1998 C1500 truck 5.7L Vortec tuning

[AlanDC]

Guys, I need some advice on tuning my truck. Please keep in mind my location (Medellin-Colombia) and the limited access that I have for some performance parts specially with COVID19 thing out. I know the 0411 PCM and wideband is by far the way to go and I'll do it later, but I want to play with what I have now on hand.

1998 C1500 truck (4x2) 5.7L Vortec - K&N complete CAI - MSD 6A ignition/MSD spark plug cables - Long headers - magnaflow 200 cells cats - Flowmaster super50 2in/2out - 4L60E recently rebuilt - Stock tq converter - Deleted EGR/EVAP - upgraded spider injector MPFI - I believe someone put before a high flow MAF or modified the stock one (doesn't have the hive cells).

I recently took apart 90% of the engine (with the crankshaft and block on the truck) and this was added: Compcams 08-501-8 cam Adv Int/exh Dur: 264/269 LSA:112 Int/exh Duration at .050: 212/218 Int/Exh Lift: 0.488/0.495 - Valve springs, seals and spring retainers to accomodate the new cam lift on the stock heads - Ported stock heads and resurfaced valve seats. New piston rings, rod bearings, gaskets, seals, timing gears and chain, etc.

While we're in quarantine in my City we're just allowed to go out 2 days/week with a lot of restrictions, I'm not able to do much testing on the truck. I've felt a low end power/tq loss (I believe because of the new config) and because of the region is very altitude variant (lot of mountains, etc) I want to try to re-gain with software what I have lost with the new hardware. I've included the stock tune, modified (last version) and 2 logs of my short runs. My comments:

- I've seen another VE tables in this Gen3 thread and everyone has regular values in percentage 40-50-70-90% If you see my table is in different range. I added +10% of the values in the main region to see how it goes, but no noticeable changes on the engine behavior.
- In engine airflow tab, I've read a lot and seen videos about failing MAF to fill VE and running MAF only to fill MAF tables but since I'm not able to hook a WB and be out in the street making some runs, is there any general rule or someone have tried doing this in a similar year/engine/trans config that can share the airflow tables (VE and MAF) to give it a try?
- I've not made any changes on engine timing. Any advice here based on my config?
- In one of my short runs last week I felt like the trans was slipping a little in 1st/2nd gear WOT. As you can see in my files I give the trans a little pressure increment. Any advice is welcomed since I want firmer shifts.
- I read that the 1998 PCM black connector pin 9 (dark blue) is labeled as Auxiliary Electric Cooling Fan and engine cooling fan feature available in the tune. Has someone tried using that pin to control engine cooling fans? I already did the electric fan conversion with electric thermostat.

[AlanDC]

Any input/advice will be really appreciated.

[AlanDC]

Also, I want to ask wich Wideband will you suggest based on my aplication? I?ve read people with the MPVI2 without pro features (like me) wiring the WB to the EGR cables.

[don-f]

Go to Youtube and search "mpvi2 serial wideband" a lot of good info there.

[AlanDC]

Go to Youtube and search "mpvi2 serial wideband" a lot of good info there.

Thanks for the input. I decided to buy the AEM 30-0300. It?s kind of strange but someone have it in my country but in another city so I?ll be welding the exhaust bung next week.

[don-f]

That is a good choice. https://youtu.be/mGcEw29XZBQ You have several videos to help you hook it up.

[AlanDC]

That is a good choice. https://youtu.be/mGcEw29XZBQ You have several videos to help you hook it up.

Thanks. I got the AEM WB 30-0300 yesterday and I'm planning to install the wiring and gauge this weekend. The O2 bung was welded yesterday so all the work will be at home. I hope to have it ready on Sunday (I can go out that day because of COVID19) to give it a run and possibly some VE and MAF initial tuning.

