APR Stg3 data logs... can someone help interpret?

[BigFat]

Hello,

My wife has a Stage 3 Avant that has been feeling slower than usual. There's a fluttering sound present on acceleration that I'm trying to trace.

We did some data logging last night, I'm hoping someone can take a look and comment on how things look? Pulls were done in 3rd gear from 1500.

Is there a way I can attach the spreadsheet to this post?

Thanks!

[p0isin]

Can you upload to Google docs and provide a link? If so, I can review them later on for you.

[p0isin]

Or you can click 'Reply' then 'Go Advanced' and then upload an attachment.

[BigFat]

Thanks! Here's the link... https://docs.google.com/spreadsheets...it?usp=sharing

[jbain2]

Your boost requested is not being met. The actual boost for both runs fell short. This is causing your lambda values to be less than stoich (1). You are running rich because you have undetonated fuel related to wrong air fuel mixture. I would start with a system pressure test or smoke test. I would also look at your MAF if you can't find a boost leak with the pressure test.

[p0isin]

On mobile but here are my thoughts:

You are running super rich from 4500 rpm to redline. You shouldn't see below about 0.8 lambda. Requested boost is not met even with 100% closed waste gate.

This most likely is due to a boost leak (I agree with the above poster).

Low and high pressure fuel systems seem fine. What MAF values do you normally see and what are they at now with the (supposed) leak?

[BigFat]

Thanks for the help so far guys. Really appreciate it.

Here is a link to a spreadsheet showing the MAF readings we logged: https://docs.google.com/spreadsheets...it?usp=sharing

[aluthman]

I agree with the above except that those lambda values are right about what I would expect from a conservative tuner like APR. 0.76-0.78 target lambda at WOT is pretty common for most other OTS tunes. Even with a boost leak, the ECU calculates fueling in real time based on the readings from the O2 sensor. This is one huge benefit of having a wideband sensor from the factory. The car will pull or add fuel via fuel trims to keep lambda at or near the target value.

[jbain2]

I agree with the above except that those lambda values are right about what I would expect from a conservative tuner like APR. 0.76-0.78 target lambda at WOT is pretty common for most other OTS tunes. Even with a boost leak, the ECU calculates fueling in real time based on the readings from the O2 sensor. This is one huge benefit of having a wideband sensor from the factory. The car will pull or add fuel via fuel trims to keep lambda at or near the target value.

Agreed that in most circumstances an OTS tune will run on the rich side, but that seems excessive. The numbers should certainly be verifiable with APR. He still has boost issues. I think fix that and make sure the fuel trims correlate.

[aluthman]

He does indeed have boost issues.

[BigFat]

Well, car has been at the shop for a few days - first off, I'm an idiot... we had the car worked on previously and unbeknownst to me, the battery was disconnected. I'm pretty sure this means the car was in "stock" mode, not 91 octane.

We had the N75 valve replaced as well as the diverter valve. Apparently the diverter valve was practically non-functional ... "it would work once, then stick, then not work anymore"

I haven't gotten the car back but I've been told it's making more power - turbo isn't spooling up until 4500rpm, and I'm not sure if that's the design of the turbo, or an indication something is still wrong.

We'll pick up the car tomorrow and I'll try to get some more logs done then to see where we are at.

Thanks for the advice so far!

[jbain2]

If your N75 or DV were bad, I would have expected to see corresponding codes indicating as such. I thought in your original post, you mentioned it was an APR kit, but I don't see that now. At any rate, I would think any "stage 3" kit, would consist of a turbo that "spools" sooner than 4500 rpm. Not sure what this means by the way.

Post up VCDS codes and logs when you get it back. Sorry you are stuck with 91 octane.

[krewbrew]

The logs show the tune calling for 20 psi (2,400 mbar), so it does not appear to be in stock mode. I looked at logs from my JHM stage 1 tune and show lambda values going down to 0.76 at 6,000 rpm, so the values in OP's log seem normal.

[aluthman]

The logs show the tune calling for 20 psi (2,400 mbar), so it does not appear to be in stock mode. I looked at logs from my JHM stage 1 tune and show lambda values going down to 0.76 at 6,000 rpm, so the values in OP's log seem normal.

I knew I wasn't smoking crack...

