E38 T42 TM pulling timing randomly with trans as source

[GPGTP]

72 cutlass current tune.hpttm 3.hpl

This is for a 72 cutlass LS3 swapped with LSA blower and 4L60e trans. As you can see from the scan it pulls timing when driving. It seems very inconsistent and I'm not sure why it's happening. At one point it was doing it at idle in park. It also didn't do it for an entire run but then when I shifted into reverse and then back in gear it started doing it. The source says trans but I have everything adjusted that I can. I've never seen an issue like this running a 6L80e/ T43, so I'm assuming the E38/ T42 combo is the culprit. Reducing the VTT seems to help but then causes a P1516, I can open up the parameters for this so its not a big deal but still. I can probably get rid of it by further reducing the torque tables but I shouldn't have to. I'm wondering why this is happening in the first place. It's funny because it popped up while tuning after I REDUCED the MAF table because it was too rich. If anything I would think reducing the MAF table would help, but I digress. Any thoughts on this? If he just ran a 6L80e in the first place this probably wouldn't be an issue.

[Ben Charles]

Don’t delete all the tq management on trans side

[GPGTP]

Don?t delete all the tq management on trans side

Please elaborate if you would, I don't have all the torque management deleted. LOL that would be a death sentence to this trans. I can't believe they chose it for this combo in the first place.

[Alvin]

are you actually feeling this timing loss? I don't see antying out of the ordinary.. Time stamp?

[morepowerjoe]

I actually feel timing loss on mine and can't figure it out either.

https://forum.hptuners.com/showthrea...-for-no-reason

[GPGTP]

are you actually feeling this timing loss? I don't see antying out of the ordinary.. Time stamp?

Ben, are you saying I should make the torque management values more realistic? Maybe start from stock and bump them a tad. I have noticed these combos do weird stuff when you max them out. My truck is an 08 with this same controller combo and it does weird stuff when I do that. I've just never narrowed down exactly what causes it.

yessir, you can feel it, its definitely pulling it. You can see it all over the file but a good example is 1:02.

morepowerjoe: start with stock TM tables and bump them up if needed but only enough to make it any limiting go away. Problem for me is this car is an hour away and the customer wont leave it with me to try fixing it.

[morepowerjoe]

Ben, are you saying I should make the torque management values more realistic? Maybe start from stock and bump them a tad. I have noticed these combos do weird stuff when you max them out. My truck is an 08 with this same controller combo and it does weird stuff when I do that. I've just never narrowed down exactly what causes it.

yessir, you can feel it, its definitely pulling it. You can see it all over the file but a good example is 1:02.

morepowerjoe: start with stock TM tables and bump them up if needed but only enough to make it any limiting go away. Problem for me is this car is an hour away and the customer wont leave it with me to try fixing it.

But I have most of the TM tuned out. Are you saying that I need it on in stock from. Because I used to not have this problem I only noticed it after I had my exhaust changed and rescaled my maf. I'm starting to wonder if it has something to do with the virtual torque which I haven't touched?

[GHuggins]

But I have most of the TM tuned out. Are you saying that I need it on in stock from. Because I used to not have this problem I only noticed it after I had my exhaust changed and rescaled my maf. I'm starting to wonder if it has something to do with the virtual torque which I haven't touched?

Pretty sure yours is a different issue - did you ever fix the tcc slip problem?

Then if this started only after rescaling the MAF - did you lower the MAF? If you did then yes increase the "airmass" side of the torque model by roughly the same amount that you lowered the MAF by.

[morepowerjoe]

I haven't messed with the tcc slip just yet because I don't know if I truly have a problem with it. The truth is I forgot to save a as found file before I did the maf rescale. What exactly do you mean by lowering the maf are you talking about raising or lowering the fueling?

[GHuggins]

Well, you're not exactly raising or lowering fueling. You're raising and lowering air that the ecm uses to calculate fuel corrections. Basically the same thing, but nevertheless - did you lower or raise the MAF curve from what it was previously? If you lowered it then to get the same torque correction then the "airmass" tables need to be raised by roughly what you took out of the MAF. If you raised the MAF then you might possibly need to raise the "map" side to balance them back out.

Your whole issue in the log you posted on the other thread was a slipping tcc. At least from what I was seeing. All of your pressure apply tables are zeroed out - unique operating system that did that from factory - guess it's possible? Simple test - change the tcc settings to not apply in any gear - is the problem gone?

[morepowerjoe]

Thank you, I'll give it a try.