Need advice on tune and MAF tables

[Nickatina7]

My first question is about the MAF table. I have a c6 corvette over the radiator intake with a card type MAF that i pretty much have installed now. I am just looking every where for the MAF tables I can enter in and start with for the LS3/7 card type MAF that I am installing with it. If anyone has the tables to start with that would be awesome.

Also if anyone can just look over my tune and give me some critisism that would be awesome.
I logged some drives and noticed that when I did some WOT pulls the MAF would drop out and spike up very bad. It would also have a direct influence on the injector duty cycle. The duty cycle would spike with it over 100% sometimes even to 115%. wondering why this would happen. I will attach the data logs and my current tune.
Since I'm going with the bigger cam I was told I could use these stock injectors. Any input if i should upgrade or stick with the stock injectors is appreciated. Cam spec I'm installing is 227/234 .614"/.576" 113+2

The engine how it sits now is all stock besides long tube headers with no cats going to dual racing beat mufflers and dual exhaust cutouts. Also has a custom 90* intake with the stock LS1 MAF. But I will have the c6 intake set up this weekend.

thanks guys!

[Jalon Sparks]

The VE Table looks rough man. PE Ratio isn't right. you set the PE Ratio table the same number all the way across.

[Oleblu]

It is common practice to set the pe table to command one ratio through the entire table. Some people do some people don't it's no big deal either way.

[dermotw]

I doubt getting a base table will help, because any change to the air path changes the MAF flow/figures anyway... so they are all a bit different, once you start changing bits! But anyway it's quite easy to get a curve if you have a W/B.. Easier than the VE imho. BTW, if you are using a card MAF, are you using the temperature sensor in it as well? If you are, you'll need the list of numbers below for the IAT curve!

BTW also, your VE does not look too bad to me, I don't even bother smoothing the very small blips myself. Stock injectors I'm not so sure about, hopefully someone with more knowledge can say...

kr D.

?C 0 6.25 12.5 18.75 25 31.25 37.5 43.75 50 56.25 62.5 68.75 75 81.25 87.5 93.75 100 %
Inlet Air Temp 140 107.2265625 75 58.90625 49.453125 41.6796875 33.90625 25.546875 18.1640625 11.71875 6.2109375 1.328125 -4.7265625 -13.203125 -24.4921875 -36.6796875 -40

[Jalon Sparks]

If Duty Cycle exceeds 100% most of the time you need bigger injectors.

[Jalon Sparks]

I doubt getting a base table will help, because any change to the air path changes the MAF flow/figures anyway... so they are all a bit different, once you start changing bits! But anyway it's quite easy to get a curve if you have a W/B.. Easier than the VE imho. BTW, if you are using a card MAF, are you using the temperature sensor in it as well? If you are, you'll need the list of numbers below for the IAT curve!

BTW also, your VE does not look too bad to me, I don't even bother smoothing the very small blips myself. Stock injectors I'm not so sure about, hopefully someone with more knowledge can say...

kr D.

?C 0 6.25 12.5 18.75 25 31.25 37.5 43.75 50 56.25 62.5 68.75 75 81.25 87.5 93.75 100 %
Inlet Air Temp 140 107.2265625 75 58.90625 49.453125 41.6796875 33.90625 25.546875 18.1640625 11.71875 6.2109375 1.328125 -4.7265625 -13.203125 -24.4921875 -36.6796875 -40

You don't smooth your VE Table(s)?

[gvilla]

New to tuning, this here may not be the most correct way of doing things, but I`m a bit lost. I was wondering if you guys could help me out. Ive been trying to figure out how the ecu calculates the airflow, g/cyl, when there is no MAF sensor in vehicle.

[Nickatina7]

Hey guys been doing a little bit of research. I found this step by step guide on doing SD tuning which I will start on when this monsoon stops here in northern cali.


Only thing i think i need is the values for this card type MAF and possibly the IAT values. I am done installing the c6 intake and the card type MAF now. I was going to SD tune then possibly bring the MAF back into play. But i will for sure have to keep it plugged in for the IAT.

Just really hoping someone can point me in the direction of what values I can enter for this card type LS3 MAF and IAT. I want to at least get it started and running with this intake on then i will log and SD tune from there.

[Nickatina7]

It wouldnt let me paste the tuning guide i found I'll try and post it on a different link.

