Full Throttle Tuning Help

[Sprucegagt]

Well it finally took long enough but I have some scans here of a few WOT runs. All of these runs are with a gradual increase to full throttle. I tried to nail the throttle one time and found out my trans settings don't like it.

EDIT: These scan results are more messed up than I thought. Take a look at the O2 and commanded afr values. Any help would be appreciated.

[tejohnson]

Those O2 values just look plain scarry ;) Do you think it is accurate? Have you changed the way KR is implemented, or is recovered? May want to revert that back to stock... lol

Assume you have changed PE_Enable_TPS ? Looks like it is staying at 14.7 quite a ways up through the throttle percentage.

If not that route, folks seem to be a fan of adding AE. As an example, I add lots myself, but would rather attack this through VE since I go a bit overkill. See the attached export. ;)

Otherwise, make any changes recently? While AE is probably a quick fix, it is gonna dump the fuel, but should cure that positive ltft a lil in FT cell 3.

Do you feel it buggin out on ya at about 5k RPM?

[xonelith]

I haven't looked at them in too much detail, but it appears you are having the same problem with PE enable that I was having (delay).

Unless you don't have a MAF and are tuning SD, VE is useless as these tables are only used during a MAF failure (unless you have a V8:)). I assume Todd is not using a MAF.

Can you post the bin? We could probably help more if we see what you're workin' with.

Keep in mind I'm still learning. Todd is the man!

[tejohnson]

lol... I'm not the man. Everyone is still learning ;)

I do run a MAF. Moving to an LS6 MAF actually...

EDIT: I will say tho, I'm not sure addressing VE is a useless effort. One example is a problem I had going to meet up with Pat and Julian at the dyno last year. On a long drive, I put the car on cruise control. Since I had a modified MAF table (a lil excessive), the car would evaluate that the results from the MAF was insane due to the VE table, car would enter SD mode & start to stall, cruise control would add more gas, car shut down.

This is not fun while passing a large amount of traffic on the interstate going ummm... 70. Yeah. 70mph lol

[Sprucegagt]

To answer some questions.

Tejohnson:

1. Those O2 values have me very scared. The car did not bog at all though. So accuracy can come into play here. I changed the O2 about 30K miles ago. Stock GM replacement from GMPD.

2. I have not touched the KR tables one bit. They are completely stock.

3. PE enable table was set to 60%. The delay on this is puzzling me at the moment.

4. I'll say overkill! Multiply my values buy like 6 or 7 and they will start looking like yours. I have created a "starter" bin for my car. It contains a stock VE table. Once I make my EGR by pass plate. I plan to redo VE. Followed up with MAF adjustments. I thought the AE tables were more for flash or burst KR than anything else? Has that thinking changed?

5. I noticed the high LTFT in FTC 3 as well. I plan to include my TPS % with my regular VE tune parameters. I'll take the max. TPS value and use that value for my PE enable table. Plus make it the reallow point for AE as well. Maybe things will be different? I don't know. If not then I will attack it with AE next.



Xonelith:

1. MAF is definitely being used. Also I know from experience that adjusting the VE table makes a BIG difference in how your LTFT values react between Fuel Trim Cells. Also, the VE table is being used as sort of a sanity check on the MAF. If the MAF is to far out of line with the VE table, the car will revert to the VE table.

In searching around recently I found this NA tuning guide. It recommends doing a VE tune as well. I plan on following some of the information in this.

http://www.wnyym.com/newbie/tuning_new.htm

[xonelith]

Regarding the MAF debate. I changed all my values to zero to test the theory, and it made no effect on my driveability. Also, when my MAF did fail, the car ran like ass (meaning my VE table is way out). But, it definitely doesn't hurt to play with the values. IMO, unless there is something wrong with DHP, any changes you notice are due to other parameters (or mods, as in Todd's case where he does not have the stock MAF)

However, this year I plan to ditch the MAF (for sh1ts and giggles) and tune SD. I also plan to tune open loop entirely, for the sake of learning what all this stuff does..LOL



Also, Todd, you ARE the man:)

[Sprucegagt]

Regarding the MAF debate. I changed all my values to zero to test the theory, and it made no effect on my driveability. Also, when my MAF did fail, the car ran like ass (meaning my VE table is way out). But, it definitely doesn't hurt to play with the values. IMO, unless there is something wrong with DHP, any changes you notice are due to other parameters (or mods, as in Todd's case where he does not have the stock MAF)

However, this year I plan to ditch the MAF (for sh1ts and giggles) and tune SD. I also plan to tune open loop entirely, for the sake of learning what all this stuff does..LOL



Also, Todd, you ARE the man:)

Did the MAF fail when everything was set at 0? I believe VE tuning is very beneficial. I'll post scans of my car before the VE tune, after I made my changes to the VE table and after I plug the MAF back in and readjust the MAF table. I will be starting with a stock VE table, MAF table and 5% added to my AE table. That should provide what ever proof people need on whether it makes a difference or not.

Also I hope your not planning on running all the time without the MAF. I take it you know that if no MAF signal is present then the transmission will be placed in safe mode. That means full pressure shifts all the time.

[xonelith]

I'm going to force a MAF failure, and tune SD, not lose the connection (ie not pull the MAF out completely). There's some way to do this, I just can't recall off the top of my head exactly how to do it (to avoid the tranny safe mode). I've had a MAF failure before, and the tranny didn't go into safe mode.

I would be very interested in seeing your scans before and after the VE tune (can you fire the before and after bin too?).

DHP and HPT, in some cases, reference items differently, so we may be talking about 2 different settings. It has been confirmed to me, by someone who has direct access to the GM code, that the VE tables are not referenced unless the computer detects a MAF failure (or some kind of MAF inconsistency).

Most of this is what I've heard (and 1 test that I did when I first got my tuner), so take it fwiw. I could be completely off base. If adjusting your VE's is making your car run better, then don't listen to anything I have to say...LOL.