MAF Tuning help

[bkelsheimer89]

Hello all,

I need some guidance on what I am doing wrong. I bought this car with modified heads, long tubes and duals, bbk intake, and an SLP lid. It had been previously tuned by an unknown shop and runs alright. I have added an 85mm TB, Z06 MAF, And bigger intake tubing. The current tune still runs ok, but I wanted to try my hand at a MAF tune and I am unsure of where I am going wrong.

I don't have a good factory tune to start from so would anyone be willing to check out my MAF tuning file. With the MAF tuning file loaded in it runs extremely rich non stop. I got the car warmed up before I loaded in the tune as well. Any help would be appreciated.

[5FDP]

The open loop EQ ratio is not set to 1.00 for cells at operating temp, so if you are trying to tune it with it commanding numbers of 1.05-1.08 all the time, the MAF tuning will all be wrong.

[murfie]

https://forum.hptuners.com/showthrea...2-Z06-Corvette

First step I would copy in the MAF transfer values [ECM]12160 from a stock Z06 file to start with. stock files in link above. Then try adjusting as needed from that.

navigator.jpg


If you don't want to do that, multiply your entire MAF transfer by .65, and take another log. (this basically gets you close to the stock Z06 transfer values.)
Using a predifined math AFR error to get a percentage error into a graph against the frequency values from the tranfser to adjust it with.
scanner should come out looking some what like what you see pictured.

MAF tuning.jpg

You can then just copy the values from the graph and paste special- multiply by % half them into your tune file. Watch for any erroneous changes that throw the nice smooth curve off too much.

[bkelsheimer89]

The open loop EQ ratio is not set to 1.00 for cells at operating temp, so if you are trying to tune it with it commanding numbers of 1.05-1.08 all the time, the MAF tuning will all be wrong.

When I get home I will change them to 1.0. I believe my operating temp is set to 130. Should I only change the cells in that range or should I change the range through the whole temp range?

[bkelsheimer89]

Using a predifined math AFR error to get a percentage error into a graph against the frequency values from the tranfser to adjust it with.
scanner should come out looking some what like what you see pictured.

Is this the "paste special % .5" you were talking about? This is how I planned to change the MAF curve going in.

[murfie]

Is this the "paste special % .5" you were talking about? This is how I planned to change the MAF curve going in.

Yes. It's mainly deceleration you have to watch out for. Filtering it out of the logs is best.