[Nickatina7]

If Duty Cycle exceeds 100% most of the time you need bigger injectors.

I did many logs in the past with this tune on the car and the injector duty cycle never went above 78% at WOT. It was only the last few logs where the MAF jumped all over and the duty cycle % went above 110%. Hoping to clear it up with speed density tuning and see how high the duty cycle actually goes. Also at WOT my AFR was at 10.5:1 which is way too rich.

[5FDP]

For sure add knock retard, injector bank 2 pulse width and commanded AFR to your main channels list for logging.

Not sure what guide you have found but for MAF fail settings, they are MAF fail high set to 0hz, all 3 MAF dtc's set to fail on first error. Remove any MAF sensor related channels when tuning VE only, to prevent it from skewing data.

[Jalon Sparks]

Most vehicles I usually just tune open loop speed density. just easier for me. I set the MAF Fail to 0 and put dtc's on first error. then set up my PE settings. make sure you don't log any maf related channels like 5FDP previously stated.

[Nickatina7]

For sure add knock retard, injector bank 2 pulse width and commanded AFR to your main channels list for logging.

Not sure what guide you have found but for MAF fail settings, they are MAF fail high set to 0hz, all 3 MAF dtc's set to fail on first error. Remove any MAF sensor related channels when tuning VE only, to prevent it from skewing data.

I have since made a few changes to what im logging but it seems that its not logging knock retard even though i have added the channel. Or at least it never shows any value for it.

I was hoping someone would have a scanner lay out they can send to me that is set up a little better? Or a place where i can get them?

here is my last log. Just an easy drive to work.

[5FDP]

It works, you just didn't look close enough.

Midway through the log at about 7:49 in you are doing about 100mph and it's showing around 3 degrees of knock at part throttle.

[Nickatina7]

It works, you just didn't look close enough.

Midway through the log at about 7:49 in you are doing about 100mph and it's showing around 3 degrees of knock at part throttle.

Ok thank you i see it. So.... dumb question but shouldnt i never see knock? That means the sensor detected knock correct? is that little bit a bad thing?

[5FDP]

The saying goes that any knock is bad knock but that's not really true. If you ever look at many stock calibrations and logs files they all have spark knock/predicted knock built straight into the tunes. Heck my when my truck was stock and it would have upwards of 3-6 degrees of knock just at part throttle or when you transition the throttle from a low TPS to a high TPS quickly.


So technically speaking, anything that is a a low load/low rpm or even a part throttle situation outside of PE it is okay to have spark knock. It's not going to damage anything with low knock numbers. If you were seeing tons of knock retard under heavy throttle/high load you would want to be concerned about that.

[Nickatina7]

I was looking at using this tune on the repository and wondering if it was any good. I cant remember if the LS6 MAF is card type. I thought it was only LS3 and LS7. Was wondering if it was a good starting point but the MAF tables look close to my values.

[5FDP]

It's still going to be the LS1 style MAF on that LS1 powered GTO.

It's kind of hard to give you something exact to work off of because you are swapping it into a car that never had one before. If the C6's already use the card style maf just work with something off that to get you going. You'll know right away if it's way too lean or way too rich with a wideband, then make a adjustment off that. Regardless it's going to take you several hours to dial in both the VE and MAF curve on this setup.

[Nickatina7]

It's still going to be the LS1 style MAF on that LS1 powered GTO.

It's kind of hard to give you something exact to work off of because you are swapping it into a car that never had one before. If the C6's already use the card style maf just work with something off that to get you going. You'll know right away if it's way too lean or way too rich with a wideband, then make a adjustment off that. Regardless it's going to take you several hours to dial in both the VE and MAF curve on this setup.

I found a 2008 vette stock tune and just cant figure out how to copy paste the MAF table to my tune. I can use this to get it running then tune the VE and MAF from there. For some reason it wont let me copy and paste it though. Here is the stock 2008 vette tune. Which should be where my intake came from.

[Nickatina7]

The MAF g/s on the 08 Vette go up to 1,500 but on my LS1 MAF it only goes to 511 g/s. I tried copy and pasting the frequency values onto my tune but it maxes out at 511 g/s around 8.250 Hz. How do I fix this? I'm trying to get this card type MAF to work with the engine now so I can get it running, then I will SD tune it after that.

heres the stock 08 vette tune that I have.