Magnuson PDB PE/BE

[ohsquigglyinmyeye]

Hey everyone, a buddy of mine had his truck tuned locally and while it seemed to make good power on the dyno, on the street it would just fall flat on its face in the mid-rang making it less than desirable for street-ability. He is currently working with a remote tuner which is taking some time as expected being in two different locations, but we were curious on the PE and BE settings and wondering if this is the culprit to the issues he has been having. Below is information on the truck and screenshots of the PE/BE and the VE table. I have cleaned up the VE table some, but after looking on multiple forums and sites it seems that PDB setups are not really talked about much in comparison to centrifugal or turbo setups.

From what I have been able to find, there are some debates on the PE/BE and which should have a lower AFR due to the setup being PDB and the 2 second delay on the BE. Any input would be greatly appreciated!

Thank you in advance for any input or guidance you can provide!

Truck Specs:
2004 Chevrolet Silverado ECSB 4x4
Factory 04 5.3L (LM7)
05+ radiator and e-fans
MP112 Magnuson s/c stock w/ 3.4? pulley and lid spacer to help with heat soak
Speed engineering 1 ?? long tube headers, x-pipe with full 3? inch exhaust
NGK TR6 plugs
K&N drop in filter
2 bar ON3 Map sensor. Tuner switched to 2 Bar MAP OS
FIC 60# flow matched injectors (no data sheet provided from TSP) Tuner adjusted
Performabuilt extreme 4x4 4L60e (rated for 450whp)
Circle D 300mm single disk billet converter with around 2000 stall
Truetrack rear with stock 3.73 gears
34.6? tall tires
aeromatic 340 fuel pump in factory return less system
93 octane








Capture5.PNG

R/
Chris

[07sgguy]

That VE table is funky. I'd imagine that might be a part of the problem. You mentioned they tuned it on the dyno, but did they tune it on the street?

Y'all need to do part throttle tuning cause there's no way the VE table should look like that.

As for the other things, I can't comment too seriously as I am an NA guy, but nothing stands out as much as the VE table under vacuum and low boost. How does it idle?

[ohsquigglyinmyeye]

Yeah its been smoothed out, originally it was extremely lean around 17-19 AFR driving around and under boost it would drop all the way down to an AFR of 9, and having knock all over the place.

I to am predominately an N/A guy so this is outside of what I am used to. But the original tuner just put it on the dyno at his shop and when issues arose with the tune, he dropped off.

He has been working with the remote tuner doing part throttle tuning up to 4500, but the last time the truck was running extremely lean and would fall on its face and after he made a change it was super rich and would fall on its face. Which is why i am wondering if its because of the PE/BE tables

Idle is pretty good, hangs around 14.4-14.8 range, not steady but

Below are the results of the last two tunes the truck had and the quick drive from earlier today, but that VE table is a lot closer now than what it was before


Capture SD 1.PNGCapture SD 2.PNGCapture SD 3.PNG

[Lakegoat]

I use 85kpa on Map enable. 1.27 on PE and BE. 0 delay, Ramp in 2.0. VE tables are all kind of shapes for different vehicles. At least it is smooth. You need to post the tune and a scan log.
Looks like you are on the right track. Just saw the above post.

[ohsquigglyinmyeye]

Attached is the most current tune and a log file from earlier this morning, thank you for your help!

R/
Chris

[Lakegoat]

Lots of knock in that log.
Is the linear and offset correct for that map sensor? They don't show it on the website. Is it mounted in the blower base? The 130kpa looks strange at 2500 rpm.

[ohsquigglyinmyeye]

Pretty much every log has had knock a lot of knock, so its been dropping down to the low octane table almost immediately. The more recent tuner who was working with my buddy said he was leaning towards false knock from the longtube headers on the truck, but the knock has been consistent when the truck is lean or when its rich

The linear and offset are correct! The MAP sensor is on the blower base close to the firewall. I saw the 130KPA range and just made an adjustment so it would not have that slight dip down there!


