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Thread: Why is my maf voltage go up but my maf value go down?

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Posts: 1-6 of 6
2015-12-13 03:34:43
#1
Why is my maf voltage go up but my maf value go down?
I am looking at my log. I notice my af ratio getting leaner as the boost.

After 4v it goes to the left and down insted of going right.
Why might it cause that.
I turn on my knock analysis and it surprise me when it didn't give me knock retard. Nothing change , out of the blue no knock retard.
Previously I have knock retard at 1 psi. I swear this motor is bipolar or possessed .
Here is my tcd and tcl.
Can anybody give any advice or comment on my tune.
Any help is greatly appreciated.
Thank you.
2015-12-13 15:04:46
#2
Because the RPM is increasing. MAF load is calculated by dividing MAF VQ by RPM, so as RPM goes up, and MAF VQ stays fairly constant, MAF load will decrease.
2015-12-13 18:42:16
#3
The maf voltage did not stay constant. It is increasing
2015-12-13 20:30:04
#4
Yes, but the RPM is increasing at a much more rapid rate.
2015-12-13 21:19:08
#5
Ok. I see it now. The fuel need to be increased to 11.5afr. How about the timing ? Is 18 degree at 20psi safe enough. There is no knock. Knock voltage is around 2.5 v


One more question. Is 20 psi the max you can run on pump gas?. I heard this from many forum. That is why I only run 20psi on garret 2871r. Or do you run as high as you can until you encounter knock. I mean increasing 1psi at a time
Last edited by zurud on 2015-12-13 at 21-28-29.
2015-12-13 21:46:41
#6
I will defer those questions to the much more experienced tuners on the forum.
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