5.3 Silverado... Newbie Tuning questions

[WantonNegLect]

2012 5.3 Silverado 6L80E with slightly larger lift and duration cam, nothing crazy. Wouldn't even call it a mild cam. Couldn't find a cam to keep VVT so that is gone as well. Just interested in using this truck as a DD, work truck, light towing (car on trailer, etc). As mentioned, this truck has been sitting for almost 3 years because I've just been very much intimidated by the tuning process. But I'm not about to give up. I've tried off/on watching vids, searching forums but so much of it is just a bit over my head. I need basics.

Is there a sticky or a thread that already exists that is for total newbies, just doing a simple tune after a cam change? Haven't been able to find what I'm looking for (part of the problem is, I don't know what I need to look for), I'm just gonna ask it directly here now.

Disclaimer... Most of the knowledge I possess about HPTuners comes from watching Goat Rope Garage Tuner series on YouTube. The specific video I am referring to is ------------MAF Tuning and Scaling, Tuning Series Vol. 3, HP Tuners---------------

1. Why do I need to tune the MAF? My MAF, intake and intake ducting is still stock. I would assume the MAF curve will still be the same despite changing cam.

2. I am a little confused about Open and Closed loop. As I understand it (correct me if I'm wrong...), Open loop goes off things like Coolant Temp, Intake Temp, and things like Idle base and startup tables. Not sure which tables are used when driving and still in open loop. Closed loop relies more on the narrowband sensor for fueling (but there must be more to it)?

3. The reason I am confused about #2 is because in the Goat Rope Garage video, he disables Closed loop by going to (Engine - Fuel - Oxygen Sensors - monitoring - O2 readiness - (-1.795 mV)). Adds a negative to the value, and has the closed loop status being logged as YES/active and he is in Closed loop for MAF tuning. He is using a wideband. This is confusing as hell to me. Care to elaborate on what's going on here? Also, I do not have that O2 readiness value, so not quite sure how to disable this.

4. The Engine - Fuel - Oxygen Sensor tab is also confusing to me. There's O2 use in open loop mode and closed loop mode. I suspect answering #2 and #3 will help answer this question

5. What triggers the changeover from Open to Closed loop?

6. When is MAF used? 0-4K RPM in closed loop mode?

7. When is SD used? Above 4K RPM in closed loop mode?

8. How do I figure out which PCM I have?

9. I need a general overview of the tuning process in my situation so I know what steps to take. MAF tuning, SD tuning, undo some disable stuff, put narrowband back on. Truck will be fine for DD and TOWING????????

Feel free to add info about SD tuning, although I can ask later after all this is answered.


Things I have done so far to the tune to be able to run off the MAF to make sure fueling is correct (Ballenger AFR 500 v2 Wideband)
1. Turned DoD off
2. Turned DFCO off
3. Turned CoT off
4. Turned VVT off
5. Disable SD tune???? via Engine - Airflow - Dynamic - High RPM disable 100 - High RPM reenable 99

Ok, that was the simple stuff.

Things not done yet in the tune
1. Enrich Fuel in the fuel table by say, 5% to ensure not running lean
2. subtract say, 3 degrees in spark base timing
3. What else?

I understand I'm asking a lot. If there is a good newbie learning library, go ahead and point me to that as well.

Thanks All

[WantonNegLect]

Ah, I'll need to disable some DTCs as well. Gonna look into that

[horsepowerguru]

more than likely you have an E38 pcm. OL also uses the HEGOs but it has no power to change the fuel trims, whereas CL is an average of the OL readings and IS able to adjust fuel trims based on what it sees. Change over from OL to CL is mainly determined when a certain ECT reading is reached, but there are other factors. If you have Dynmaic Air enabled then there is a mixture of the VVE table and the MAF table up to 4k rpm. after that it uses MAF readings. SD mode is disabling the MAF in the tune settings and running on only the VVE table. MAF only tune is disabling the VVE table to run on only the MAF sensor, which is usually done by changing when the MAF takes over in DYN air and what the maf High fail Freq is set to. in my personal experience i get better low end and mid throttle range (basically everything thats not WOT) results if i tune with STFT. I use a WB for WOT and PE...Also, i find forums and books more informative and more accurate than most things ive seen on you tube, just saying...hope this helps you some...

