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| fordzatmyplace |
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Is there any difference at all in the internals of MAFs?
The reason i ask is that i just got my 75mm housing off FTG and want to know if its safe to use my original 65mm MAF internals. Also what injectors will i need to use?
_________________ ^^^ What He Said
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| Timmeh |
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You talking about the electronics?
No difference you just have to be aware that the sample tube for the heating element (which gives the input to the ECU) is the same size as the stock one, but the part where the air goes through to the engine is bigger so in effect more air is going to the engine than the ECU knows about. It could possibly get too lean a condition and hurt the engine. I bought one from FTG as well but I havent fitted it yet. What I'm going to do is organise a dyno run for air fuel ratios and fit the new MAF for that run. If it works out that the air fuel ratios are good I'll leave it but if it looks too lean I'll replace it with the stock one until I can afford the tweecer. |
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| fordzatmyplace |
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ok cheers you rick james b**ch!
what about injectors, do we use the same sort that was fitted to the T3?
_________________ ^^^ What He Said
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| xr8ute |
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The important thing to understand about a MAF is that the relationship between air mass, and output voltage is critical to the performance of your car, and is used to calculate fuel requirements as well as ignition advance.
The relationship between air mass and output voltage is stored in the computer (known as the MAF Transfer function) Now obviously when you create a Franken-MAF by mixing and matching, that relationship is different to what has been programmed in the computer and produces unpredictable results. Checking AFR on the dyno is only a very small part of the picture, because what that wont tell you is how it is working at part throttle, and transient throttle...not to mention that the computer is now incorrectly calculating load and therefore ignition advance. So it may "work", and the AFR may look "safe" on a dyno run, but it is a pretty poor way to go about things. Correct way is to get a chip burned (or Flash Tuner), with a known MAF, so that the correct MAF Transfer function can be programmed into the computer. |
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| Timmeh |
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I was planning on getting 3 dyno runs for it as you said at 1/3 throttle then half throttle then 3/4 or full throttle.
xr8ute what is the air fuel ratio that would be the minimum safest for the EFI Windsor? Anymore info you could give us would be great regarding the MAF. I'll be going from the stock 55mm unit to the 75mm unit. |
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| ovo616 |
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i've got a 75mm body fitted to mine had it on for a while now i know my a/f is up the creek think at the dyno day if was like 14.8-9? somithing like that.
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| hans hartman |
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{USERNAME} wrote: I was planning on getting 3 dyno runs for it as you said at 1/3 throttle then half throttle then 3/4 or full throttle. i thought the oxygen sensors adjusted the mixture-lean rich,the maf is the starting point,,a average mix-until it hits the exhaust and the sensors adjust it?
xr8ute what is the air fuel ratio that would be the minimum safest for the EFI Windsor? Anymore info you could give us would be great regarding the MAF. I'll be going from the stock 55mm unit to the 75mm unit.
_________________ R.I.P HANS HARTMAN |
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| hans hartman |
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{USERNAME} wrote: I was planning on getting 3 dyno runs for it as you said at 1/3 throttle then half throttle then 3/4 or full throttle. i thought the oxygen sensors adjusted the mixture-lean rich,the maf is the starting point,,a average mix-until it hits the exhaust and the sensors adjust it?
xr8ute what is the air fuel ratio that would be the minimum safest for the EFI Windsor? Anymore info you could give us would be great regarding the MAF. I'll be going from the stock 55mm unit to the 75mm unit.
_________________ R.I.P HANS HARTMAN |
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| eb2flyz |
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std o2 sensors - narrow band - only work in closed loop and are only good for 1 point either side of stoich (14.7) at the best.
also i found these interesting write ups on how MAF's work and the importance to get the right maf , it also explains the so called calibrated MAF's operation http://www.superstang.com/maf.htm http://fordfuelinjection.com/files/How_MAF_works.doc definetly worth the read for anybody wanting to change or modify their mafs |
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| Timmeh |
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eb2flyz they are good information links there but they seem to be talking about larger injectors to go with the larger MAFs.
What would happen (like I would be trying) if I got the electronics from the stock 55mm MAF and put them in a 75mm MAF as they both have the same sample tube but have different size openings for the air to the engine? |
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| xr8ute |
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{USERNAME} wrote: What would happen (like I would be trying) if I got the electronics from the stock 55mm MAF and put them in a 75mm MAF as they both have the same sample tube but have different size openings for the air to the engine? The only way to really know would be to put it on a flowbench for MAF's and map out the relationship between air mass and output voltage.
This is the problem with FrankenMAF's....you just dont know exactly what they are doing. |
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| xr8ute |
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{USERNAME} wrote: i thought the oxygen sensors adjusted the mixture-lean rich,the maf is the starting point,,a average mix-until it hits the exhaust and the sensors adjust it?
Nope, the O2 sensor is just there as a fuel trim. That means it can identify adjustments required to injector pulsewidth at cruise/idle conditions to maintain 14.64:1 (for emissions). As eb2flyz has said, its a narrowband sensor, which means its got no idea what the actual AFR is....it only knows if it is higher or lower than 14.64:1 The computer achieves a particular AFR by measuring the mass of the air in the engine, and injecting the appropriate mass of fuel. The MAF is the one and only sensor that measures the mass of the air, hence the reason why it is so important that it is setup accurately. |
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| xr8ute |
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{USERNAME} wrote: xr8ute what is the air fuel ratio that would be the minimum safest for the EFI Windsor?
I dont know personally, but the consesus seems to be somewhere between 12.5:1 and 13.0:1 at WOT for a naturally aspirated Windsor. I have heard many tuners say that a richer AFR (like ~11.5:1), where the torque curve peaks, will make more power at those rpms. I wish I had a tuner so I could test all this theory out. I'm gonna sell this AU and buy myself a Mustang with twEECer support one of these days 
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| eb2flyz |
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{USERNAME} wrote: eb2flyz they are good information links there but they seem to be talking about larger injectors to go with the larger MAFs. my advice would be to buy a good quality maf with a transfer funtion supplied and then tune it with a twEECer, to relate it simply would you trick/lie to your GF, because in the end they will find out and cause nothing but problems. the EEC is the same, you tell it lies it will find out
What would happen (like I would be trying) if I got the electronics from the stock 55mm MAF and put them in a 75mm MAF as they both have the same sample tube but have different size openings for the air to the engine? |
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| phatal |
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Age: 42 Posts: 517 Joined: 3rd Dec 2004 Ride: SZ Titanium & ZG Fairlane Location: Roxby Downs |
What's the go with an EL GT MAF with electronics totally replacing the EL2 XR8 one? Would the ECU freak out? Would you need the EL GT ECU as well as 24 pound injectors? Do the MAFs even have the same connectors?
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