I read a thread about locating the AFM post-turbo and believe this will solve my problem I posted in an earlier thread (eliminating AFM with Emanage) but my question is:

The thread - https://www.rx7club.com/showthread.p...light=AFM+swap
they talk about how much boost the AFM could handle, but never got specific.

Now - were the posters talking about doing this swap on the stock turbo? because I am running TO4-S and more than likely approaching 18-20psi......does anyone know how much boost the AFM can handle? or am I going to be the one posting an answer to this?hehe

edit: Im sure it will hold something, but I just want to know if anyone who has done the re-location mod popped the stupid thign after 10psi or something...

 

The question isnt "How much boost can it handle"

The question is "How can I stand having a nice turbo setup and forcing it to pump through this insanely restrictive AFM?"

The S4 AFM is found on MANY MANY vehicles, not just the RX-7. It's a pretty roadbust little unit. I seriously doubt you'll pop the thing.

 

what will your flow or, CFM be? Cubic Feet per Minute. what you are talking about with "boost" has to do with pressure. this does not matter to the AFM because the AFM will always be in vacuum. If you'd like i can vacuum test to AFM but I'm certain that the AFM by it's self will be able to be pressurised or placed in a vacuum of 50psi static.

you need to know the coeficient of flow through the afm and in order to do that you need the area of your opening and some physiscs I'd rather not get into right now. you will always be dealing with some form of Venturi effect.

so in short your AFM will always be restricting you intake, however after all of my rambling i cannot tell you when (at what boost) you will restrict your intake excessively.

sorry I cannot help more,
Ryosuke

 

I've seen this "insanely restrictive" unit in place on cars that dyno'd over 330 to the wheels......thats plenty enough for me.

But thanks for the answer, I was just concerned because in the thread I was reading NZ was saying something about the cover for the electronics popping off...

And how I can stand pumping air through the AFM with a nice turbo setup is to keep as much of the stock functions as I can - the car is a very very clean S4 with 116,000 KMS, most people would consider the full T4 turbo goign too far on a car this clean......so full standalone wasn't on my agenda, otherwise I wouldn't be carefully figuring methods to keep all this junk.

 

no my question was about PSI, not flow. As in - the AFM is designed to handle vaccum...but at what amount of pressure will its welds/fasterners/seals let go....not about flow.

I understand that it *may* be restricting somewhat but frankly the turbo and fuel will still get my 325whp goal done regardless, so...meh...

 

in that case, your S4 afm is fairly robust and there should be no problem. like i said if you like i can vacuum test mine to -50psi (limitations of equipment) and post the results but I am sure it will be fine in excess of the -50 mark.

sorry about the confusion,

Ryosuke

 

right on - thank you