AFM Relocation Procedure

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AFM Relocation Procedure

Post by ETDOSE » Sat Sep 09, 2006 2:36 pm

I made this for another forum. Might add to the other one..

Here is one of many easy and cheap performance mods that anyone can perform on their car. The Air Flow Meter Relocation gives better throttle response, and more correct air flow readings for the ECU. This is because there is less length that air has to travel in pipes, and that because the AFM is located closer to the point of which the measurement of air is more crutial for engine performance.

For those who dont know, the AFM (Air Flow Meter) is a delicate instrument which calculates the amount of airflow being drawn into the engine. On a N12 ET and Exa, the AFM is located just between the air filter box and the "log" which sits under the Throttle Body and next to the injectors, next to the left shock tower in the engine bay.

From this position, air has to be drawn from the air filter box, through the AFM, through the 'log' and make its way to the turbo for compression.
The idea with the AFM relocation is that the Air flow meter is relocated to infront of the turbo with the end result being the turbo, a bit of pipe then ur AFM and then an aftermarket filter such as pod etc.
Although this all sounds good, it makes the 'log' redundant which is a problem which can be solved in 2 ways or so.
The log consisits of sensors for idle, and because we do not use the log in the AFM relocation, these sensors do not get a reading, or do not get the reading they want, and hence in start up people experience a rough idle for 2 mins or so.
1. First way is to stick it out, wait for the rough idle to go away after 2 mins or so, and
2. Secondly, this step wil be covered in the actual procedure.

So, you want to know wat to do already!! ok here it goes... and remember, IF YOUR HAVING TROUBLE DONT DO THINGS AT YOUR OWN WILL, always ask someone from the forums or myself, we are here to help you!

Tools needed:
-various screw drivers
-after market POD filter
-socket set
-knife such as stanly knife
-electrical tape (pref black)
-cheersquad would be good (DAM!!!)


Locate the AFM and disconect the hose clamps. One is connected to the log end, and the other is connected to the air filter box. Disconnect the AFM as well, there shuld be one plug going into it. Once this has been done, HANDLE IT WITH CARE it has many small electrical instruments inside which can be easily damaged, so go sit it on a shelf in the garage for later.


As we do not need the stock panel filter and air filter box, it is highly recommended to remove these items from the car as they no longer play a part in engine perfromance. This is done by 3-4 screws which affix to the side of the shock tower and the front (behind the headlight).
DO NOT THROW AWAY! It is even more important to keep stock items incase you need them in the future for either selling the car or to clear defects etc.

If you have to......take a break.......girls.....pfff...


Now here is a more tricky part. Because the AFM is located from one side in the engine bay to the other, the plug for the AFM in its stock position will not reach the AFM in its relocated position. So to make this work out, the loom has to be semi pulled apart and then wound back up.
From where the plug for the AFM is, the bunch of wires and loom that it is conected, or rather bound to, contain injector wires, idle sensor wires and a couple of other things. Unwind the loom and chase the AFM wire back to the other side of the engine bay, to where abouts the gearbox is. Now, what you have unwinded tape back up with the electrical tape in a neat fashion. Its best to keep it neat incase you ever decide to sell the car, hence black tape etc.
When the AFM is in place the AFM plug shuld be connected back up to the AFM.


Remove the stock turbo piping which runs from the intake on the turbo to the other side of the log. This is also done by losening hose clamps and pulling off.
You might have to get pipe made up, or if you can find some, get some pipe (stainless is preferred as it does not rust) and rubber hose joiners, most of which that you have taken off already, can be used again, and measure how long you will need, considering the length of the AFM and Pod. I would agree that you should aim to have the pod sitting somewhere behind the headlight or, if you want, experiment and have it bending down towards the ground for CAI, but remember the AFM is delicate and would not like water and dirt, stones etc hitting it.

So you want, in this order...
Turbo, pipe, AFM, pipe, POD.... and in between each, hose joiner and hose clamps.


This is where I tell you about step 2, to overcome the rough idle on startup. Since the log now has two open ends, and the sensors need readings to accomodate fuel etc for the rough idle, we have to block up the end where the AFM came from. There are a couple of ways to do this using jar lids, tin can ends, tennis balls?? and rubber. Either way, you want maximum sealage, so using a sealant like silcon will also help. Once this end is blocked up, the same has to be done on the Gearbox side of log, although this time we need a hose joining nipple (what ever you want to call it) attatched to the center, for a hose to clamp onto. Using any type of hose, even garden hose, join it to this nipple and run it to another nipple somewhere between the turbo and AFM. This is to create the absence of vaccum in the log, and hence will give no rough idle on start up.
For me i would not care, and would therefore miss this out. It kinda is a good thing, will make sure you let your car warm up etc.

So if you decide to have a rough idle, or to not, either way once engine has warmed up the car will perform fine, so I am told.


The AFM relocation is more or less complete!!! (happy dance)
Just be sure, go over everything and check its all good.

If you experience rough idle, wait it out, if not, your sweet.

You should now have better perfromance, throttle response and better fuel economy.

Hope You all enjoy!!




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Post by boost_truck_racer » Mon Sep 11, 2006 11:27 pm

Its good but a couple of pics would make the hole process alot clearer

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Post by angel » Tue Sep 12, 2006 12:35 am

you can also just relocate the log along with the AFM, that way you still have your cold idle.

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Ben Hewitson
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Post by Ben Hewitson » Tue Sep 12, 2006 8:17 am

you could just get an EGI manifold and do away with the log all together.

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Post by angel » Tue Sep 12, 2006 9:35 am

Ben Hewitson wrote:you could just get an EGI manifold and do away with the log all together.
if your talking about the one you have ben, well they are hard to get, i have some guy tracking me one down this moment and hopefully i can get it shipped over from NZ by the end of the month. unless you want to sell me yours

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Post by boost_truck_racer » Wed Sep 13, 2006 11:08 am

log is a piece of crap and is not needed for fuction of the vehicle

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Post by Kimmo » Sat Nov 24, 2007 7:24 am

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