I was wondering if anybody had ever done this to an Rx7. A buddy of mine has an older 300 with his AFM mounted inline to the front mount. Does anybody know if this gives you any kind of advantages?

 

i see it in japneeese magazines all the time

 

I don't know about advantages, but it for a RX-7 setup it would be problem matic. When the TB closes and the pressure in the intercooler piping is released there is a pressure wave created. The could affect how the AFM closes.

On his 300 the AFM might be of the heated wire type, where the air flow is calculated by the change in temp accros the heated wire. For 2nd gen 7's the AFM is a trap door type where a Flap is opened relitive to the air flow comming in.

 

There was a post about this not long ago...You should search for it.

If I remember correctly though, it doesn't show any significant, if any, power gains. It's still a flap-style mass air sensor, so it's not going to free up any air anywhere you put it.

 

Well. As long as the BOV is after the AFM(meaning in between throttle plates and AFM) then it should be ok because the BOV will remove that pressure wave.

It may be there but probably smaller.

 

Yeah being a flap style it wont do much just give you bad readings from the flap being constantly open under boost(much easier to force the flap open than to suck it open) not to mention a boost restriction. on 3000gt vr4's and dsms you can do this its called blow-thru metering you have to use a gm style air meter and a signal converter. I dont know how hard it would be to make the signal converter for the 7's air meter though.

 

FYI the early 300 Z's do have the wire style AFM or whatever that style is called. I would assume the later ones do also. Interesting idea, but what purpose or advantage would it serve?

 

Easier to blow it open than suck it open and therefore the flap will always be open and give bad readings? You've got to be kidding me! If the engine is running, it's always open. Airflow is airflow and the exact same amount of air is always going through it. Having said that however, the amount of space that air takes up is different before vs after the turbo. A boost restriction??? Remember that a turbo slows down the air in order to compress it. It can't compress it if it doesn't slow it down. When the air is compressed, it takes up less physical space. If it takes up less space, you can get more through any passages that it travels through with the same amount of restriction. Translated to the afm location, this would mean that it is actually less of a restriction after the turbo than it is before the turbo since the air going through it is now compressed to take up less space. If it is a boost restriction after the turbo, it is a much bigger nonboost restriction before it. Do not place the afm before the intercooler though. It must go after it. Lots of people have run them after the turbo with very good results. Of course the best thing is to not have the need for one at all but after the turbo works just fine.

 

https://www.rx7club.com/showthread.p...converting+afm

read that.

 

pushing air and pulling them are a little different
this is probably why you keep saying it is opening all the way
because you are using it wrong

 

i want to do this to my rx7 since i have a greddy FMIC and having a hesitation issue even after much troubleshooting.

note that you can only move the AFM of a S5 and NOT a S4 since the S4 have a flap type AFM.

i have not thought about the BOV position but
i would keep it between the turbo and the intercooler.
i want my AFm between the IC and the Throttle body.

 

It has already been asked, but I don't see a clear answer. What are the advantages of a blow through system? I have seen a write up on how to wire the S5 AFM in an S4. If the S5 AFM can be run blow- through then would this be worth doing?

 

well think about it... you could mount your intake right at the turbo. wouldn't there be a advantage to that?

 

https://www.rx7club.com/2nd-generation-specific-1986-1992-17/afm-after-turbo-178739/

 

Hmmm I thought it was OK to Use the flapper Type as long as it's mounted FLAT w/ the black silicone sealed side facing UP!

 

i would run 2 BOV if i used flap type cause the flap would shut as you let off the throttle.

1 BOV between AFM and Throttle body
and after the turbo before the IC.

 

If the S5 AFM was used, wouldn't I be able to vent my BOV w/out the idling issues it usually causes? I was thinking I could put the AFM between the BOV and the throttle body, that way if the BOV leaks at idle it would have no effect.

 

i would believe that would be true...
but if you should not have idle issues because of your BOV.