GM 85mm MAF
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GM 85mm MAF Does the GM 85mm maf require any special tuning on an f-body? I currently have the SLP 85mm installed but would like to go to the gm. Any tuning table required to tune it in with hptuners?
It's the same MAF. Starts out as GM Delphi MAF. But then... SLP solders in a resistor to modify the stock calibration. You can see it inside. You can remove this, and it will be calibrated just like a stock one..
You will also need to reprogram the PCM for the MAF to read right with a non modified 85mm MAF. The stock calibration in the PCM for the 75mm unit is different.
steve
You will also need to reprogram the PCM for the MAF to read right with a non modified 85mm MAF. The stock calibration in the PCM for the 75mm unit is different.
steve
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How do you safely remove the resistor and how will I know if I am removing the right thing? Do you know how exactly to modify the tune for the MAF or know where to get the table for it?
If you take out the resistor you will need to reprogram.
Otherwise it's "close enough" (accorfding to SLP). All
you need is a decent soldering iron and a tweezer or
needlenose pliers or just a bent piece of wire. Here is
the critter:
Otherwise it's "close enough" (accorfding to SLP). All
you need is a decent soldering iron and a tweezer or
needlenose pliers or just a bent piece of wire. Here is
the critter:
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Ok, I just got one removing it. I basically just pulled it off with a pair of needle nose plyers. I am not sure if that was the correct way to do it or not. Some of the soldering is still stuck on the MAF and I don't know if this will be a problem. The car did some weird cycles for a while but seemed to compensate. I can definitely tell it has richened up the car quite a bit.
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The car is now officially a SLUG!! It is sooo damn slow. I guess the richness is killing all the power. I unplugged the MAF and ran it down the street and it woke up for sure! 
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From: Tranås, Sweden
Originally Posted by LS1BlackBird99
The car is now officially a SLUG!! It is sooo damn slow. I guess the richness is killing all the power. I unplugged the MAF and ran it down the street and it woke up for sure!
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Originally Posted by LS1BlackBird99
Sd mode??
for decades cars ran without MAF sensors... there are still a few new cars that dont have them either... and almost every aftermarket setup is Speed density.
basicly if you know the pressure in the manifold (the MAP sensor) and you know the temp of the air (air temp sensor) and you know the VE of the engine, you can calculate how much air is going into that cylender that instant...
in otherwords, your car runs just fine with no MAF sensor...
i like SD... nomatter what my avatar says...
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From: Memphis, Tennessee
Oh yea, I've heard that term several times. I just wonder why more people don't use SD. I know I need to use my MAF though because of my dry kit on the car. I just don't want to mess anything up right now. I definitely won't be spraying it for a while.
Originally Posted by LS1BlackBird99
Oh yea, I've heard that term several times. I just wonder why more people don't use SD. I know I need to use my MAF though because of my dry kit on the car. I just don't want to mess anything up right now. I definitely won't be spraying it for a while.
well its a choice, with pros and cons.
if you are a stock, or close to stock guy, with little or no tuning experience, and want to do a few boltons, SD isnt for you.... but if you're a guy that has a heavily modified motor, you tune everything yourself, and you will be doing things that let you use SD to your advantage, then gofor it...
personally, id NEVER spray a dry kit on a 85mm MAF.... ive had too many problems with them in the past.
just add a fuel line, fuel 'noid, and a nozzle... make it a wet shot infront of the throttlebody.
although, if you have someone whos done it before, and can tune you on a load dyno (or on a long open road) using a wideband.... then maybe.. but if you're not having a tuner with modified MAF dry nitrous experience go at it with a wideband, i woudlnt do it.. the risk seems too high for me.
again, thats my opinion.. its entirely possible to do safely, but the risk taken to tune it to that safe level makes me nervous... if you were my local friend, id try to talk you out of it, and into a wet shot or something else...
Teching In
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Originally Posted by jimmyblue
I have posted the truck MAF table that corresponds to the
de-resistored SLP MAF, very recently. Go with it.
de-resistored SLP MAF, very recently. Go with it.
Originally Posted by hen24
Is there a good reason to de-resistor the SLP85mm MAF? Why not leave the resistor in place and tune for stock MAF values?
because the SLP MAF isnt "calibrated" to work with the stocker.... instead its modifed to be "close enough"
so you would either have to make your own working MAF table anyway, for the 85mm SLP... or take their mod out, and tune it like its a GM 85mm with the tables found all over this board...
most of the tables arnt identical, but they're all very similar, and some are closer then GM had stock with their tables.
Teching In
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Originally Posted by MrDude_1
because the SLP MAF isnt "calibrated" to work with the stocker.... instead its modifed to be "close enough"
so you would either have to make your own working MAF table anyway, for the 85mm SLP... or take their mod out, and tune it like its a GM 85mm with the tables found all over this board...
most of the tables arnt identical, but they're all very similar, and some are closer then GM had stock with their tables.
so you would either have to make your own working MAF table anyway, for the 85mm SLP... or take their mod out, and tune it like its a GM 85mm with the tables found all over this board...
most of the tables arnt identical, but they're all very similar, and some are closer then GM had stock with their tables.