[AlanDC]

Finally I was able to pull the AEM signal through the EGR wiring (see attached my scanner dashboard and log). I made a mistake when wiring the power 12V to the WB because I tried to use the voltage from the EGR valve. Without the WB connected the Red/Black cables from the EGR measured 12.5V with the switch in the ON position, but with load (WB connected) it dropped to around 1V. I had to rewire the WB power cables inside the cabin... Newbie mistake.

I will set up the VE and MAF only (separate PCM files) to do the test on Sunday, the day I?m able to go out because this pandemic days...

[AlanDC]

Hey all! I was looking at goat rope garage video for MAF only tuning but on my early Gen3 (I know there are some limitations on that PCM) in the engine/airflow/dinamic tab there?s no "high rpm disable" slot. What else can I do to run MAF only?

In min 4:10 If you count the rows on that tab I?m missing numbers: 3, 4 and 17 (see image attached). I?m thinking about lowering the WOT zone TPS to 1%. Any suggestion?

https://www.youtube.com/watch?v=xO_b...L&index=3&t=0s

[murfie]

"The bottom line is that if the engine is at a steady load state or operating at high RPM then the airflow is 100% based on the MAF once you get thru all the filters and calculations. And the SD calcs only get used for transients and smoothing lower speed operation."

https://forum.hptuners.com/showthrea...s-(MAF-amp-SD)
This is in the sticky at the top, under tuing info and how to. Its labeled "great LS1 tuning info", but should just be "Great GEN3 tuning info".

You don't have to do anything, except only look at the log where your MAP was steady. Wot is easy to keep steady. 45% is a bit harder, but a steady foot as RPMs climb easily can do it. You will find doing different steady throttle positions will overlap MAF readings this is normal. It will just be more fuel trim data to use to confirm that point in your MAF transfer is accurate.

If you want to make it easier, and more MAF biased than it already is, raise the LO/HI MAP delta and LO/HI TPS delta defining steady state. I hesitate to advise this as any error in the MAF, can result in lean/rich conditions and cause knock. The MAF is also just inherently inaccurate during these MAP and TPS changes, due to the Manifold filling and emptying causing the MAF reading to change, and not the cylinder filling being the direct cause.

[Russell Boulding]

If you want to make it easier, and more MAF biased than it already is, raise the LO/HI MAP delta and LO/HI TPS delta defining steady state. I hesitate to advise this as any error in the MAF, can result in lean/rich conditions and cause knock. The MAF is also just inherently inaccurate during these MAP and TPS changes, due to the Manifold filling and emptying causing the MAF reading to change, and not the cylinder filling being the direct cause.

I'm not extremely familiar with the platform he is dealing with. But if I were looking at it. I think my approach would be to do as you state above as well as pulling out some timing across the entire table to make it safer from burst knock and go log EQ error against my MAF table with a higher cell hit requirement and potentially some filtering to dial in my MAF. Of course while logging I'd try to avoid rapid transients as much as possible. Do you see anything problematic with that approach?

[AlanDC]

"The bottom line is that if the engine is at a steady load state or operating at high RPM then the airflow is 100% based on the MAF once you get thru all the filters and calculations. And the SD calcs only get used for transients and smoothing lower speed operation."

https://forum.hptuners.com/showthrea...s-(MAF-amp-SD)
This is in the sticky at the top, under tuing info and how to. Its labeled "great LS1 tuning info", but should just be "Great GEN3 tuning info".

You don't have to do anything, except only look at the log where your MAP was steady. Wot is easy to keep steady. 45% is a bit harder, but a steady foot as RPMs climb easily can do it. You will find doing different steady throttle positions will overlap MAF readings this is normal. It will just be more fuel trim data to use to confirm that point in your MAF transfer is accurate.

If you want to make it easier, and more MAF biased than it already is, raise the LO/HI MAP delta and LO/HI TPS delta defining steady state. I hesitate to advise this as any error in the MAF, can result in lean/rich conditions and cause knock. The MAF is also just inherently inaccurate during these MAP and TPS changes, due to the Manifold filling and emptying causing the MAF reading to change, and not the cylinder filling being the direct cause.