[BigFat]

If your N75 or DV were bad, I would have expected to see corresponding codes indicating as such. I thought in your original post, you mentioned it was an APR kit, but I don't see that now. At any rate, I would think any "stage 3" kit, would consist of a turbo that "spools" sooner than 4500 rpm. Not sure what this means by the way.

Post up VCDS codes and logs when you get it back. Sorry you are stuck with 91 octane.

It's an APR Stage 3 kit - GT2871R turbo.

I'm kinda pissed... we're over $1800 into repairs on this thing. We picked it up this morning and the noise is worse than ever - as in, I can hear the noise following the Avant in my own car.

Poor choice of words talking about "spooling" - what I meant was, I understood the turbo would be making full boost about 3500rpm, not 4500rpm. But maybe I'm off on that.

Don't feel bad about the 91. We've got 93 and 100 octane programs along with a water meth kit installed. Its just that 91 is the most common octane in my town, so we don't often fill up with anything higher.

I'm gonna get some more logs done soon, but honestly, at this point I'm concerned about actually driving the thing.

[BigFat]

Here's a video of the ticking noise:



Here's what's odd - hear how the ticking disappears around 18 seconds and then comes back? That's me pressing the ECON button (turning off A/C) then turning back on.

However, the car will still make this noise while driving, with the A/C on OR off. Also the noise isn't always present - when we were doing the logs, the noise wasn't there... when we drove back into town, we started hearing it again.

Just formatting the logs now... will update shortly.

[BigFat]

Boost & Fueling, 2nd gear pull:
https://docs.google.com/spreadsheets...it?usp=sharing

Boost & Fueling, 3rd gear pull:
https://docs.google.com/spreadsheets...it?usp=sharing

[baldy]

Have you checked the PCV? When it fails, the car is lethargic...

In regards to the ticking, is it coming from the front or the rear of the engine?
If the rear, probably the vacuum pump fitting.
If the front, probably the PCV in the metal pipe going to the turbo inlet (that is if the APR has that...not sure...)or the belt tensioner.
Could also be the timing belt tensioner.

Did you check block 90/93 for cam correlation?

[BigFat]

Have you checked the PCV? When it fails, the car is lethargic...

In regards to the ticking, is it coming from the front or the rear of the engine?
If the rear, probably the vacuum pump fitting.
If the front, probably the PCV in the metal pipe going to the turbo inlet (that is if the APR has that...not sure...)or the belt tensioner.
Could also be the timing belt tensioner.

Did you check block 90/93 for cam correlation?

Shop checked PCV, they said it was ok.

Noise is coming mainly from the front, but now that I think of it, there might be some noise from the rear.

Timing belt was replaced when we bought the car... 30,000 kilometers ago...

Did not check block 90/93 - what's the procedure for that?

[BigFat]

Played around in VAGCOM tonight... not sure I did it correctly, but intake cam correlation is spot on for requested/actual... at idle at least.

[BigFat]

Had it at a new shop, they found a blown gasket (either head to manifold or turbo to manifold, I haven't verified)... the "jet engine" noise we were hearing is gone - I'm wondering if that would account for the odd boost values in VAGCOM.

Anyway, test driving the car, the shop heard a noise on deceleration (only, not acceleration) that they think might be a rod bearing. Thinking about having them investigate, but that's quite a bit of extra work for something that's uncertain. :(

[BigFat]

Shop has opened up the motor. All rod bearings are trashed and there is a "suspicious amount of play" in the wrist pins... :(

[jbain2]

No Bueno! Time for some upgraded rods and new bearings so that you can really use that gt28 turbo. Will be doing the same thing shortly. Running the same turbo.


Sent from my iPhone using Tapatalk

[BigFat]

Agreed. Trying to make the best of it - motor already had IE rods so I'm not sure why this happened.

[BigFat]

Shop is now saying the car needs a motor. Two rods are trashed, scoring on cylinder wall #1.

I'm really hesitant to put in a scrapyard motor though - we'd have to do the timing belt again, transfer the H2Sport Fuel Pump Upgrade and all the jazz that goes along with it... seems like a lot of work.

Thoughts?

[p0isin]

Can you use bigger diameter pistons and bore out each cylinder .5mm? Might be able to save your motor

[BigFat]

So for anyone still following this saga, the car is still at the shop having the motor rebuilt.

Official answer from the shop as to what caused the damage - two failed oil squirters.

I'm under the impression that these squirters don't fail - so I'm not sure what caused these ones to go out, but there you have it.