LS7 card maf

[VX L67 Getrag]

Thats pretty good to know as far as we all knew they didn't have this restriction with the LS7 although we did about the LS6, & seems there's more weak LS6 maf's than what there are strong, would be good to know how to tell those apart guaranteed!

Another issue I see with this being published know the cheaper chinese copies will all start coming out with the real digits on the LS7's too!

[yoda69]

OK VXL67, not as simple as just doing a global % change as it looks like there are a few other things coming in to play based on the file you put up of the different curves.
What appears to be happening is:
Low Hz - smaller tube has higher flow for the same Hz reading, not quite sure what's happening here, every reason I can think of would cause the opposite.
High Hz - smaller tube has lower flow for the same Hz reading, as expected due to smaller diameter flowing the air faster over the sensor, even though the volume will be lower

When looking at the percentage difference, there is some interesting "bumps" around the 3000Hz area in both, these may just be a property of the MAF or an area where the airflow changes from laminar to turbulent flow or possibly just a difference in the cylinder pulses from an L4 to a V8.

Looks like there is no easy way to convert between them and the size, shape and material of the pipe and location of the MAF sensor (on straight or near radius) makes a lot of difference.

Different LS7 Maf freq's - Copy.xlsx

(26.25 KiB) Downloaded 328 times

[VX L67 Getrag]

Thanks for looking at it, if it's that different a curve it's a bit of a worry for those that are using it on the factory standard calibrated maf setting & only adjusting the injector rate.

I'm not at a computer so can't look at it till tomorrow but thanks again for your time!

[antus]

Yes, it still needs tuneing

[VX L67 Getrag]

Seeing that LS7 with the 6.0L corvette is going to be the closest so long as it's put in a 100mm tube, how do you go about extending it from an 8 table size format to a 14 table size format with keeping the curve the same?

I know your not supposed to edit the black section but thats the only way I could think to get the curve to show compared to original, here's what I did not sure if it's right?

[antus]

I'd say add the original pcm table data to the cross referencing spreadsheet and use that to calculate the % difference so you can use yodas spreadsheet.

[VX L67 Getrag]

Just checking does it look like I'm doing this right....

MAF Tables 14 Tuning(try Calculating LS7 for grams per second).xlsm

(60.98 KiB) Downloaded 275 times

I've only done the first 2 tables so far & is very time consuming & not 100% whether I'm aiming for the requested or actual grams per second to be the same as factory?

[antus]

Yeah, your going the wrong way. % change is positive (flowing more air at the same hz). Then you need to add a row to the MAF Table Data Correction Factor table, in to cell X39 (value like 5 or 6). Then keep doing what your doing and gradually increase correction factor for any row that has errors until the errors are gone and the last row of the maf data is between F0 and FF (for best resolution). Use decimal places for precision.

[VX L67 Getrag]

If you have a look at the requested & actual commanded grams per second in the column there exactly what is set as stock in the HP tuner file?

[antus]

I dont trust hptuners, use efilive if you think its not looking right. The demo version and .tun from tunefiledepot is enough for this. I dont have enough time to check your work further.