HP Tuners Tutorials

[MDPotter]

Gregski, if at any point I'm cluttering your thread let me know.

I was successful in connecting to my 68 and recorded a log and also downloaded the tune. From my very limited knowledge of tuning, it appears to be running pretty well. I created a configuration from gregski's posts.

Some observations from the logging:
-I noticed that the MAF, MAP, and Speedo gauges weren't showing anything. I found out that if I added those channels that the gauges would provide a reading. I got the MAF and Speedo to work, but still haven't found the right channel for the MAP.
-At idle, STFT's were between 0 and -3.
-At cruise, STFT's were between 0 and -10.
-Barometric pressure reading was about 5 inHG lower than the weather app on my phone shows. But the same thing on my 2016 and my fiancee's Dodge Nitro. Why is that?
-There was a few minutes during the drive that STFT's were at 0, is that normal?

Looking at the tune:
-Is shown as the correct donor vehicle, just a different VIN
-Power enrichment appears to be enabled
-Segment swap for 4L80E
-Speed limiter disabled
-A lot of DTC's are disabled, much more than gregski indicated in earlier posts. Such as fuel trims, PCM speed output, MAP sensor, IAT sensor, O2 sensors (bank 1 & 2, sensor 1), MIL control circuit, TPS, all "U" codes. I am thinking about enabling everything except the DTC's that gregski noted. Thoughts?

Idle Snapshot:


Cruise Snapshot (O STFT's):


Cruise Snapshot (moving STFT's):


Primary VE Table:


Again, I am in the very early learning stages of tuning, but it looks like I should give the tuner some credit?

[Gregski]

Originally Posted by MDPotter

Gregski, if at any point I'm cluttering your thread let me know.

Yeah, stop cluttering "my" thread! Are you kidding me, this is great, I actually appreciate you doing this as it helps us test the tutorial if you will. I'm going to address some of your questions in separate replies.

[Gregski]

Originally Posted by MDPotter

Some observations from the logging:
-I noticed that the MAF, MAP, and Speedo gauges weren't showing anything. I found out that if I added those channels that the gauges would provide a reading. I got the MAF and Speedo to work, but still haven't found the right channel for the MAP.

Sorry it took me a while to get back to you mate, please try the:

Intake Manifold Absolute Pressure (SAE) channel

[Gregski]

Originally Posted by MDPotter

-Barometric pressure reading was about 5 inHG lower than the weather app on my phone shows. But the same thing on my 2016 and my fiancee's Dodge Nitro. Why is that?

LOL, Location: Western Colorado ie Elevation, but mad props to you for doing the stare and compare with another vehicle, well done mate!

[MDPotter]

Originally Posted by Gregski

LOL, Location: Western Colorado ie Elevation, but mad props to you for doing the stare and compare with another vehicle, well done mate!

That makes sense and that's what I expected. Apparently the reading from The Weather Channel isn't accurate. Not a big deal, just something I noticed. Just another reason not to believe the weather man.

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Well, it's been a while, might as well get back into it. I honestly don't recall where we left off so forgive any overlap as we dust off the cobwebs together.

Let's free up some oomph in our trucks. For those of you who have have tuned with a screw driver before ie tinkered with a carburetor (pronounced: "a controlled fuel leak") you are probably familiar with an accelerator pump and those of you who know what a Double Pumper is get double bragging rights! ha ha

basically when you are just cruising along and you step on the gas pedal, it takes a while for the system to react, since air travels faster than fluid, the gasoline needs a little extra kick in the pants so that we don't lean out and have to fix things with our wallet.

So in the carb world this rubber diaphragm spring plunger thingie would literally spray extra fuel into the throat of the carb like a Windex squirt bottle.

Now in the HP Tuner world with EFI the similar system is called Power Enrichment and it just so happens that it is crippled on most if not all truck/SUV Third Gen LSes.

Coming up next we will take a closer look how our engines / PCMs come configured from the General, and how we can "fix" that and get that feel by the seat of our pants acceleration.

