$100T2

iTrader: (1)

I would like to do the TID mod, and it seems easier with an s5 AFM...

SDrotary

I am doing the same with my N/A, it should be done this week..

Rxmfn7

iTrader: (4)

You're making a turbo inlet duct for your N/A??

mac_dad6

i think he meant he's putting an s5 afm on his s4 na. and yes this is possible but i dont remember where thewiring diagram is for it, sorry

NZConvertible

It's been discussed many times. It can be done, but there are no gains and possible problems. The TID mod is no different with either AFM, since they both have the same 3" outlet.

boosted1205

iTrader: (9)

I'm not sure if it can be done and I've heard it being done. As NZ says, there is NO advantage to swapping AFM. There's no power gain. The only thing that an S5 AFM has is it doesn't have the damn flapper door as in the S4. You cannot mount it other than level. The S5 can be mounted any which way since it doesn't have a flapper door. But, I've yet to see it work. Some have tried. I think the voltage reference is off. I'm sure someone will chime in.
And...this has been discussed for years.

SDrotary

How can there not be a power gain without the flapper door , it seems like getting that out of the way would give a few horses. anyone ever dyno before and after? yes the voltage is diff., we have a guy who makes engine harness for dune buggies and he can rewire my setup..i'll let you guys know how it turned out.

NZConvertible

I guess you've never actually seen how the S5's AFM works?

Instead of a flap, it has a cone inside it that slides backwards when you push on it. The more air flowing around it, the further back the cone is pushed back.

The point is they both work on exactly the same principle. You stick something in the air's way, and see how far the air pushes it out of the way.

I doubt the S5 AFM is any less restrictive than the S4 one, especially considering its inlet is 10% smaller!

SDrotary

Thanks for the info NZConvertible, I had seen a few early miata's switch out the flapper and pick up a few ponies, just trying to squeeze a few more from my N/A.

silverrotor

iTrader: (1)

https://www.rx7club.com/forum/showth...&highlight=afm Although for a NA.

wozzoom

I've been running the s5 alternator on my 86 for about 2 years now... No ill effects.

Last week on the dyno, we tested the S4 and S5 afm's back to back. The winner is? The S5 AFM by 1 RWHP.

The wideband showed the S5 AFM made the car run leaner, but not by much.

SDrotary

1 RWHP guess i'll use my S4 AFM.

$100T2

iTrader: (1)

The main reason I want to use the S5 AFM is that you can put a cone filter on it and I can get rid of the stock airbox... I don't think you can use a cone filter on the S4 AFM. True?

SDrotary

you can get a adpater for it

SDrotary

you can get a adpater for it, so you can use a cone style K/N

turbocajun

I have my S4 AFM angled in an upward position (intake end up)and have never had a bit of problem with it. What are the symptoms if the AFM is not level?

Icemark

tends to run rich or lean depending on how much of an angle.

Rizla+

I made a couple of search too concerning that S4 to S5 afm switch and there is something that bothers me, is the voltage reference off or not ? If so by how much ? Do someone actually tested it ?

ilike2eatricers

Does this apply to the s5 as well?
What determines if the car will run rich or lean, angle up or angle down?

Evil Aviator

The voltages are listed in the appropriate service manuals. The temperature sensors are all the same, but the flow meter voltages are different. You can look it up on the online manuals here:
http://www.iluvmyrx7.com/

Yes, it's a whole $20, and it is certainly easier to install than an S5 AFM and associated electrical band-aids.
http://66.216.67.51/product.asp?0=214&1=319&3=553

Icemark

No, the S5 AFM uses a cone style metering body, it could care less if it was mounted pointing at the moon or at the driver sidesways from left.

Frankly, that is the only real improvement in my book, I personally feel the S4 flapper door set up is a better metering body (as did Mazda when they kept the S4 flapper style in Miata and Toyota used the same flapper for the Supra for the longest time).

ilike2eatricers

Thanks for the quick reply. My airbox that I made angled the AFM a little downward maybe 5 degrees.

boosted1205

iTrader: (9)

It depends how much of an angle. When I had the IC installed, I had to somehow re-route the AFM (S4). A somewhat angled mounting of the AFM made the car bog and have a fit when the throttle was floored. A very slight angle was fine but I had to play with the angle until it was fine. It now sits at a moderate 5+- degrees. It doesn't have to be **perfectly** level. When angled, the spring loaded AFM door tends to give way to gravity but not so with S5 AFM as Icemark says, it could be even pointed at the moon

Rizla+

Hmm, not quite sure.
I did check the FSM before posting. You are talking abouth the resistance in ohms, not the output voltage.
Ok, the resistances between connectors are different. On this I totally agree due to the fact that the mechanical way of metering the flow is different. But, if you look further, in the control unit section, the voltage mesured at the ecu is the same. (Both 4v with ignition on and both 2.5-3.5v on idle.)
Maybe I did not expressed myself correctly. The real question is : does the voltage reference seen by the ecu the same with both AFMs ? Is the voltage responce curve of the flapper style the same of the cone style ? For the same amount of airflow, will the voltage output be the same ?
Or maybe it's just me who doesn't understand ****...
anyway...

NZConvertible

Who cares? It's already been posted that you only get 1rwhp peak (more than the dyno's error), so it's not worth even thinking about swapping.

One disadvantage nobody's mentioned is that if you swap to the S5 AFM you lose the safety switch that cuts the fuel pump in case of an accident. That might save your life, so it's worth keeping.