Is there something wrong with my 85mm mass air
12-08-2006, 08:17 AM
#1
Is there something wrong with my 85mm mass air I have EFI Live and run some wot runs and my 85mm mass air ( for example) at 6500 rpm its showing 50.88 lbs.min. and in the EFI tuning its showing at 6500 rpms its set at 42.36 lbs.min. and all of setting are out real bad like that from around 2000 rpms and up, the higher it goes the weirs it gets , But the car seams to run o.k., I have a LS2 418cid. with Holley 90mm TB , Fast 90mm intake and Dart Pro1 cnc by (Texas Speed ) with 2.100" int, & 1.60"ext. 255cc runners , 42.lbs injectors .Do i need to recalibrate the mass air if so how do i do it with my EFI Live V7.3 . and on the the graft the air flow is real spiky across the board at wot but smooth at cruse. Its hard to explain , i wish i could take a snap shot of the EFI Live graft to show but don't know how to do that nether.
12-08-2006, 08:19 AM
#2
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MAF tables have MAF Frequencies....not RPMs. 
The number in the cell is obviously grams/second (or in your case lbs/minute) and the number next to the cell is MAF Hz. You need to log the raw MAF Frequency to see what cell is being referenced.
As for the smooth vs. spikey graph, that's normal. The intake can be quite turbulant as airflow increases. I think it in part has to do with the valves opening and closing as the cam turns. Imagine being in a wind tunnel and there are 8 doors at the end for the air to flow through, but only two doors are open at a time. They're opening and closing really fast. I would assume airflow is going to speed up and slow down more and more as it increases overall while the rpms increase....not really remain consistent.
The number in the cell is obviously grams/second (or in your case lbs/minute) and the number next to the cell is MAF Hz. You need to log the raw MAF Frequency to see what cell is being referenced.As for the smooth vs. spikey graph, that's normal. The intake can be quite turbulant as airflow increases. I think it in part has to do with the valves opening and closing as the cam turns. Imagine being in a wind tunnel and there are 8 doors at the end for the air to flow through, but only two doors are open at a time. They're opening and closing really fast. I would assume airflow is going to speed up and slow down more and more as it increases overall while the rpms increase....not really remain consistent.
Last edited by SSpdDmon; 12-08-2006 at 08:25 AM.
12-08-2006, 08:27 AM
#4
That what i did, i under stand that its not rpms ,im just saying at that point , I don't have the graft with me since im at work, but at that frequency ,the mass are is set at 42.36lbs.min and at wot at that frequency or (Hz) it shows 50.88lbs.min. Im just asking should they match or be close.