Thanks for the input. I'll give it a try after dialing the VE table. I started yesterday and I'm in my 5th run. Still a lot to fix but have had improvements in the ride quality. Stock VE was way lean!

[AlanDC]

I'm not able to log the MAF frequency values vs AFR error (see attached) I've tried different paramenters and combinations. Changing from Hz to KHz but nothing populates the MAF table. I have it activated in the tune, no codes or anything. Any clue on what's happening?

Tune is attached too.

I'm getting MAF sensor readings (see 2nd pic attached) in g/s

[murfie]

Its a seperate channel you need to add. Mass airflow sensor, make sure the definition is [frequency].

MASSAIRFLOW SENSOR.PNG

[AlanDC]

Its a seperate channel you need to add. Mass airflow sensor, make sure the definition is [frequency].

MASSAIRFLOW SENSOR.PNG

Thanks for the fast reply. So, If I don't have the MAF freq channel added in the left I can't see it in the custom chart? Actually I added it today (to see if there's hidden info there) and tried to get some data but when I got the log file open the MAF freq channel automaticaly dissapears.

I will try to log the MAF freq with the added channel tomorrow. Thanks!

[murfie]

When you open a log, what you see in the channel list is the only data thats available to use in charts and graphs.
When selecting channels in the charts and graphs, some times a message pops up asking you about generic channels. Most people just say yes to it. From my picture above you see there are three different mass airflow [mass flow rate] channels to choose from.
A generic would populate in charts and graphs if any of these channels were chosen.
If you say no it will use the specific channel you choose and not a generic cover all one. If you selected mass airflow B, and said no to the generic message, it would show you the data from mass airflow B. If in the next log, you switched the channel to mass airflow, it would no longer populate the graph or chart you made.

If the channel is disappearing, Update your software to the newest. Connect to the vehicle and repoll the vehicle for supported parameters from the vehicle menu at the top of the scanner.
If that doesn't fix it open a support ticket.

[3strokeEngine]

Are you using beta version? I can't open the file...

I have 97 k1500 with a vortec 350 zz4 cam swap and i can help you out. First thing you're going to want to do is give that thing some more ignition timing.

You're correct that there is no way to force the blackbox PCMs to MAF only, you have get your speed density dialed in first, then once you're ready to do MAF tuning setup your error histogram with a filter that only logs when in steady state (also no PID for steady state you have to do some custom math with TPS and MAP sensors to log steady state MAF).

Here is a copy of my tune maybe you can copy paste some of the spark tables and base running airflow to your setup and see how it responds.

Also fuel to wall impact factor in the transient fueling tab is kinda like your accelerator pump. Ive increased those tables aswell

Full specs: 1998 Tahoe PCM, 350 vortec zz4 cam bone stock other than that, 4l60e

[AlanDC]

When you open a log, what you see in the channel list is the only data thats available to use in charts and graphs.
When selecting channels in the charts and graphs, some times a message pops up asking you about generic channels. Most people just say yes to it. From my picture above you see there are three different mass airflow [mass flow rate] channels to choose from.
A generic would populate in charts and graphs if any of these channels were chosen.
If you say no it will use the specific channel you choose and not a generic cover all one. If you selected mass airflow B, and said no to the generic message, it would show you the data from mass airflow B. If in the next log, you switched the channel to mass airflow, it would no longer populate the graph or chart you made.

If the channel is disappearing, Update your software to the newest. Connect to the vehicle and repoll the vehicle for supported parameters from the vehicle menu at the top of the scanner.
If that doesn't fix it open a support ticket.

Thanks again! I added the channel and was able to log the MAF freq into my custom chart. I used your method to reach steady state and It worked for me, specially because I'm in a region with a lot of mountains so it's easy to have the MAP steady with any throtle position going up in the hills.

Are you using beta version? I can't open the file...

