I saw something about the miatas having a maf sensor, but 5 prong insted of 7. With a wiring diagram i'm sure i could swap harnesses, my main concern would be would it work with an s-afc? Would i recieve practically the same benefits of a haltech without the hastle of rewiring the car? Any help will be greatly appreciated, thank you for your time.

 

A MAF? An rx-7 has a MAF anyway, well, an S4 or 5. Do you mean MAP?

Could you use it with an S-AFC? Sure, all those things do is trick the voltages anyway.

Would you have the same benefits as a Haltech? Umm, no

 

I've got a GSL-SE, it has an afm and so do the s4 and s5. U mean same benefits as in similar horsepower gains. I really don't want to have to rewire my car if it will only give me maybe 5hp over a hot-wire maf and s-afc.

 

For an NA GSL-SE I don't think you should get a Haltech unless you have some serious plans for it. I kind of doubt getting a new MAF, AFM, whatever, will help that much either because I don't think they are a known bottleneck. I am sure they will cut some power once you hit some high HP numbers but I don't know what you already have.

 

The AFM have the flap door that from what everyone has said is VERY restrictive.

 

It's not all that restrictive. The other problems with the S4 are the restrictive airbox, and the horrible ECU. A MAF is going to be a nightmare to wire because the hot wire needs the ECU to control its temperature, which means that YOU will need to build that circuit - good luck. Assuming the same cross-sectional area, the MAF will maybe save you 1% hp if that, and even if you replace the restrictive air box with a cold air intake, you will still be stuck with the awful ECU running the engine (as best it can with your resulting Frakenstein setup). Just remember that hp gains are generally a percentage, rather than an additive quantity, so if you are running close to stock levels, your power gain will be negligible. If you really want to remove the restrictions, then get a standalone EMS and cold air intake, which will take the place of the AFM, airbox, and ECU, and will eliminate the ECU flooding problem.

BTW, if you look around the internet and see the great and wonderous performance gains from slapping some expensive MAF kit onto a car, the gains are mostly due to better tuning rather than the fine engineering of the components. The people who are trying to sell you this junk usually don't explain this part.

1) MAF now means a hot-wire or hot-film type meter, while AFM means a vane-type. Don't ask me why or when this changed. I think the vortex meter has still retained the same termininology, but I'm not sure, lol.
2) You could use an S-AFC to aid the stock ECU, but you would also need to make a custom circuit to control the hot wire, unless somebody makes such a component and I'm not aware of it. IMO the S-AFC is a band-aid, so I really don't see any point in bothering with this whole mess unless you are really bored and have a lot of money.
3) The Haltech EMS computers use the speed-density method for running the engine, so they are not really comparable to an airflow meter type of system. If you want to generalize, an airflow meter type system is good because it automatically compensates for engine wear (somewhat, anyway), while the speed-density type is good for forced induction applications because it measures vacuum and boost seamlessly.

 

I'll go with a new ecu then, i'm trying to find out all i can while building a new motor so i know what i can do before even starting and definately don't won't to go through trial and error on something as important as electronics. I just started college for the specific reason of building my motor, I start in a month though and want to get started with parts ideas now.

 

Actually, it's always been this way. A Vane-type meter measures air volume (force exerted over a surface area), and still requires a temperature sensing component to calculate air mass. A hot-wire sensor directly measures air mass (measures convective qualities of the air which change with mass). That distinction has been lost on some.

FWIW, a vortex-type sensor is an airflow meter, as the harmonics in the sensor don't change with temperature, and thus, with mass.

See my post about mass flow systems in the other thread in this section for my opinion.

Brandon
BR7 Racing