Converter lockup causing lag off the line?

[Dozerboy]

My truck is a dog off the line unless I over fuel the turbo more then I want to. I curious if the TC could be locking up too aggressively now that its ~12 years old?

Truck has a built trans, Danville 64mm stg2, 100over, 12mm stroker, studs, lift pump, and my tuning.

I feel I have a pretty good grasp of tuning. The truck has always ran great. Added the turbo and noticed a little more lag. I think I logged 0.2 second more lag to full boost after retuning for the turbo. Added the 12mm and everything was still good. Once I did the studs(HGs) and injectiors things changed it seemed. Maybe part of the problem is my expectations changed aswell. I don't want my truck to be the smoky pig now. Compared to not really carrying before. Now I have to over fuel pretty good to get it responsiveness I think I should have or even that a stock truck has. If I only fuel it so its a bit of a haze its a dog. Fundamentally, my understanding is low timing and higher fuel pressure will create boost the fastest. I have played alot with the tuning vane position, fuel pressure, and timing. Going to extremes both high and low. Even focused on seeing how to reduce lag as much as possible locked up in 5th, 1500RPMs, and apply that to off the line lag. Probably 100s of tunes and logs.

I'll post a picture of the components to my transmissioinand a screenshot of my log from a dead stop no power braking. You can see where I highlighted the log. There is no increase in fueling or anything, and the converter is locking up very quickly. That is the area i'm trying to address.

 

[PureHybrid]

Hmm, I would have to ride in it or see a video, but from the log it looks like the converter is way too tight simply based off of engine rpm and tps. The area you have highlighted it's not even coming up to 1800rpm. And I'm not sure what the tcc slip is doing. Possible the stator is broke?

 

[Dozerboy]

Hmm, I would have to ride in it or see a video, but from the log it looks like the converter is way too tight simply based off of engine rpm and tps. The area you have highlighted it's not even coming up to 1800rpm. And I'm not sure what the tcc slip is doing. Possible the stator is broke?

I have slip logged. Bottom left in yellow.

What would you want to see in the video? Dash with RPM etc or out the window for smoke?

 

[PureHybrid]

Just rpm on the dash so I could hear it to verify what I'm seeing. It doesn't make sense...

TPS 100%, the TCC slip gets pulled down a bunch, mm3 drops all before it should even be out of first gear?

 

[JoshH]

Why does your MAP show 12.5 psi at tip in? I thought you were down around Houston. It should be closer to 14.5 there.

 

[Dozerboy]

Just rpm on the dash so I could hear it to verify what I'm seeing. It doesn't make sense...

TPS 100%, the TCC slip gets pulled down a bunch, mm3 drops all before it should even be out of first gear?

I've always had a quick fuel spike at the beginning then it drop and start to rise again. Lambda starts a 0 in my tune and quickly goes up to 1.6 or so off the top of my head.

 

[Dozerboy]

Why does your MAP show 12.5 psi at tip in? I thought you were down around Houston. It should be closer to 14.5 there.

Yes Im in Houston. I thought 13 would be normal so never questioned it. I'll have to look at old logs to see what it's read in the past. I'm pretty sure I've never rescaled the MAP or anything.

 

[JoshH]

We're at about 500' elevation here and see right at 14.4-14.5 psi for barometric pressure. I would imagine Houston is the same if not a little higher since, I assume, it is closer to sea level. I'm wondering if you have some sort of restriction causing MAP to be reading too low off boost. If you turn the key on with the engine off, what does MAP show?

 

[2004LB7]

Google says 90' elevation above sea level is the highest within the city of Houston. And 50' is average

 

[MarkBroviak]

Why does your MAP show 12.5 psi at tip in? I thought you were down around Houston. It should be closer to 14.5 there.

I think it is the wrong pid, I see it a lot. He needs to log map2 to get the correct reading.

 

[Dozerboy]

Just rpm on the dash so I could hear it to verify what I'm seeing. It doesn't make sense...

TPS 100%, the TCC slip gets pulled down a bunch, mm3 drops all before it should even be out of first gear?

Source: https://youtu.be/V1L7pP8x9q8?si=hIEtION6sVFek7mw

 

[Dozerboy]

I think it is the wrong pid, I see it a lot. He needs to log map2 to get the correct reading.

Thanks Mark that makes sense.

Edit I looked at a log I took of a friend's truck and he idles at 12.9

With just the key on and no air filter there was no difference in the reading. The barometer PID is reading right. Not sure where the ECM gets that data.

 

[PureHybrid]

Source: https://youtu.be/V1L7pP8x9q8?si=hIEtION6sVFek7mw

Well you weren't lying, it's a slug haha. Sorry I had to. Honestly I'm not sure how to steer you in the right direction with the tune, but I'm sure a different converter would help a ton. Is that a fairly smoke free tune?

 

[Dozerboy]

Well you weren't lying, it's a slug haha. Sorry I had to. Honestly I'm not sure how to steer you in the right direction with the tune, but I'm sure a different converter would help a ton. Is that a fairly smoke free tune?

Yes that's just a little haze. If I lower the Lambda much it gets smokey.

Here is my Lambda table and a log of a friend's stock(we think) LBZ. It goes from 2-12mph maybe as much as 0.2 sec faster and to 30mph almost 0.9 sec faster then my truck.

 

[Chevy1925]

Boost leak tested it?

 

[2004LB7]

look like your MAF lbs/min is a little slow to come up. but I'd have to compare it to some of my logs. how's your boost? don't see it in the log

 

[2004LB7]

and maybe log current gear also

 

[Dozerboy]

Boost leak tested it?

Yes I have to 25psi with soap and water. No leaks.

 

[JoshH]

Now that I know you don't have a major restriction in the system (thanks Mark), I'll say two things:

1. Your converter seems to be way too tight. Aftermarket turbos, even VGT, need RPM to spool.

2. I know others have had a different experience than me, but I've never had any luck getting turbos to spool by lowering timing. I've always had the best luck cleaning up smoke and making trucks responsive by adding more timing.

 

[Dozerboy]

look like your MAF lbs/min is a little slow to come up. but I'd have to compare it to some of my logs. how's your boost? don't see it in the log

I don't log boost just MAP and MAF. I control boost with the vanes. I make 35psi+ on my mechanical gauge with 16% vanes at. It has a recall button and has spiked to 40psi. That's a 700hp tune(my guess). 20%-16% vane 3200rpm-3400rpm, 1650us 100overs, 20* timing .

Here is gear and Torque converter clutch duty cycle added into that same log. Bottom right.

Well picture won't attach that area in question 1st gear and 0% Torque converter clutch duty cycle