is gone and I no longer get knock at 2900 RPMs and much better throttle response. I am lucky because I installed v bands on my crossover so its literally 2 min to take it out and put it on the welding table oh and I have a 10" lift so no crawling on the ground.

[SultanHassanMasTuning]

1stflex1122_MAS.hpt


maf was not failed properly

spark was a bit aggressive for feeling out your car.

this should help

[kunta0908]

Thanks a lot Sultan. I made the changes that I saw you make and fixed the MAF erroring as well.

Took it out this evening and it feels 100x better. Transitions from cruise to boost are much smoother and I don't get the weird stutter I'd usually get going from vacuum into boost. KR is nearly non-existent, and the partial/1 degree I did get at a couple areas, I went ahead and subtracted from those cells.

Now, I'm battling an issue at the top of 2nd gear, as I shift into 3rd, my car will throw a reduced power code. This is at around 14lbs and zero KR. But as soon as I let off the gas to shift, I go into limp mode till I reset the code. 3rd gear pulls will not do this. I've read about 102mm Tbs causing this, but I am still on my stock TB.
Could it still be the plate slamming shut as I let off the gas that is causing this?

[SultanHassanMasTuning]

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