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Author Topic: Newbie Question - MAF Tuning  (Read 973 times)

Offline gzus13

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Newbie Question - MAF Tuning
« on: December 12, 2017, 08:55:40 PM »
Thanks for looking.  I'm waiting on a response from my dealer about this also, and in the meantime I was hoping to get some opinions.

I'm having some trouble populating the VE map for my ITB / turbo engine with speed/density loading.  I don't have easy access to a dyno, so I'm considering switching to MAF based loading.  I'd like to use a blow-through setup to put the sensor as close to the throttle bodies as possible.  The ECU is a 128 v5.30.

A few specific questions:
1. When using MAF sensors, is the VE map used at all?
2. Is it reasonable to try logging MAF output to back-calculate VE?
3. In the fault manager, there is "Enable_MAP_Speed_Density" as an action - I assume this will switch to speed density loading if the MAF sensor throws a fault?
4. Can anyone recommend a good MAF sensor to use (and provide a calibration curve)?  The intercooler pipe/plenum inlet is 3in diameter and max output should be around 500hp.  I've heard that the GM cartridge sensors can work well blow-through, but I don't have a sensor P/N or cal curve.

Thanks a lot for your help,

Offline FluxCapacitor

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Re: Newbie Question - MAF Tuning
« Reply #1 on: June 11, 2018, 08:35:12 PM »
I realize this is a zombie bump..... but I wouldn't want to run a MAF in blowthrough.

Please correct me if I'm wrong, but the MAF is always setup in draw through in OEM applications, turbo or n/a.  The problem with blowthrough is that the MAF's I.D. is calibrated to the sensor which means the opening the air is blowing through and being metered in is a constant in an equation to calculate air volume.  Another constant in this equation is that the air coming in is atmospheric pressure air.

When you throw boost into a MAF (blow through) or put the MAF sensor in a housing/weld-in boss that is not the same size as factory then you will have to compensate for the difference some how.  Yes, this can be done but you've introduced yet another variable that you must tune in your system to get it running properly.  It's easier to avoid all together by using MAF in draw through and metering boost with an aux MAP sensor.

Source: I have watched a lot of DSM guys have tuning issues with a certain piece of hardware that was popular to make a GM MAF run in blowthrough.