Afm

[mk2er]

hey guys just wondering with afm's which afm's of other cars can i replace with mine and is a plug and play

can i use a bmw 7 series afm? my mate has a 90 model 735i sitting in his backyard

[Stiggy_21]

What's afm??

[RedMk2Gti]

I guess he means Air Flow Meter.

[NeuSpeedGTI]

Hey mate..

I am guessing you are running a digifant. If so it's actually an AMM (air mass meter) meaning that runs a mechanical paddle which is connected to a eletronic strip which depending on where the paddle is sitting when air is flowing through the AMM sends a respective voltage signals to your ecu.

The AMM from the BMW will work, however being that it is designed for a larger engine and ultimately a greater air inflow the tension on the paddle will be much higher and will not open up as much as it should with our small 1.8l engines breathing as they should. (once you have a look inside this will all make much more sense!! )

To fix this is up you will need to crack open the black box on the outside of the AMM and reduce the spring tension so the paddle can move more freely based on the lower volume of air and send correct voltage signals to your ECU. This is a possible performance mod becuase it means your engine can breath better by taking in more air, however this alone will not improve performance. You will need to address the 'exhale' of your engine also with extractors and larger exhaust and of course additional fueling will be required.

I've acutally got one of these sitting in my parts box at the momment however have not got around to putting it in. You will need to put another bracket together to hold it as it wont fit in our standard air boxes plus source another air filter and the diameter of the hose connected to the AMM feeding into the inlet manifold will need to bigger at the AMM end. Way around this is a possible aftermarket option in the way of a 'Power Rohr' and a silicone hose reducer, but double check that everything will fit!!

Hope this helps!

[mk2er]

Hey mate..

I am guessing you are running a digifant. If so it's actually an AMM (air mass meter) meaning that runs a mechanical paddle which is connected to a eletronic strip which depending on where the paddle is sitting when air is flowing through the AMM sends a respective voltage signals to your ecu.

The AMM from the BMW will work, however being that it is designed for a larger engine and ultimately a greater air inflow the tension on the paddle will be much higher and will not open up as much as it should with our small 1.8l engines breathing as they should. (once you have a look inside this will all make much more sense!! )

To fix this is up you will need to crack open the black box on the outside of the AMM and reduce the spring tension so the paddle can move more freely based on the lower volume of air and send correct voltage signals to your ECU. This is a possible performance mod becuase it means your engine can breath better by taking in more air, however this alone will not improve performance. You will need to address the 'exhale' of your engine also with extractors and larger exhaust and of course additional fueling will be required.

I've acutally got one of these sitting in my parts box at the momment however have not got around to putting it in. You will need to put another bracket together to hold it as it wont fit in our standard air boxes plus source another air filter and the diameter of the hose connected to the AMM feeding into the inlet manifold will need to bigger at the AMM end. Way around this is a possible aftermarket option in the way of a 'Power Rohr' and a silicone hose reducer, but double check that everything will fit!!

Hope this helps!

yeah i looked at the 735i and its identical the reason i want his AMM bcoz comes with a k&n pod filter and alloy pipe yeah ill figure it out im a 4th year technician...and my exhaust has been updated straight through no mufflers with depleted cat...running 2 1/4 to the ass end....and with the fpr ill do something about it
but i will loosen the spring tension and ill go by 1 tooth at a time but how will i know when its perfect air/fuel ratio i dont have a meter inside the car unless i can check voltage on something to see if im running or lean...or just buy a air/fuel meter at repco

[NeuSpeedGTI]

Well an o2 meter is certainly the best way to get your mixtures right, however adjusting the spring tension alone will not solver this problem unfortunately. You will need to start exploring the idea of a replacement ECU chip advanced timing etc...

However if it is just an aftermarket filter option you are after they do exist for the stock AMM for the 1.8l. K&N do have options available that are inclusive of bracket and filter. That said I was running a an open POD style filter for awhile and to be honest other than the sound the performance difference wasnt great and after a period of spirited driving was probably even worse due to the amount of warm air that built up in the engine bay. I have since moved onto a K&N Apollo filter with a cold air intake feeding from the front bumper and this setup seems to be working well, in addition it also has a point for a vacum lead from the filter housing to connect to your FPR.