VVE Questions

[Supercharged111]

I may end up making a thread pertaining to the whole car rather than just the VVE, but here goes: I'm working on a 2009 CTSV with a 9.X" lower pulley, 2.5X" upper pulley, long tubes, FIC 850cc injectors, reinfocred brick, and upgraded intercooler HX. With just the pulleys the car did OK for driveability (though it still badly needed a tune), but had wicked IATs as soon as I hooked up the laptop so we did the HX and the car was able to be looked at. Last night we got the AEM talking to EFILive and by that time, my laptop battery down down to a half tank. We went for a drive and I tried hitting as many of the cruise cells as I could. Low boost PE looked good but when I whacked it harder it was pretty lean. I cracked on it briefly twice and took those values (along with the cruise stuff), generated coefficients zone edge align set to 1, then generated VVE. When I copy/pasted with multiply the BENs into the VVE table I had some significant spikes but after generating VVE they were significantly flattened and blended. By this time, the laptop was about dead so I laid into it and it hung in the 12s the first go, but once the car hit 3rd it jumped to the 13s so at that point the goal was just to get home and do another flash with those BENs to rough it in a little closer. I'll admit they felt like dirty flashes, I didn't filter by cell count and didn't hit as many of the cells as I wanted to but the MAP has 2kpa increments so admittedly it's more difficult than working with GenIII stuff. The fact that this car was so damn far off in the first place had me feeling a little better about doing it this way, especially after seeing the extent of blending that occurred when generating VVE. How terrible of an approach is this? I figure after a few more flashes the spikes are going to be smaller and everything is going to find its way where it needs to be. Is this true, or should I go back to the stock VVE map and approach it from a different angle? I can post tunes and logs when I get home. He's coming over today and we'll have enough time to grab one good log and flash the thing before he has to go. One thing that struck me as odd is that with stock VVE it cruised in the 14s, and after flashing it cruised in the 13s. I have to wonder if this isn't from generate VVE blending a little farther from a spike that it needed to? I wonder if a couple more flashes wouldn't clear this up? The car is driving better than it did closed loop stock VVE, but admittedly open loop stock VVE was a huge improvement in driveability too.

[Supercharged111]

Today was encouraging. I think a better way to approach this would have been to bump VE globally 10% or so and I just might restart it all and do that. The BENs were much smaller today than yesterday and we saw 13s and 14s cruising as opposed to 12s and 13s yesterday. Here's the tune I started with today.

23382

Only thing I'd changed since yesterday was bumping the airflow reporting table 10% which helped a lot with the shifts and PE raped the thing in an effort to try and get BEN data for a full WOT pull. That didn't pan out, check out this lean spike.

23383

Here's the area of the VVE map where it occurs, no sudden changes here so I'm not too sure what to chalk it up to.

23384

Here's the log.

23385

I forgot to include fuel pressure in the log screenshot, but it was holding at 70 psi when it suddenly decided to go lean. Here's the tune I flashed and sent him home with.

23386

He cracked on it one time and it went lean on the way home, the rest was pretty good. I'm not convinced VE is the problem here but I could be full of it. I wonder if I'm hitting an airflow limit of some sort somewhere? I pulled his PE rape out under 5000 as it was tracking closely to what was being commanded there and added more in though it's really just a drop in the bucket compared to how lean it goes. I couldn't find a maximum enrichment factor either so not sure if I'm going to hit that limit too.

[statesman]

That didn't pan out, check out this lean spike.

On that screenshot, your commanded AFR jumps to 14.47.... not a good thing to happen when you're in boost.

[Supercharged111]

Whoa! It sure does, like it's commanding itself out of PE mode. Sure would be nice if I could download EFILive at work. My reaction time sucked, 1.1 seconds.

[nonnieselman]

So did adding 10% to the whole VVE table help you any?

I just found a stock CTS-V tune (E67) with a LSA and comparing it to this truck I'm working with that has a LSA (E38)

Finished a kennel bell 4.6 4V tune last night with a holley dominator and man I do miss after market ECUs....

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[ProperTuningOG]

One thing, for SD you can't have MAF set to not reported. First Trip no MIL and it HAS TO BE unplugged or wire pulled, preferably at the ECM. You have to have the MAF faulted to run SD. You are also showing an ACTIVE Misfiire code as well as CAT. All things that will mess with fueling. I'd also work on your spark tables..... You are also commanding a PE of 0.68.....

[Supercharged111]

I set up the MAF stuff per Swingtan's guide.

http://download.efilive.com/Tutorials/PDF/Virtual%20VE%20Adjustment%20Tutorial.pdf

I know it said I might need to physically disable the MAF by removing a wire at the plug. I forgot to validate that the MAF is actually failing, what are my indicators there? The misfire code is from the ECM commanding itself out of PE mode. As soon as that happens I get the flashing MIL. I had him pull plugs and we have a lean one, so wondering if an injector is sticking. We'd pulled them all, left them connected to the rail, and turned the key on and none dripped. I agree the spark tables need work but I wanted fueling right first. I commanded .68 because of how lean the thing was getting in an attempt to get the car to safely provide some BEN values so that I could apply those and command a more sane amount of fuel. By the looks of things, I will not need to be so extreme with the PE fueling if I can keep it in PE mode. I just spent the weekend at the track (not with this car) and hope to have a closer look when I get home.

[Supercharged111]

So did adding 10% to the whole VVE table help you any?

I just found a stock CTS-V tune (E67) with a LSA and comparing it to this truck I'm working with that has a LSA (E38)

Finished a kennel bell 4.6 4V tune last night with a holley dominator and man I do miss after market ECUs....

Sent from my SAMSUNG-SM-G870A using Tapatalk

Haven't gone back to try it yet.

[nonnieselman]

I added 20% to VVE and 25% to MAF with no change to AFR in boost on this LSA. So I have given up and got some professional help.

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[Supercharged111]

I added 20% to VVE and 25% to MAF with no change to AFR in boost on this LSA. So I have given up and got some professional help.

Sent from my SAMSUNG-SM-G870A using Tapatalk

Weird. This thing was responding to changes in VVE even WOT, though TP never reaches 100%. The showstopper right now is it kicking itself out of PE mode. I hope to get with him again this week after work and in the meantime wear out google and the search function.

[joecar]

I added 20% to VVE and 25% to MAF with no change to AFR in boost on this LSA. So I have given up and got some professional help.

Sent from my SAMSUNG-SM-G870A using TapatalkPost logs and tune files, and some pics of what you did.

[izaks]

Log GM.APP if you want to see 0 - 100% TP
and GM.THRA_A if you want to see what the TB is doing