AFM vs MAP on 3T-GTEU

[GasedT18]

Hi all,

I've done a search but there's little perhaps because there is little in it.

Can anyone enlighten me as to the pro's and con's of AFM vs MAP. My newly acquired 3T-GTEU came without an AFM and I'm told the Microtech ECU that was used ran a MAP sensor (it's an antique ECU - that will be upgraded in due course).

There's one benefit I can see and that with MAP there's less potential for restriction in the inlet air flow. Another benefit I read is that it makes for a less clutered engine bay and allows more flexibilty in fitting filters.

There's only one potentially complicating factor and that I would like to blow LPG/Propane some of the time.

D

[LeeRoy]

Map also allows you to run a BOV if u wish (but this would be off street of course wouldnt it since theyre illegal). This is cause your not metering wasted air.

Other than that im not too sure of the great benefits but an internet search should be your friend here.

- LeeRoy

[thechuckster]

MAP is better (less restriction because no flapper-AFM) unless you are running ITBs then metering for the MAP becomes problematic (but solvable).

Newer hot-wire/karmen-vortex AFMs are not a flow impediment but some get confused from excessive turbulence or low air-speeds.

Being gas-powered means no AFM. period.

you only need an ignition-only ECU for gas anyway - so maybe the microtech will be all you need.

[Toysrme]

AFM is much easier to setup and tune. It also has a much easier time transitioning the engine, and dealing with airflow changes as the airflow is not interpolated & roughly guessed at like speed-density (map) is.
AFM's have very little restriction. They pose no more of a restrictionn than high-end, larger MAF's do.




BOV's can be run on MAF/AFM systems. You simply have to blow through the meter instead of sucking through it.
Which in itself is a great idea. It gives your ECU a chance to see the *actual* amount of charge entering the engine.Doing so is the msot accurate way to meter airflow entering an engine.






AFA what kind of restriction does the large AFM pose?
An AEM + MAP 3s-gte tuned. Ran back to back with & without the AFM installed.