That MAF is an older truck MAF. I run it with the screen popped
out. This table has been good for me:
freq Hz 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1625 1750 1875 2000 2125 2250 2375 2500 2625 2750 2875 3000 3125 3250 3375 3500 3625 3750 3875 4000 4125 4250 4375 4500 4625 4750 4875 5000 5125 5250 5375 5500 5625 5750 5875 6000 6125 6250 6375 6500 6625 6750 6875 7000 7125 7250 7375 7500 7625 7750 7875 8000 8125 8250 8375 8500 8625 8750 8875 9000 9125 9250 9375 9500 9625 9750 9875 10000 10125 10250 10375 10500 10625 10750 10875 11000 11125 11250 11375 11500 11625 11750 11875 12000
flow gm/s 0.2 0.27 0.34 0.41 0.49 0.58 0.66 0.73 0.81 0.89 0.97 1.05 1.13 1.21 1.29 1.59 1.88 2.2 2.58 2.99 3.45 3.95 4.5 5.1 5.76 6.46 7.23 8.06 8.95 9.9 10.91 11.98 13.14 14.39 15.74 17.19 18.74 20.39 22.14 23.99 25.95 27.99 30.14 32.38 34.71 37.16 39.73 42.5 45.41 48.47 51.67 55.02 58.48 62.1 65.86 69.77 73.82 78.06 82.48 87.07 91.82 96.74 101.82 107.08 112.48 118.07 123.83 129.76 135.87 142.17 148.61 155.26 162.11 169.17 176.44 183.94 191.72 199.8 208.06 216.62 225.44 234.52 243.89 253.45 263.21 273.23 283.55 294.15 305.06 316.32 327.93 339.92 352.32 365.16 378.47 392.3 406.7 421.7 437.34 453.69
out. This table has been good for me:
freq Hz 750 800 850 900 950 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1625 1750 1875 2000 2125 2250 2375 2500 2625 2750 2875 3000 3125 3250 3375 3500 3625 3750 3875 4000 4125 4250 4375 4500 4625 4750 4875 5000 5125 5250 5375 5500 5625 5750 5875 6000 6125 6250 6375 6500 6625 6750 6875 7000 7125 7250 7375 7500 7625 7750 7875 8000 8125 8250 8375 8500 8625 8750 8875 9000 9125 9250 9375 9500 9625 9750 9875 10000 10125 10250 10375 10500 10625 10750 10875 11000 11125 11250 11375 11500 11625 11750 11875 12000
flow gm/s 0.2 0.27 0.34 0.41 0.49 0.58 0.66 0.73 0.81 0.89 0.97 1.05 1.13 1.21 1.29 1.59 1.88 2.2 2.58 2.99 3.45 3.95 4.5 5.1 5.76 6.46 7.23 8.06 8.95 9.9 10.91 11.98 13.14 14.39 15.74 17.19 18.74 20.39 22.14 23.99 25.95 27.99 30.14 32.38 34.71 37.16 39.73 42.5 45.41 48.47 51.67 55.02 58.48 62.1 65.86 69.77 73.82 78.06 82.48 87.07 91.82 96.74 101.82 107.08 112.48 118.07 123.83 129.76 135.87 142.17 148.61 155.26 162.11 169.17 176.44 183.94 191.72 199.8 208.06 216.62 225.44 234.52 243.89 253.45 263.21 273.23 283.55 294.15 305.06 316.32 327.93 339.92 352.32 365.16 378.47 392.3 406.7 421.7 437.34 453.69
Originally Posted by hen24
Is there a good reason to de-resistor the SLP85mm MAF? Why not leave the resistor in place and tune for stock MAF values?
Teching In
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I de-soldered 1 side(so I wouldn't loose it) of the resistor & move it so it didn't touch from where I de-soldered it. Pull the SLP sticker off & see the Delphi name.
I started using the MAF table from a Corvette Z06, tuned my VE table correct in sd mode. I got a 5.7L ls1 Holden.
I used RHS's spreadsheet to calibrate the maf, found it was OK at hwy speeds, but getting 172 left/right bank rich errors around town below 80 kph, tried to tune it out.
Ended up using the 6 litre truck maf table & found my LTFT's weren't to far out.
I started using the MAF table from a Corvette Z06, tuned my VE table correct in sd mode. I got a 5.7L ls1 Holden.
I used RHS's spreadsheet to calibrate the maf, found it was OK at hwy speeds, but getting 172 left/right bank rich errors around town below 80 kph, tried to tune it out.
Ended up using the 6 litre truck maf table & found my LTFT's weren't to far out.
