Blow thru AFM ?

[stagefumer11]

Is it possible to put the Factory L motor AFM inbetween the intecooler and turbo ? aka blowthru setup ? This would free up the turbo side and possibly take the afm out of a restriction setup ?

[Tony D]

no

[stagefumer11]

so much detail

 

So using the same style setup mazda use on their GTX famila it wouldnt work in principal with the L28et ect. ? Can the casing of the afm not be able to handle any psi ?

[AK-Z]

so much detail

 

So using the same style setup mazda use on their GTX famila it wouldnt work in principal with the L28et ect. ? Can the casing of the afm not be able to handle any psi ?

 

AFM doesn't measure preasure it measures flow. AFM measures flow of air entering the engine, now putting the AFM between the turbo and the IC, it won't be able to get an acurate reading because of the difference between high->low presure (flow) between the turbo and IC compared to the High->low presure of outside atmosphere to low presure that the engine makes.

 

With that setup, you are forcing air through the AFM, not pulling it through like with the normal setup.

[Clifton]

You shouldn't do it for the reasons already listed, but people do blow through them and hot wire sensors.

[proxlamus©]

those are MAF's then, with a hot wire sensor...

 

just to add on.. Clifton is right

[stagefumer11]

thanks for the insite. i always like detaild reasions. lol...

 

thanks

[nienberg.11]

I posed the same question before, hoping to put the afm after my turbo to accomodate venting the bov to the atmosphere (which works fine anyways). The concensus seemed to be that in addition to the reasons already named above, the afm housing can't be pressurized.

[Clifton]

It can be pressurized and has been done, it just can't measure the density of the air moving through it.

[stagefumer11]

The idea i was thinking was putting it in front of the TB. taking the AFM out of the equasion of restricting the intake. But non the less i was proven wrong. lol.

 

wouldnt the air flow be similar untill boost is reached ? with that it will be still the same fueling on full boost ?

[AK-Z]

The idea i was thinking was putting it in front of the TB. taking the AFM out of the equasion of restricting the intake. But non the less i was proven wrong. lol.

 

wouldnt the air flow be similar untill boost is reached ? with that it will be still the same fueling on full boost ?

 

If thats the case, why not use a z31 ecu and MAF sensors? You would still have to set it up with the MAF on the intake side (I believe, not to sure) but would free up some air flow by getting rid of the flapper door.

[naviathan]

If your system is properly sealed it should receive the same flow before the IC as it would after. It's like a garden hose. You get the same amount of water at the end as you do from the spiget. The IC is only meant to cool the air which doesn't make it flow any faster it just makes it more dense which the AFM wouldn't be able to decern anyhow. I would honestly recommend getting MS&S and getting rid of your AFM all together in leu of a MAP sensor. Then there's nothing in your air flow path to worry about.

[vashonz]

It's nothing at all like a garden hose. Water is effectively uncompressable, while air (a gas) will change in density with pressure and temperature. The AFM will only measure flow.

If it is placed in an unpressureized location (before the turbo) and is temperature compensated it works.

BUT if it is pressureized, then you have to take into account both temperature and pressure. I think Corky Bell talks about this a little.

If you're going to do all that why not just measure pressure, get rid of the AFM, and use VE tables?

[zguy36]

This has been done many times before. Do a search on www.turboford.org forum. This seems to be a popular thing to do on that forum. The meter can in fact measure the air flow because it will indeed have a pressure drop across the flap to make it move. I can post equations and the theory behind this if you would like, but it would be a mute point. You might even be able to find a description on turboford. Depending on how much the ECU corrects for air temp, you will be that much off since the temperatures after the turbo are that much hotter. The best way to deal with the restriction of the AFM is to scrap it and go standalone.

[Silent]

nissan afms' get pissy about 12 psi {maxima, z32, z31} they have been known to blow up at 12 psi {on the maxima, IE vq30 series} at almost 300 a pop, it gets expensive. if you are dead set on a vented bov, do a stand alone.