227532451_973454703499132_2698065376905316730_n.jpg

Previous log files shown in screenshots:

Lean Log
7.27.21 drive1.hpl7.27.21 drive2.hpl

Rich Log

7.29.21 drive1.hpl

[Lakegoat]

Here is an 04 base magnacharger tune/P59 computer. You can check the knock sensor and burst knock settings against yours.
On your latest tune, under engine diagnostics, DTC's--P0101,102, 103 are set to no mil light. That should be Mil on first error to get it in sd quicker.

[ohsquigglyinmyeye]

Thank you! looks like a decent amount of difference between the file you provided and this most recent one in regard to the knock sensors and burst knock. I am thinking the tuner set those to no mil because its a 2bar OS and while the MAF is currently there, my buddy has no intent on using it!

I was also able to track down the tune file and 1 log following it being on the dyno. Unfortunately the log was configured for a 1 bar MAP channel and not the 2 bar, so the results are not necessarily accurate. The issue he was having with this tune was similar to now with the mid-range but his truck would also constantly drop down to 400 RPMs when coming to a stop and try to stall out, as well as heavy lean and rich spots. When he reached out to the tuner to see if he could help, the tuner dropped off and stopped responding to him which led him to start looking for a second tuner

2004 Silverado Magnuson.hptPost IC fix drive 2 W AFR.hpl

R/
Chris

[Lakegoat]

Set the P0101,102,103 to MIL on First error. One of the steps in failing the MAF.
Go to spark---idle overspeed and make the last 5 cells -8.0
Go to idle, airflow--base running airflow and add some airflow in the 133 degree and up cells, add 2.0 and see how it reacts.
Your burst knock is turned off so that would not be the cause of the knock.

[ohsquigglyinmyeye]

Changed those DTCs to MIL on first error and burned to the truck with your suggested changes, i am going to try driving the truck this afternoon when I am on lunch!

R/
Chris

[Lakegoat]

I added one more reply above

[ohsquigglyinmyeye]

Got it! just made the changes and walking out now to burn it. Thank you again!

R/
Chris

[ohsquigglyinmyeye]

Results were similar with it bogging down pretty good in the mid-range and struggling to get up to speed. I also happened to notice that when it starts bogging down, his aftermarket IAT gauge drops down to 0 until you left off the pedal and a few moments let it will jump back up to the temperature it was at. I have not had a chance to take a look at this yet, but thought it was of interest and may be indicative of whatever issue he is having

8.4.1drive 1 MT.hpl

[Lakegoat]

The changes that I posted were not for the bogging. Just to get you on the right track to tune it and not have to go back and re do the tune because these were not done. The overspeed and base air were to try and help with the idle going too low, the dtc's to make sure the maf was failed.

[Lakegoat]

A big reason why it bogs is the knock when you get on it. It has negative timing, so it is not going to run very well. What is the plug gap? Should be .025. I would get rid of that map sensor and get a genuine GM 2 bar sensor , Linear 200.00, Offset 8.00 . Where is the IAT sensor located? Should be in the blower base, but your numbers are very low for a blower. I would also get a non projected tip plug like a NGK BR7EF.

[blindsquirrel]

Aftermarket IAT gauge? Um, is this contraption using it's own separate sensor or is it tied into the one the PCM is using?

[blindsquirrel]

Your wideband math is wrong somewhere. 'AEM EQ' looks like it is just doing AFR divided by 10.

[ohsquigglyinmyeye]

He said the plugs are gapped at .035 and I?ll let him know about the map sensor! The IAT is in the blower base below the snout on the driver side. I?ll see what kind of plugs he is running as well.

I think right now the aftermarket gauge is tapped into the same sensor that the PCM is reading. I will take a look at the wideband math just to make sure that it?s good!

Update:

He is running NGK TR6 plugs, gapped at .035. The IAT being used is one from Magnuson, and he spliced into the factory harness for the reading so he could hopefully visually see the same reading that the PCM was seeing. He also has a phenolic spacer on the blower to help keep the temps down, as well as a larger intercooler.

He went ahead and ordered a genuine GM 2 bar MAP and those plugs to see how it does!

[ohsquigglyinmyeye]

Had to look real quick to see which one you were talking about! The AEM EQ is set for when the gauge is changed over to Lambda, but currently we are using AFR for the readings and for the graphs its using AFR Error and not EQ Ratio Error.