I have 97 k1500 with a vortec 350 zz4 cam swap and i can help you out. First thing you're going to want to do is give that thing some more ignition timing.

You're correct that there is no way to force the blackbox PCMs to MAF only, you have get your speed density dialed in first, then once you're ready to do MAF tuning setup your error histogram with a filter that only logs when in steady state (also no PID for steady state you have to do some custom math with TPS and MAP sensors to log steady state MAF).

Here is a copy of my tune maybe you can copy paste some of the spark tables and base running airflow to your setup and see how it responds.

Also fuel to wall impact factor in the transient fueling tab is kinda like your accelerator pump. Ive increased those tables aswell

Full specs: 1998 Tahoe PCM, 350 vortec zz4 cam bone stock other than that, 4l60e

I'm using std version 4.4.4 of the suite. I was able to open your file. Actually we have the same engine/trans combination. I added my last tune for you to try again.

I did the tuning backwards, starting with VE, then MAF and now timing. I'm using goat rope garage method adding 2 degrees to the entire table and running a decent log to see if there's knock at any cell to revert a degree or two, but I'm thinking about letting the timing in some zones nearly stock i.e. idle and decceleration. I saw your timing table and it's configured way different than mine. What method did you use to dial the timing? Dyno?

Can you please explain a little deeper on fuel to wall concept? I saw you have fewer values (part of the table) compared to my table. I want to give it a try but knowing what I'm doing hehe. Thanks in advance!

[Hondaeater]

Howdy AlanDC, Is your AEM WB controller gauge reading accurately to the EGR voltage?
Example: I see your Voltage of EGR is 3.25V in your truckMay 1st scan around timeline 12:00:12. If the gauge is correct with voltage it should be reading 15.03 but it's 10.56 in scanner without subtracting it from 5 Volt signal. This may help. Refer to your AEM manual and look in the 0-5volt Chart.
Tools>>Math Parameter >> Maths-User and select a User Math # you can create an AFR in Scanner. New Variable, select EGR (make sure it backed by Channel list) and fill in the expression exactly like the picture especially the brackets. Then Save and close. In Scanner>>Chart layout>> add series >> insert or change> User defined and select it. I think the Voltage is inverse because the way you wired it but doesn't matter. This will get you the data you want into your scan.
Refer to your AEM manual and look in the 0-5volt Chart. You can replace the expression with the Lambda values and create another Math parameter.

may1math tool.JPGmay1scan.JPG

[AlanDC]

Howdy AlanDC, Is your AEM WB controller gauge reading accurately to the EGR voltage?
Example: I see your Voltage of EGR is 3.25V in your truckMay 1st scan around timeline 12:00:12. If the gauge is correct with voltage it should be reading 15.03 but it's 10.56 in scanner without subtracting it from 5 Volt signal. This may help. Refer to your AEM manual and look in the 0-5volt Chart.
Tools>>Math Parameter >> Maths-User and select a User Math # you can create an AFR in Scanner. New Variable, select EGR (make sure it backed by Channel list) and fill in the expression exactly like the picture especially the brackets. Then Save and close. In Scanner>>Chart layout>> add series >> insert or change> User defined and select it. I think the Voltage is inverse because the way you wired it but doesn't matter. This will get you the data you want into your scan.
Refer to your AEM manual and look in the 0-5volt Chart. You can replace the expression with the Lambda values and create another Math parameter.

may1math tool.JPGmay1scan.JPG

Hey Hondaeater, I'm using the formula provided in my WB sheets [2811.10]*2.3750+7.3125 and actually is fairly the same that shows the gauge (part #03.0300). I've added a screenshot to confirm. Why do I have to take that 5 volts out? In that case, having a 10.56 AFR will result in poor performance. Actually when I reach PE my AFR goes to 12.4 and the AEM WB gets around that value.

To double check it, when I'm near stoick on my WB it's confirmed by the regular narrowband sensors of my truck.