MAF: Which to use for what application

[heptone182]

I like how you're cautiously approaching modifying your car and trying to understand how and why things work the way they do.

The ratings for the MAFs shouldn't be an issue because you're not sending accurate airflow information to the ECU anyway. The difference between a 19 and a 24lb MAF is the difference between an extra click or two to the base knob on the ARC2.

Thanks! Yeah I am be VERY cautious for that reason exactly. Sure there's a bit of experimentation, but nothing too outrageous without knowing how things work first. I went ahead and put in the 90mm svt MAF and am going to leave the granatelli one out just because I notice the screws holding the sensor seem to get loose. Maybe it's just mine but I feel safer knowing the turbos aren't going to eat my sensor for lunch! I'm sure lock tight could work but I'm just gonna stick with the 90mm. Oh and if you cancontribute to this thread, please do!!!>>>> http://www.3sgto.org/f104/official-a...ead-10114.html

[TurboSinceBirth]

Few points:

*You can NOT leave the ARC2 unit zeroed out with the flash ECU. It's not like the MAFT which sends a calculated modulation based off the sensor voltage. You need to tune the frequency. Not sure why they set it up that way.

*You can tune the timing, injector scaling/latency tables and just use the ARC controller for real time tuning. You may not even want to touch the fuel map. In fact, I see most people going this route with the flash ECU because you can't tune the flash ECU live. This is how I tune all ARC2 and MAFT cars with the flash ECU. Works great. Check out Toni's dyno thread.

*Both the ARC and the MAFT give you consistent results with the simplicity of tuning with the 4 basic knobs. Set the mid to -7 and tune the others like you would with any other setup. With the MAFT, tune the base knob and leave the rest alone.

The trade off is the ECU won't know the exact airflow so this may cause headaches for ECU controlled boost/ fuel cut at first, but you can still tune it. It's all a matter of taking logs and adjusting the tables based on the airflow the ECU is seeing.

*If you tune the motor so that it all falls within the compensation range of closed loop, there should be absolutely no reason why your tune will drift. These Hotwire ford and GM MAFs are all relative sensors. NOT absolute like our Karmen Vortex meters. You really don't need air temp/ baro compensation because your base signal coming from those MAFs are already compensated.

IN FACT you don't even need to hook up the temp and baro signal wires from the MAFT or the ARC with the flash ECU. Just disable the CELs and the ECU won't adjust the load calculation for those factors. Two less wires under the dash you need to worry about!

So if you want to run the ARC-2/flashed ECU combo would I set the mid to -7 and the rest to zero? I was going to have the flashed ECU do all of the injector scaling/latency values, timing, and fine tuning on the fuel map. The ARC-2 would be there to use the Ford MAF sensor. I could use the ARC-2 for real time tuning but I'm not sure if I would necessarily be using it for that except for maybe small changes in ethanol content say if I got E85 but it varied from 70-85% content. Otherwise, I would just use a 91 map and E85 map. I don't switch fuel often enough where it's a pain to carry around my laptop so that's no problem. I guess I'm trying to fully understand how they work together without actually trying it physically yet. I'm sure it will make more sense once I get to play around with it.

This is why I gave up on it. There's literally nothing holding those delicate screens in place. It's very easy to pop them out. The metal is like tin foil.

I figured as much. It's sitting in my closet and I may just get rid of it. If my power level wasn't as high I'd run it for sure but now it doesn't sound like it's worth my time chasing. I like the fact that you change two values and you're done with it. We'll see what happens in the future with the flashed ECU development. I sincerely appreciate everyone's efforts on it for the past few years. This is a huge development for our platform.

[Greg E]

So if you want to run the ARC-2/flashed ECU combo would I set the mid to -7 and the rest to zero? I was going to have the flashed ECU do all of the injector scaling/latency values, timing, and fine tuning on the fuel map.

No I'm sorry. I didn't say that correctly. You still need to tune the other 3 dials but you'd start off with the settings as if you still had stock fuel injectors. Since your injectors will be scaled properly, the base knob can stay closer to zero.

[Greg E]

BTW, switchable maps are in the near future.

[TurboSinceBirth]

No I'm sorry. I didn't say that correctly. You still need to tune the other 3 dials but you'd start off with the settings as if you still had stock fuel injectors. Since your injectors will be scaled properly, the base knob can stay closer to zero.

Ah ok that makes sense just wanted to clarify.

[Nater3kgtVR4]

BTW, switchable maps are in the near future.

Are you talking on the fly? Or maybe interpolating between an E85 and Pump gas tune based on Ethanol content. The later would be equal to a ProEFI setup or AEM Infinity setup. That would be amazing for our platform.


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[Greg E]

Starting with "on the fly" switchable maps using the active exhaust switch.

Later on I was contemplating an ethanol sensor input and reprogramming the current octane feature to use that sensor instead of the knock sensor. This way your high octane map would be your ethanol map, the low octane map would be the pump gas map. The sensor would deturmine interpolation between the two.

[Nater3kgtVR4]

That is very cool. I will start with your V2 for now on pump and wait for those changes later. Donating along the way

Keep up the great work and thank you so much.

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