[WantonNegLect]

Ok, went back and watched some HP Tuners Live Training videos, which was very informative. I have a better understanding now. Also, ordered a Greg Banish book "advanced tuning" but it hasn't arrived yet.



So, the plan is to disable the MAF, disable narrowband O2s (THEY ARE REMOVED At the moment), and drive the truck to correct the VVE table (SD tuning) using a single wideband. Reason being, if MAF ever fails, use SD as backup. Sounds logical. After SD tuning is done, monitor some PE runs. Then put re-enable MAF and re-install narrowband sensors and put another 200k on the truck (may do road tuning only or pay up for load dyno, not sure if that is necessary. Opinions for such a small cam change?)


Items I have accomplished/learned/have a good understanding of:
1. Wired up AFR500 v.2 wideband to power/ground and to prolink (0-5V analog signal)
2. Removed pre cat narrowbands and installed wideband/plugged other open hole.
3. Keep the MAP value below 55kPa to avoid triggering PE mode
4. Failed MAF and set to report on first error in MIL, also changed MAF count threshold




Items I have questions about:
1. Getting the VCM scanner to correctly interpret the analog output for the lambda values (the math portion in scanner, I know the equation provided by Ballenger which is Lambda = 0.618 + Vout x 0.096 ). Still have a red box on my graph label "MPVI2.1". What am I doing wrong?

2. Could not find a VE table, only a VVE table. Is this is the correct table to modify for my truck in SD tuning?

3. Need to disable narrowband O2 operation in Editor. Not sure on the best way to do this.

4. Am I putting my catalytic converters in danger with the CoT turned off (which obviously I have to do to get the correct fueling)? What should I avoid doing to minimize the chance of damaging the catalytic converters?

5. I don't understand the "EQ ratio Based" table under Engine > Torque Model > General. On a related note, trying to figure out what is needed in terms of Channel output "commanded EQ ratio" in the VCM scanner. Do I want to set it to 1 always (since avoiding Power Enrichment for this tuning session) or is this the table it wants to follow?

6. Wideband sensor location. 2012 silverado has catalytic converters about a foot from the manifold collector. The 02 bung is in bettween this. Sensor mfg NTK wideband calls for wideband being placed 1-3 ft from exhaust but this isn't really possible without relocating the cats, so is this going to cause bad readings?

7. Still a little iffy on open and closed loop, but as I understand it, we are trying to keep it in Open Loop and run directly off MAP prediction tables (SD tuning), monitor wideband output, and adjust VVE table (DO NOT TRIGGER PE AND DISABLE ANYTHING THAT COULD SKEW LAMBDA READINGS)



I am attaching my stock tune file, my modified tune file (so you can use the compare function to quickly find my changes), and my VCM scanner layout file.

Let me know if I missed anything (O2 sensor disable and anything else), what else I should add in VCM scanner and whether I'm ready to rock

[horsepowerguru427]

after you add the channel in then right click it and use the transform feature. if you have a decent brand itll already have everything you need. if not youll have to use that math formula you brought up. gen 4s dont have a VE table, just a VVE which likes to change things when you calculate coefficients if you dont make changes correctly. I wouldve tuned a small cam with the fuel trims and NB O2 then installed the WB to verify and tune WOT and PE. I dont bleieve you ever stated your cam specs either?

