jahoo88

Has anyone relocated their AFM to after the turbo? Does the spring tension need to be changed at all? I know that many people have done this in Japan so if anyone knows how its done id appreciate some input. Im going to do this to my car but im afraid that the pressurizd air after the turbo might affect the readings of the AFM. I hit 82% Airflow right now on my safc so after i relocate it, if everything is working right, i should be getting the same 82% or slightly more (bigger tid).

crackheadmel

I dont belive you would modify it at all, you just have to re-adujust the safc because it will be reading the air differently



On a side note, have you considered the damage the afm could substain from being subjected to the heat of the compressed air?



where after the turbo are you moving it to? after turbo? after intercooler? just curious

jahoo88

I moved the afm today to right in front of the throttle body. After the BOV and intercooler. The intake temps shouldnt be too crazy and driveability is much imporved now. I did notice about 10% decrease in afm opening now that its after the turbo. I turned up the safc setting by 15% under boost and turned down my boost until the Innovative LM-1 gets here.

hazard80

curious too, why would you do this?

roadkill669

Same here.

hazard80

I was reading a hpi mag last night, it had the 'Garage Saurus' s14 silvia, full circuit race, and it had relocated afm after the intercooler, didnt say why though



"After the intercooler the charge air passes through a huge Infinity-type airflow meter and back to a huge custom plenum..."

TheCamel

this is a common practice in Japan acctually, the AFM before the turbo is considered a restriction, and the airflow can be altered, so they run an open face turbo and replumb the AFM after the turbo, it acctually meters the air better, and is not prone to false readings as much as before the turbo. There have been a few tests run in Option magazine to this, and there is a noticeable dyno power difference by doing it.

roadkill669

and there is no restriction when its after the turbo

jahoo88

There is less restriction after the turbo. Both before and after the turbo the same volume of air passes through the AFM "door". The difference is that after the turbo, the air is compressed; the molecules of air are squeezed closer together, so more of them can fit through the AFM door. This is how i see it anyways and the lower percentage of AFM door opening seems to back this up.



Another good thing is that i blew a hose off at 10 psi a few blocks away from my house. I was able to get home safely because it blew off before the AFM Try that on a car with an AFM before the turbo.



Also, the car doesnt get rich and hesitate/jerk between mid throttle shifts and when i let off the throttle (mostly did this at mid throttle, never at WOT) with an atmosphere vented BOV.

roadkill669

I was boosting 15 psi and never had a problem with it hesitating or jerking, even with my type-s BOV



If you are getting a lower percentage of the AFM open, then that means that it is closed more, so less air is able to flow through, therefore, more restrictive and your ECU would see that you have less air so it will lean it out more. I assume thats why you have the SAFC to correct that.



And I am also curious, where is the room to mount this beast.