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

We find the Power Enrichment settings in two places in the VCM Editor. The first place is under Engine \ Fuel \ Power Enrich tab and then the Delay section

Here we see how a Tahoe engine was configured:

RPM 5,000
Delay 0.8

This basically means do not kick in Power Enrichment unless this Soccer Mom holds the RPM at or above 5,000 for more than .8 seconds, (basically that will never happen) so essentially PE is disabled on this SUV

Note: your default factory settings may vary slightly, the RPM may be 5,500 and the Delay may actually already be 0

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

we need to zero out both fields so they look like this:

this eliminates any delay and PE will kick in provided some of the other conditions are met but at least the RPMs won't prevent PE from kicking in

we will address the other influencers next

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Throttle position is the second thing that effects or prevents PE from kicking in

We find these settings on the same page under Engine \ Fuel \ Power Enrich tab and then the Throttle section under both the Hot and Cold buttons

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

here is what the default Hot and Cold tables look like, they basically say when the throttle is at 90% at the above listed RPMs only then kick in Power Enrichment, so again pretty much never when for example you try to pass somebody on the freeway, unless you mash the gas pedal

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Alright, how do we fix this? Well there's three ways to go about it if not more, and it's a bit more of an art than science, in other words do it to your liking and see how your truck responds.

So here is one way to do it, start by cutting that number approximately in half, (for both the Hot and Cold tables) so instead of having the PE come in at 90% throttle set it so say 50% like so.

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Another way to approach this would be to say well I don't want all that extra fuel at the lower RPMs so maybe don't kick in PE until 2,000 RPM or what ever RPM you feel is right for you, like so:

And once again make sure you update both tables, the Cold one especially as the PCM hardly if ever will get to the temp to use the Hot one

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

some of you may have heard the old adage "good composers borrow, great composers steal" which brings us to the third way of adjusting those Hot and Cold PE tables

we can look how GM did it from the factory in the true LS1 sport cars such as the 2001 Camaro, now keep in mind that engine is a 5.7L and has some different components on it, but here's how them cars are set up as a reference, note how their Hot and Cold tables are actually different!

Top Tip: You can look at all the stock tune files from the HPTuners.com website. First you need to download their Software for FREE, it is completely allowed and legal and then you can download stock tune files that people have uploaded from their vehicles to their website for others to use.

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

well so far we've told our engine computers to turn on Power Enrichment and when to do it, but what is it actually going to do?

so to wrap up Power Enrichment we must discuss the Power Enrichment EQ Ratio table, what the hewk is it?

first EQ stands for Equivalence Ratio, and we find it on the same page under Engine \ Fuel \ Power Enrich tab and then the Power Enrichment section under the EQ Ratio (Gas) button

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

this table tells the computer what the air fuel ratio mixture needs to be or needs to equal at a certain RPM

so the computer doesn't just go hey the guy pressed the gas pedal more than 50% and the RPMs are at 4000 so shoot some more gasoline in the engine, instead it says at 4000 RPM we need to shoot precisely this set amount of fuel to make the gasoline mixture equal stoich (14.681) divided by 1.246

so that equals an AFR of 11.78 in essence richening the air fuel ratio

(remember about 13.50 is neutral or cruising AFR, as an example anything lower to like 11.50 is rich which means more power, anything above that is lean up to for example 15.50 which is fine for say coasting on the highway)

I'm an old timer so I speak in AFR and not in Lambda like all the cool kids do now

so we can play with the numbers in this table a little bit, since simply going richer does not mean more power, there is a sweet spot, what I like to do is see if coming in richer sooner has a positive effect in other words do you get more power at lower RPMs, then I do the opposite and see if I can lean out the fuel a little at the higher RPMs if there is no more power gains up high, or you can shift that Ratio to the left a few cells or shift it to the right a few cells type of thing

[ls1nova71]

Hey Gregski, I'm really glad you are back to continuing this thread, it's very helpful. I've read it several times, just wish I could remember it all! It seems if I don't use this information for a while, which isn't all that long to be honest, I just loose everything I had read and learned. Not sure if that says more about HPTuners or me! LOL But keep it up, its a great source of info for the beginner.

[Gregski]

Originally Posted by ls1nova71

Hey Gregski, I'm really glad you are back to continuing this thread, it's very helpful. I've read it several times, just wish I could remember it all! It seems if I don't use this information for a while, which isn't all that long to be honest, I just loose everything I had read and learned. Not sure if that says more about HPTuners or me! LOL But keep it up, its a great source of info for the beginner.

thnak you so much, honestly, ditto, lol and I am glad you are not tinkering with it daily, that's the whole point, you tune it then you drive it, there are just so many nooks and cranies but that's no different than forgetting what size jets you put on your Holley last time you re jetted it back in the day, even if you swore you'll remember 72 since that's the year you were born, ha ha, just sayin'

[MDPotter]

Glad to see you back adding to this thread!

[Gregski]

Originally Posted by MDPotter

Glad to see you back adding to this thread!

Thanks mate, it was bugging me that I left it unfinished!

[Gregski]

HP Tuners Top Tip # 47

If you were away from HP Tuners for a while like I was (looking at you COVID-19) and now you may be thinking of doing some more tinkering, you may find this tip useful.