[morepowerjoe]

Ok a few things. First off closed loop is how you want to tune the maf with the narrow bands except wot you tune with the wideband in closed loop as well. Closed loop is when your o2 sensors are directly controlling your fueling and open loop is when your ecm is putting in a preset amount of fuel based on your settings in the tune. All you have to do is log your stft with the scanner and the narrow bands. You take that data, copy and paste into your maf in the editor multiply by half. You'll want to have it set in a maf tune only to tune your maf as well. As for vve tuning (speed density) I'm not an expert on that so someone else will have to help you with that. So, I'm going to post my tune to help you set up a maf only tune. All you have to really change is the ltft (don't change anything else from the stock values) to what mine are under fuel and oxygen sensor settings and that should get a maf only tune going. Also almost everything with these settings will be a stock value. And after you get the maf stuff down with the narrow bands then you can attempt to do your wot tuning, more on that later.

Camaro Tune with new vve and old tune.hpt

[morepowerjoe]

Make sure you refresh the page to see my edits. lol

[horsepowerguru427]

From what i understand the pcm is always going to reference the VVE on gen 4 and 5 even if you have it in MAF only. At least as a sanity check. Im not sure how accurate that is but i know the ones ive tuned drive much better after the VVE is done as well as the MAF

[WantonNegLect]

Thank you HPG and MPJ, I'll look into your suggestions. Definitely leaning towards starting a tune using narrowband.

Posting cam spec here and also what I BELIEVE to be the cam spec for my 2012 "LC9" engine. Trying to find more than one source to confirm stock cam specs. Need to confirm, I'm seeing numbers indicating my new cam is "bigger" and others indicating my new cam is "smaller"... it's a little frustrating finding the specs to say the least.

Stock cam spec:
PN# 12625436
Intk/Exh
196/201
.481/.481
116+2

Attached is my full cam spec sheet, but for simplicity also here:

Cam spec:
intk/exh
200/204
.5015/.5014
114+3

I'm around halfway through Greg Banish's "Advanced Tuning" book. Boy, I wish I would've read this before purchasing my cam. Lot of stuff I hadn't even considered... What will I learn next? haha

I realized, I might also need to change my injection start timing depending on the deviation of the intake opening compared to crank position. But, getting ahead of myself here.


So, if i understand correctly, the intake opening event would occur 2 degrees crank (1 deg cam) angle sooner than with the stock cam? Thus, i need to move my injection open signal event 2 crank degrees sooner as well to ensure proper mixing of air and fuel? What else should I consider with a smaller LSA and 1 degree extra cam advance?

Anyway. I will look further into what you guys have said thus far, and keep reading the book.

[horsepowerguru427]

Thats a very small cam honestly, Ive got a 209/217 .550/.550 112+1 in my yukon and there wasnt enough (any actually) overlap to justify injection timing. It had no positive effects when changed. You should be able to start, idle, run, and drive just fine with that cam. So Just tune VVE and MAF and youll be ok.

[WantonNegLect]

Hello, back again. Got the truck running. First time the truck engine turned over on it's own power since dismantling for the DoD delete in almost 3 years i think... wow... To be fair, I had to do a LOT more to the truck than just that. Let's just say, the only original body part on that truck is the front fenders and hood. Plus, I was building a shop on my own... Excuses excuses...

Will post the log file here. Need a little bit of help. This was just moving the truck around my yard and backing it up a slight hill to get it into my shop. It was tight so I had to adjust my vector a few times to miss the other truck I have parked in there haha

Anyway, Issues...

1. My Ballenger output in the left hand side is reading out in AFR. I thought I had it set up for Lambda. What did I do wrong? The correct lambda equation option is AFR 500 (NOT AFR 500 V2)
2. My WB error graph is also not working... Again, not sure what I did wrong
3. Noticed my AFR values had pretty big swings early in the log file before it stabilized in the mid 13s. Not fully warmed up I know, but that was a little concerning to see it swing from 14 to 9 to 13.5 within the span of a few seconds.

Thanks for any help you can offer. The thread on simultaneous tuning of the MAF and VVE was certainly interesting. Hence, logging MAF, Dynamic airflow, and VVE estimation.

[WantonNegLect]

it hit me, wasn't logging MAP so that's probably the reason why it wasn't populating the WB error table. Will drive the truck again soon and see if I can fix it