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haltech will run either. but noone buys an aftermarket ecu to run maf. unless you are a pro-m fan.
MS will run a maf as well, but 99.9% of people don’t ever use the function. There’s just no reason when sd will do everything you ever need. What I’ve heard is some people like to have maf functionality to help line out engines that make little vacuum at idle. However you can just use alpha n for that.
 

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my maf would not run a cam with vacuum at 16, nor my sd lol...........well it would for a few seconds but as it dropped, it died, but all other rpms actually ran pretty good, i just had to idle at around 900 to keep it from dying at a light, or dying when put in gear so out came the custom ground........as well as maf, waste of money
 

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Vacuum doesn't affect the maf. Sounds like you just needed to work on the tune. Specifically dashpot.
 

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my maf would not run a cam with vacuum at 16, nor my sd lol...........well it would for a few seconds but as it dropped, it died, but all other rpms actually ran pretty good, i just had to idle at around 900 to keep it from dying at a light, or dying when put in gear so out came the custom ground........as well as maf, waste of money
I’ve ran stand alone sd with a car that pulls 4inhg at idle. Damn near anything will run an engine that pulls 16.
 
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my maf wouldn't do it for some reason, NLOC guys were stumped too.
but it was a custom ground from cam research that had 32* of overlap and was ground to be run on speed density, im sure I could have got pimpx to make it run but i wasn't throwing anymore money at it. so the cam sits on my toolbox, and i guess i'll make a mailbox stand out of it one day
 

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Discussion Starter · #49 ·
I have a PIMPXS in my turbo Fox, it's still a speed density system. I like it, the support forum is really helpful. The MSPNP is a speed density system too, I've heard its similar to the PIMP and I have also heard the forums are pretty good. If you already have a standalone system in mind, I'd get the nastiest cam that you can get, considering there will be engine management at some point, and a cam swap is basically tearing the engine half apart.

Speed density system is very forgiving. The people that hate on it ain't ever rocked with it. My 85 Marquis has the most preliminary EEC-IV speed density ECM which runs two injectors on a throttle body unit. Everyone on the Marquis forums said that ECM would never handle a head swap or an intake swap or exhaust mods, and we've done all of those things, daily driving still. I'd say just throw what you got at it.
Dude what kinda numbers was your SD Marquis making HP wise? Also did you run one of those high LSA cams to keep the speed density happy?
 

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Dude what kinda numbers was your SD Marquis making HP wise? Also did you run one of those high LSA cams to keep the speed density happy?
No HP numbers but I got it to run 9.9 @ 68.9 at Irwindale. My 94 GT ran 9.0 and my 88 ran something like 8.7 so I'm pretty proud of that 9.9 haha. I'd figure its making maybe 200hp which isn't bad considering stock they make like 140hp. The cam is a stock LoPo Grand Marquis cam and yes, they have a higher LSA, something like a 115 or 116LSA. In my modifying endeavors I have come to the conclusion that the CFI unit is just an educated 2-barrel carb. The 81-83 Marquis were getting 2-barrel carbs and the 84-85 Marquis got the 2-barrel CFI units with two 46lb. injectors. It is interesting to me that the 85 5-speed Mustang GTs were getting Holley 4-barrels, and the 85 5.0L Mustangs with Automatic transmissions were getting the 2-Barrel CFI units as well but with two 52lb injectors. Another interesting fact is that the Ford CFI units have a fuel pressure regulator, which believe it or not, has the same 3-hole bolt pattern as the 87-93 fuel rails, potentially allowing the use of an adjustable fuel pressure regulator. The CFI unit uses a return style fuel system so the CFI equipped cars have an in-tank electric fuel pump. And all the 84+ CFI equipped cars were already getting a TFI distributor, MAP sensor, TPS sensor, and speed density ECM with the EEC-IV strategy. And another thing: these early ECMs have the JB3 port, which would allow the use of tuning chips like the SCT & Moates Quarterhorse. But yea, knowing all this info I just figured, hey if it doesn't work for me I'll put it back to how it was, but things have worked out cool so far. This summer I will try out the adjustable fuel pressure regulator theory and see if we can't bump up the fuel pressure at the rails. I will install a higher LPH fuel pump that I have laying around to see if that helps at all. I also have a small SUM3601 cam to try out as a last ditch effort to maximize this little CFI combo before we go with a real EFI conversion. With a MAF.
 
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F
Off the top of my head I think the WOT spark is similar, can check when I get home, but the SD are richer, and if you're mass air meter is some kind of restriction it'll make a difference too.
Forgot to check last night, but the WOT spark is identical between the speed density and the mass air programming.
RPM Spark
16383.7526.00
5000.0026.00
3500.0022.00
2600.0022.50
2150.0021.50
1800.0018.50
1000.008.00
0.008.00
0.008.00


WOT fuel multiplier is a lot different
Speed Density
RPM Y
16383.750.85
4800.000.85
4400.000.89
4000.000.85
3200.000.86
2400.001.00
0.001.00
0.001.00


A9L
RPM Multiplier
163840.945
60000.945
44000.953
38000.977
32000.945
24000.969
16000.906
01.000
 
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Amazing how low of timing they put in the ECU, I always forget they had it tuned to run piss for fuel.
 

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Amazing how low of timing they put in the ECU, I always forget they had it tuned to run piss for fuel.
Right, they don't get to full advance until 5K RPM too.
 

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when i switched to maf, i lost power, everywhere......then i installed the air adjuster from massair.com which lets you fool the computer with the maf voltage. theres a little toggle switch for manual and a small flat head pin that you turn to richen, or lean it out. worked pretty good for shadetree style tuning.......i ran it for years to solve a deto issue at WOT and smooth as butter idle......gains from the maf.............. zero.

i wish pimpshift was around when i did my maf swap so many years ago....the only thing i could get for the e4od was baumanator......which was nice and worked but left me unable to tune the engine......just the stock a9p logistics.....now you can get that stuff at walmart damne near and tune it with an ap on your phone
 

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when i switched to maf, i lost power, everywhere......then i installed the air adjuster from massair.com which lets you fool the computer with the maf voltage. theres a little toggle switch for manual and a small flat head pin that you turn to richen, or lean it out. worked pretty good for shadetree style tuning.......i ran it for years to solve a deto issue at WOT and smooth as butter idle......gains from the maf.............. zero.

i wish pimpshift was around when i did my maf swap so many years ago....the only thing i could get for the e4od was baumanator......which was nice and worked but left me unable to tune the engine......just the stock a9p logistics.....now you can get that stuff at walmart damne near and tune it with an ap on your phone
You could convert it to run the SN processor and that will run your engine, and transmission. I'd guess most would rather just get an aftermarket system so they can get tech support though.
 
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