Say the last time you tuned was six months ago or a year ago, and now you want to change something else. Well if you are like me then you may wonder where did you save that last file to? Is it on your office PC that you upgraded since, or on your laptop that you loaned to your daughter for school?

In that case the best thing to do is read the configuration from your PCM like we did in the very first tutorial, so simply refer to that and follow those steps, and I recommend you call it something like 000 - Baseline 03-21-2021 that way you will be certain you will pick up from where you left off, since sometimes your latest file may be something like 15 - Tried Something That Didn't Work and then you forget that you went back to 14 - Last Known Good Config

yes that has three leading 000 in it to signal a new series of tuning a new chapter if you will, but you do you

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Let's take a look at some Channels that can help us gauge first if Power Enrichment is even coming on, and then how much it is effecting our Air Fuel Ratio and when.

To do this we need a minimum of three channels, so we'll start with those and then add some more for better context.

Throttle Position channel (so this is the throttle blade position on the nose of your engine, and not the actual throttle pedal, since some of us may still have drive by cable, meaning non electronic throttle pedal)

Equivalence Ratio Commanded channel (this is the adjustment that is being made to our Air Fuel Ratio, so since we are dealing with Power Enrichment it will always be the amount we are enriching) we can choose what units to show this in, either Lambda or AFR. If we choose lambda it will show the value of 1.0 until PE kicks in then it will drop below 1.0 to something like .85 to show a richer fuel mixture. In other words when we are just cruising the system says lets take our perfect AFR of 14.68 and multiply it by 1.0 and that doesn't change anything cause one times four apples is still four apples type of thing. Again the cool kids tune in Lambda but I can barely wrap my head around AFR. It doesn't matter which units you use as long as you're comparing apples to apples.

Air-Fuel Ratio Commanded channel (this is the actual final result after all the adjustments, this shows what Air Fuel Ratio we are running at this particular moment in time, if Power Enrichment never comes in then we strive for a perfect Stoich ratio of 14.68, which is a theoretical number that says 1 shot glass of pure(ish) gasoline requires approximately 14 and a half shot glasses of air to burn at it's best)

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

Now to get a better perspective and to remember what it is that was happening when you go to review the log an hour later or a week later, I like to add a few more helper channels if you will

Engine RPM will tell us when we shifted gears

Vehicle Speed obviously tells us that we've tickled the skinny pedal

feel free to add what ever channels will help you out analyze things, just keep in mind the more channels you add the slower the data transfer may be as you log

[Gregski]

Part IX - Enable Power Enrichment aka Accelerator Pump / Secondaries

So we could stare at the values in these channels in the left pane of our HP Tuners Scanner but things really paint a better picture when we add a Chart vs Time to our layout in the right hand pane.

So essentially the Channels are just a way of capturing the data we need and not having to bring in all the other noise, but we really analyze things on the right hand side of the Scanner screen.

Let's take a look at a couple Chart examples, this first one simply illustrates starting from the top, that we just shifted from 1st to 2nd (top RPM red line) the middle orange line shows us building up some speed, and the bottom green line shows how we were at Stoich AFR and then dipped into Power Enrichment and richened the air fuel mixture to 12.26 proving to us that Power Enrichment indeed kicked in.

You can start by adding these channels and creating these types of simple charts prior to making any Power Enrichment changes to your tune, and you will see that that bottom green line never dips for you, well unless you go nuts and hold your gas pedal down to the floor for a second above 5,000 RPM, not recommended, and not safe out on the road

[JamieGallien]

Gregski, Thank you so much for this! I have a 65 C10 SWB with a 5.3/A4 that I am almost ready to test the fuel system and fire up for the first time. I had my pcm wiped/prepped by a mail order guy. I took the time to copy/past and make a PDF with all of your steps so I can read offline. Rest assured I will be going through your steps to make sure everything in my PCM is right.

[Gregski]

Originally Posted by JamieGallien

Gregski, Thank you so much for this! I have a 65 C10 SWB with a 5.3/A4 that I am almost ready to test the fuel system and fire up for the first time. I had my pcm wiped/prepped by a mail order guy. I took the time to copy/past and make a PDF with all of your steps so I can read offline. Rest assured I will be going through your steps to make sure everything in my PCM is right.

Awesome, use the compare feature I mentioned somewhere early on or reach out to me and we can text or IM if you have any questions, a lot of those tuner guys/gals are really good the problem is they don't have the access to your actual vehicle they can not go for a ride along with you with their laptop in their lap and log any data, that's where the magic happens