MAP/AMF???

[surfingdrums]

excuse the Noob question, but what is MAP, what is AFM? what's the difference? what are the advantages/disadvantages of each?

thanks for any input

[Ryo]

From my noob telling experience i was having 2 hachis with MAP and now i have one with AFM. I think MAP was better but its just my opinion.
Some tell proper set AFM has advantages but i see on engine that i have a lot more stuff on it. Cant proper exactly tell what is the difference i see it in response of my car but maybe i have somethink different set or wrong.
Simply tell my car was running faster with MAP. I think there might be an answer for your question on http://www.club4ag.com in FAQ but i am sure one of guys here can explain it as well. I dont have much experinece with it but i will figure it out the +/- of using AFM :wink: .

[NoHachi]

AFM stands for air flow meter and thats exactly what it does, measure the amount of air going into the engine allowing the ecu to add correct amounts of fuel. 2 Styles are known, newer models use a couple (or mesh) of heated wires and calculate the amount of air by measuring the temperature=resistance drop over the wires. The AE86 uses a kind of flapper gate, where the air pushes a springloaded flapper out of the way before entering the engine.deflection angle and rate of the flapper give hints about the amount of air going in. Either way, there are some things placed in the airflow to measure it, this causes minor resistance.

MAP=Manifold Air Pressure based. Here you measure the pressure drop in the manifold resulting from the engine sucking in air. The higher the vacuum, the higher the flow, the more fuel needs to be injected.

[Bean]

according to http://www.billzilla.org/4agstock.htm the MAP versions are about 10% more powerful due to less ristriction in the airflow (better response).

As said good AFMs can give more exact information on fueling compared to MAP but IMHO a good maped (fuel,timing) MAP equiped car is better to work with especialy i.e. ITB(individual throttle bodies) setups, where you can replace the intake manifold with trumpets...

my 2p

My 86 is an AFM one and it'll stay that way until I go ITB one day

[surfingdrums]

thank you thank you thank you

[Ivan141]

Another unsubstantiated rumour that might have something to do with the differences between map and afm engines: Some here say that the old euro bluetops with map sensors have higher compression than their AFM sensored counterparts (like the US cars, and maybe Swiss cars where the emission reugulations were tighter).
Cant say for sure until someone compares pistons.

[dreja]

In one of the previous posts I compared the piston part numbers of my Swiss AFM bluetop and Knudsen's car (MAP EU spec).

Piston part numbers are different, but all other parts (piston rings, block, head, valves, etc.) are the same.

So the MAP sensored car is more powerfull, but not because of map sensor, but because of different pistons (higher compression). This might explain why people on club4ag say that it is useless changing just sensors and ecu ( AFM to MAP )...

[NoHachi]

Quote:As said good AFMs can give more exact information on fueling compared to MAP but IMHO a good maped (fuel,timing) MAP equiped car is better to work with especialy i.e. ITB(individual throttle bodies) setups, where you can replace the intake manifold with trumpets...

Not true. ITB's+ hot cams are the one situation where an AFM based setup would be infinately more easy to setup and tune. I think most of the hot cammed ITB engines run TPS based load sensing, not MAP based. As its very difficult to generate consistent and decent vacuum with the short trumpets. Either way, AFM would result in better fueling at the cost of slightly less power.

[Ryo]

Well i can tell you that i dont think i have better fuel consumption on current coupe with AFM i think the results where the same as on my old MAP version coupe.

[Ivan141]

It's not about consumption, it's about emissions.. Theoretically higher compression is better for fuel consumption and power, lower compression is suitable for a wider range of fuel octanes..