Blow Through MAF ?

90sickfox

Wasn't a pretty sight...and I've got big hands
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Mar 2, 2015
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I've been doing research on blow through maf sensors and have a couple questions for those who know. I went through a few threads about the lightning MAF. On my car I'd have to put one in the cold side turbo piping after the intercooler. Theres a nice straight 3" pipe back there.

The issue is my car should be making a bit over 500hp ( calculations say around 520 with 7 psi ). Engine itself dynoed at 425hp...331, ported TW heads, ported Holley systemax, 76mm TB, 1.6 rr, xe282hr camshaft, 42lb injectors ). Lightning mafs seem to peg at about 450- 500. That's in the 90mm housing...3" is around 76mm. Everyone says 80% less in blow through configuration. As hp goes up seems like pipe diameter also increases. That's a no go for my set up.

Im going to put a maf bung on my pipe but need help finding a maf that won't peg until at least 550hp at the engine.

CNan anyone recommend a blow through maf that will work in a 3" pipe at the resolution I need ?

My camshaft is kind of big and only pulls about 10in.hg. at idle so i think MAF would be easier and more precise to tune. ( MSPNP2 )
 
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With the MS tuning MAF is actually very easy.... My car ran the first time i turned the key and i even drove it around untuned and she did great. [for an untuned engine] even if the MAF you get pegs when the boost comes up thats not an issue, all you have to do is setup a speed density table that will take over for your fuel needs.
If the car is giving you fits tuned SD only then you can add a second modifier table based on Throttle position, and transition the two tables. This way fuel at idle/low throttle can be done with Alpha-N and once the MAP signal stabilizes the tune will seamlessly transition into SD..

When did you have the car dyno,d???
 
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Its Steve to the rescue again...I was going to say the same thing and apply table switching

This will give you the ability to make a table for idle/part throttle, and use SD for the boosted area. This will allow for a non-worry of the MAF sensor pegging due to not using it at the upper limits.
 
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With the MS tuning MAF is actually very easy.... My car ran the first time i turned the key and i even drove it around untuned and she did great. [for an untuned engine] even if the MAF you get pegs when the boost comes up thats not an issue, all you have to do is setup a speed density table that will take over for your fuel needs.
If the car is giving you fits tuned SD only then you can add a second modifier table based on Throttle position, and transition the two tables. This way fuel at idle/low throttle can be done with Alpha-N and once the MAP signal stabilizes the tune will seamlessly transition into SD..

When did you have the car dyno,d???

The engine was dynoed by the builder. The car is no where near dyno ready.
 
dont even need table switching, just set the VE2 table as multiplicative bottom row at 100kpa 100% and as the boost increases you can add fuel as a percentage, so once the meter pegs its stuck at its top row but the VE2 table keeps multiplying that last row as boost goes up.
 
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Is Steve to the rescue again...I was going to say the same thing and apply table switching

This will give you the ability to make a table for idle/part throttle, and use SD for the boosted area. This will allow for a non-worry of the MAF sensor pegging due to not using it at the upper limits.

Steve is on it man. He doesn't waste any time. Already has another tune ready for me.
 
Thanks @Boostedpimp, that link gave me what I needed. HPX it is. I'll get one ordered ASAP.

Thanks everyone. It's amazing how much knowledge this forum has...and how quick people reply. On3 has the HPX sensor calibrated for a 3 inch pipe and supports up to 650hp.

Screenshot_20190307-125151_Chrome.jpg
 
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Scott I have your tune ready... When you wire the MAF into the ECU take it into the knock or baro pin, I have the tune setup on the knock pin right now so its an easy change if you use the baro pin.
 

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  • Dusty REV 3.0.0.MAF.msq
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To my knowledge, there are no formal instructions to convert over to MAF.
How you wire it in is up to the user.
Looking at these links, they make no mention of the MAF wires passed through to AD1 or AD2.
Just because they don't mention it doesn't mean they are there or not there.
OP will have to "ohm it out".

I used spare pin holes on the Ford 60-pin (there was no pin) for the DIYPNP.
Power & ground to MAF was already there, pin-37, pin-40, respectively.
MAF & MAF Return were added, pin-50, pin-9, respectively.
MAF Return gets tied to SG on the Main Board.
Pin-50 goes to AD1 or AD2

However, these are the links to the MS2PNP.
Ford Mustang 8693 MegaSquirt Plug and Play
https://www.diyautotune.com/product/megasquirtpnp-g2-eec4a8-for-86-93-ford-mustang-5-0/
MegaSquirt PNP Gen2 Documentation
http://www.megasquirtpnp.com/docs/mspnp_g2_eec4a8.php?isModel=1
MegaSquirt PNP Gen2 Manual
http://www.megasquirtpnp.com/docs/mspnp_g2_genInstall.php?boardVer=13&isModel=2
 
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Did quick research...mspnp2 doesn't use maf out of the box....so the maf sensor on a factory car wouldn't be used....unless you do like the guru says.

I'll be wiring in a knock sensor at a later date but will wire the maf to that pin. When I get the knock sensor hooked up I'll swap pins.

20190308_130553.jpg
 
I added to my post above, refresh your screen.
I would ohm it out, because it might already be wired in part way or all the way.
MAF wires aleady go to the 60-pin (from '89-on).
The most it will take is adding 2 wires inside but if lucky 1 or 0.

Remember, this is DIY, their docs leave much to be desired.
 
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Dont worry its a simple conversion in an excell spreadsheet
TS Flow is in grams/sec.
Calibration curves can be in cfm or Kg/hr
Kg/hr = cfm * 2.004
1 Kg/hr =0.277777778 grams/second

BTW, TS tool top says:
Specifies the flow curve in grammes/sec vs. frequency or voltage.
Start out with the actual flow curve for your MAF sensor and then 'tweak' to tune it to your install.


DO NOT tweak the curve, tweak the VE table.
 
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