Tuning and OBD Codes?

Morning All! Happy Monday!!

I realize that this might be academic given that we can turn off the codes, but the need to know is winning and I want to see if anyone can explain the causes before I simply turn them off!

I have what is typically the dreaded P0299 code. Underboost! That usually means the turbo waste-gate is dying. I just put in a Frankenturbo F23L, so I am pretty sure that my WG is fine and am turning to tuning. Since I have been driving it with this persistent fault, I have now gained a P0420 (yes, the "your turbo is smoked" joke crossed my mind!) which is a permanent version of the 299.

Since this is a VERY common error on these cars and the standard fix is to replace the turbo and add a tune (typically with the fault turned off), so there is little info to explain what causes the fault and how to properly correct it in the tune.

Does anyone have info on what the ECU is comparing to trip this fault? I cleared it while driving steady state (very low boost) on the freeway last night and it still returned within minutes, so I'm thinking it's at the lower end of my maps, but being relatively new to tuning this way and these ECUs I am not sure.

The car drives good otherwise. I'm still learning the tuning, but it's got no other bad habits except a little knock retard at the high end of the spectrum.

My thoughts on options:

• My WG is not tight enough and needs to be turned up. This isn't easy to adj, so it's not a fav option!
• The lower end of my Boost Duty map needs to be increased.
• Possible boost leak. (Already went here for another issue though!)
• a combo of 1&2?

Anyone got a clue as to what I am missing?

Thanks!

KS

Here's the current tune and last log for your review!

Attachment 100291

Attachment 100292

Thanks!

KS

to answer the underboost question fully we need to be logging boost actual vs boost requested and WGDC to see if there is any WGDC left in it and to see how far the deviation from requested the actual boost is.

since HP hasn't added these yet (I have a ticket open with them right now for it) the way i have dealt with this is just to raise the deviation allowed in ECM 34930 and in some instances the duration (ECM34931) but normally just the former is enough.

as for your P0420 code, you need to disable Catalyst diag in both ECM 2117 and ECM 45687 and ECM 45688

Hope this helps :)

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Originally Posted by TylerJDubbs

Hope this helps :)

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Yes sir!!! It sure does!

I saw the Deviation section but didn't know if changing that or trying to hunt down the actual cause was the best option. Changing the deviation would effect other areas but hunting it down might be near impossible for me!

So, I 'm going to log those 3 parameters and see if I can track down the split. I'll post up what I can figure out and see if you concur!

You don't think it's the physical waste-gate adjustment? It was high on my list, but really the last thing I want to adj. It's such a horrible place to put that thing! My hands still have scabs from trying to tighten the last manifold flange bolt in there!!

Thanks!!!

KS

When you get those logged post values to datazap and post link here. Link to chart b4 i adjusted crack pressure:

https://datazap.me/u/bb-tt/2020-05-0...data=1-7-22-23

You can see in the chart above 5800 rpm the waste gate was essentially closed.


If your wg crack pressure does need adjusted it is really not that difficult depending on which turbo you have. Does the franken turbo have a threaded rod?

I also have a ticket for same issue TJdub, downloaded newest beta the other day and i could now select them but when trying to log them they grayed out. So at least the "turbo folder" was added for the b8 and they are making progress. Hoping that i will be able to get a better sample rate with HPT than VCDS.

Quote:

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Originally Posted by bb-tt

When you get those logged post values to datazap and post link here. Link to chart b4 i adjusted crack pressure:

https://datazap.me/u/bb-tt/2020-05-0...data=1-7-22-23

You can see in the chart above 5800 rpm the waste gate was essentially closed.


If your wg crack pressure does need adjusted it is really not that difficult depending on which turbo you have. Does the franken turbo have a threaded rod?

I also have a ticket for same issue TJdub, downloaded newest beta the other day and i could now select them but when trying to log them they grayed out. So at least the "turbo folder" was added for the b8 and they are making progress. Hoping that i will be able to get a better sample rate with HPT than VCDS.

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Yes I was also lured into thinking they finally added them and then got the crushing blow of having them all grey out once I connected to the car lmfao

Quote:

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Originally Posted by TylerJDubbs

to answer the underboost question fully we need to be logging boost actual vs boost requested and WGDC to see if there is any WGDC left in it and to see how far the deviation from requested the actual boost is.

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Do you know how to fix the deviation if there isn't any WGDC left? Or if it even matters if there's a big underboost deviation?

I'm wondering if the strategy for adapting to a bigger turbo and/or different wastegate is to just mess with the wastegate controller to prevent boost spikes, or if one should really try to adjust the turbo compressor or flow maps (or whatever controls how much boost the ECU thinks it can get).

Quote:

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Originally Posted by bb-tt

I also have a ticket for same issue TJdub, downloaded newest beta the other day and i could now select them but when trying to log them they grayed out. So at least the "turbo folder" was added for the b8 and they are making progress. Hoping that i will be able to get a better sample rate with HPT than VCDS.

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Did you guys try removing all SAE PIDs and only logging non-SAE PIDs or vice versa? I believe HPT is working on a fix, but right now you can only log either all SAE PIDs or non-SAE PIDs, not a mix of both.