maf
 

I just got an Its race car that I want to use some parts off of for my track day car...I really like a clean and simple engine bay similar the one in the ITS car ... I would like to tidy up the maf and cold air intake....my ITS parts car has a series 5 motor yet uses an maf like my series 4 street car....but my brother has the same series 5 motor and his uses the very small black round one....all this makes me think I may be able to use one on my s4 ,..is that possible , maybe with a series 5 ecu ?

For the most part, it is a wasted effort to concern yourself about the AFM. Which class do you race in?

air flow
 

...not a race car...street track day car only.....I like to fabricate things that will give me a clean engine bay....this would help...as long as it didn't hurt my performance I would do it..

Oh boy. Let's start from the beginning then...

When you take your car to this 'track day', what does the track look like?
A) two straight roads with a colored light thing in the middle
B) an oval
C) a winding paved road in the middle of a big stadium
D) a winding road in the forest or mountains
E) a big parking lot with cones, tires, and/or concrete barriers

....Seriously....I just want to know about maf replacements...if maf or air flow meter is the right description....Thanks for the attempt at car life advice....but just the information please :)

I don't suppose you considered the remote possibility that what I am asking is relevant?

Maf
 

...yes I did consider that ...and I am grateful for your interest in my question...but I am 68 years old with many years racing , 6th at Sebring in 92 ....club wins also all as a privateer.. so from my experience it wasn't relevant.... But I don't know in a little round s5 maf will bolt up to an s4 with maybe an ecu change and plug alteration ...how this has become a contest is also beyond me...but I am interested in the answer if you know it.....

You may or may not like the answers, but here goes:
- Yes, you can use a Series 5 AFM on a Series 4 engine and vice versa.
- Yes, you should really use the correct Series AFM and ECU so that everything functions as designed, although if you have the electrical skill and time then you can jury-rig them to function if mismatched. Why anybody would want to do this is beyond my comprehension, but to each his own. See Chapter 4 of the factory service manuals for resistances and pin-outs. Note that the AFMs for the non-turbo and turbo engines are slightly different, so go to the appropriate sub-chapter for your application.
Foxed.ca - Mazda RX-7 Manuals
- The S5 AFM is more efficient but the S4 AFM is bigger. Choose your poison.
- The S5 ECU is a better computer than the S4 ECU.
- From a racing standpoint, a modern standalone EMS is far, far, superior to any 1980s piece of junk stock ECU and vane-type AFM. A standalone EMS is your best bet for meaningful performance. Additionally, a standalone EMS makes for a very clean engine bay if the wiring is neatly installed. When racing rules allow, anybody who is serious about performance uses a standalone EMS (speed-density or alpha-n) in place of the stock system. In some racing classes it is actually better to swap the EFI for a carb. This is why I was asking about the purpose of the car. Since you do not wish to discuss this on the forum, I recommend discussing this with your racing buddies before spending any significant amount of time or money on this project. Mike Van Steenburg may be able to steer you in the right direction, although he really isn't an EMS guy himself, as you probably know.

It may have a series 5 engine but the Electronics on the car are most likely S4..so the S4 AFM is your best bet.
Personally I wouldn't go to an S5 Afm as you end up changing a lot of parts just to use THAT part..and to me?That is a pure waste of time.

thank you both for the replies..when you say you have change a lot of parts..we are getting to the meat of my question...what parts other than the afm ?

You'd be essentially changing engine harness,which differ.
The S5 engine has an electric OMP whuich needs to be "seen" by the ECU or the car goes into Limp Mode.
The S4 has a mechanical OMP,so the ecu is not involved in giving the internals lubrication.

Just the wiring alone is a Pain in the ass.

Really if your engine is an S5 then Guys can turn it into an S4 by slapping on S4 parts to make it an S4 engine..you gotta change the Front cover IF you want to run the mechanical OMP though...Unless you just Take the OMP off and premix,so you don't have to change the cover.

HERE: read this.
Rotary Resurrection home of the budget rebuild.

Styx, though your method is the proper way to convert, it has been done before with a simple hack-up of the AFM connector.

I vaguely recall there being discussion that the S4 and S5 systems/AFM were not quite a direct match, and some anomalies were observed. Regardless, the general consensus is this is a bad idea and waste of resources.

https://www.rx7club.com/2nd-generati...m-swap-177125/

The best way to clean the engine bay up is to delete everything and install a stand alone with a terminated harness, Unless you have electrical skills to make your own tucked harness.

heh,heh,..Ya ..ok...
That is also the best way for someone with limited mechanical skills to get frustrated and sell their car because it won't run correctly after such a suggestion!

A stand alone needs a Tune.With an average N/A..not really needed and money can be put to use for other things to make the car better..like suspension upgrade.
And if someone doesn't know anything about the basic mechanics of the car then they will be shelling out money to get tuned..since they probably don't know anything about tuning a Rotary engine..which by the way is not anything like a Piston engine.

The best suggestion I can give is to DO RESEARCH into the parts that are on the engine,What their function is and how the engine will react without them.
If the engine is working correctly right now and you start taking shit off the engine without even knowing WTF will happen just to "clean up the engine bay"..then you seal your own fate!

I'm not saying leave the engine alone,I am saying that People need to realize that Parts ON the engine were put there for a reason.

* and IDULEY..ya I remember the S5 AFM can be put on the S4..But honestly It's not a big Performance upgrade.
I didn't want to mention that particular suggestion as it may be out of the scope to the average New guy.I try not to put people into ripping stuff off the car or hacking into 25 year old wiring for something that in the end does not help the car at all!

but it is the best way, he did mention this IS a racecar.

Maf
 

So , essentially It is a simple rewire...you lose the fuel pump shut off at stall...and you cannot be sure that the ECU reads the air flow the same as the original...Hmmm .. I am considering this , not for a performance gain..as apparently there isn't one , but to allow me to construct a more compact cold air box pulling thru the hood , it would be fun to build it , and it would give me a cleaner engine bay.....if Its worth it ..well that's something only I could know