What's inside the knock off LS6 MAF's

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What's inside the knock off LS6 MAF's

Postby tav » Wed Oct 23, 2013 7:47 pm

Alright so I got an LS6 MAF for my L67 because I plan to add more boost to it in the next few weeks.
I bought mine from the 'reputable' seller who for some time has been known to sell genuine LS6 MAF's for a very reasonable price.

However I seem to have got unlucky and got sold some cheap knockoff.

The issue with the knock off MAF's is that the MAF frequency drops off rapidly almost immediately after pulling the car on full boost. This causes erratic fueling resulting in the AFR's spiking to 20+ causing the engine to stumble and break down.

The Knock Off MAF's are surprisingly fairly hard to distinguish from the genuine part. There are however a few subtle differences which tell the two apart:
Knock OFF:
+ Only has 2 Hot Wires (Blue in color, and are smaller than the genuine ones)
+ A diode replaces the 3rd Hot Wire...
+ Has a white sticker on the flat side and no barcode at the bottom.

Genuine:
+ Has 3 Hot Wires (Grey in color, slightly fatter)
+ Has original Delphi part number markings engraved on the body of the unit
+ Has no white sticker on the flat side.

Now that I have no real use for this MAF; it was time to pull it apart and see why exactly was inside and why they decided to use a Diode instead of a Hot Wire.

Before I go any further; here is a picture of the blue Hot Wires / Diode I mentioned earlier:

IMAG0947[1].jpg
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Here's the picture of the white sticker too:
IMAG0948[1].jpg
IMAG0948[1].jpg (852.9 KiB) Viewed 4065 times


I pulled the cover to reveal the PCB... there is some form of non-conductive gel which covers the PCB:
IMAG0949[1].jpg
IMAG0949[1].jpg (979.78 KiB) Viewed 4065 times


This gel stuff comes off fairly easily with a little cotton bud and some light rubbing.

Once you get most of the gel off; soak the PCB with some Acetone. After a minute or two, take another cotton bud and rub the PCB down lightly. The gel should now 'peel' off the board exposing the raw board.
Once you have cleaned up the PCB you can dry off the remaining Acetone.

Under closer inspection, the Knock off MAF uses a 16 bit Digital Signal MicroController manufactured by MicroChip. It's a fairly decent chip. Part Number: dsPIC30F2011

Tomorrow I'll remove the track going to the Diode and see what impact this has on MAF Frequency when flowing high amounts of airflow.

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Re: What's inside the knock off LS6 MAF's

Postby charlay86 » Thu Oct 24, 2013 9:39 am

This looks interesting. Reflash the pic and make an open source MAF...

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Re: What's inside the knock off LS6 MAF's

Postby The1 » Thu Oct 24, 2013 10:07 am

interesting, if it's software limited and we can mod the code and ramp it up to handle upto 16226hz then we got a match lol also the factory item has silver delphi badge.

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Re: What's inside the knock off LS6 MAF's

Postby festy » Thu Oct 24, 2013 10:53 am

That looks surprisingly well made for a cheap knock off :wtf:

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Re: What's inside the knock off LS6 MAF's

Postby delcowizzid » Thu Oct 24, 2013 10:54 am

MAF hacking 101 LOL i now want to see custom code in that maf hahaha
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem

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Re: What's inside the knock off LS6 MAF's

Postby The1 » Thu Oct 24, 2013 11:04 am

not a one off either, same issue with another 2 cars myself as per my post in enhanced thread.

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Re: What's inside the knock off LS6 MAF's

Postby DavoF » Thu Oct 24, 2013 12:23 pm

Would be interesting to see what is in a genuine MAF. :?:

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Re: What's inside the knock off LS6 MAF's

Postby tav » Thu Oct 24, 2013 12:58 pm

I was thinking the same too... dump the code from the pic via ICSP and see how it works and re-assemble it with custom features :P

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Re: What's inside the knock off LS6 MAF's

Postby delcowizzid » Thu Oct 24, 2013 1:06 pm

haha internal maf translator with dip switches
If Its Got Gas Or Ass Count Me In.if it cant be fixed with a hammer you have an electrical problem

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Re: What's inside the knock off LS6 MAF's

Postby tav » Fri Oct 25, 2013 10:53 pm

I got my genuine LS6 MAF in the post today. Here's some pics of the genuine vs the knock off:

Back View (Notice how the genuine has a silver "Delphi" engraving which the knock off doesn't have. Also take a look at the Delphi part number engraved in the plastic right under the DELPHI logo. Btw the knock off doesn't have that brown rubber thing, that's something I added to convert the 3.75" to 4" OD to use with a 4" straight)
Back.jpg
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Front View (Notice how the Knock off has a white sticker here and the genuine one doesn't)
Front.jpg
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Knock Off Hot Wires:
Knock Off Hot Wires.jpg
Knock Off Hot Wires.jpg (1002.64 KiB) Viewed 3939 times


Genuine Hot Wires:
Genuine Hot Wires.jpg
Genuine Hot Wires.jpg (760.38 KiB) Viewed 3939 times


Edge of both MAF's: (Notice how the genuine one has a Bar Code and the Knock off doesn't)
Barcode Missing on Knock Off.jpg
Barcode Missing on Knock Off.jpg (790.25 KiB) Viewed 3939 times

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