AFM Relocation

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The Renegade
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AFM Relocation

Post by The Renegade » Fri Jun 29, 2007 11:58 pm

I think this is the original article from Fullboost.com which now seems to have been deleted from their site. I have changed a few things and just given it a general tidy up.
Enjoy.... The Renegade

It has been asked many times. "How do you do the air flow meter relocation?" Well here we will guide you through the procedure in detail, but feel free to make your own tweaks at your leisure.

Removal.
Open the bonnet. The AFM (air flow meter) should be located before the airbox/pod filter on a bracket with 3 10mm bolts holding it on the drivers side of the engine bay, mounted on the strut tower.

Remove the Airbox/pod/whatever air filter you have from the AFM. Then use a Phillips Head Screwdriver to undo the clamps that connects the piping from AFM to the log* - See Glossary
Be gentle in the removal and handling of the AFM, There is a delicate electrical element that can be broken or damaged easily.

There is a plug on the bottom of the AFM. The easiest way to remove this is by using a flathead screwdriver and pushing the little metal holding clip outwards away from the plug.

Once the plug is away from the AFM, place the AFM in a safe place out of harms way as this is a delicate item.

Next, undo the clamps that hold the pipe from the passenger side of the log to the turbo compressor opening, and place this with the AFM.

The next thing is a little more fiddly and time consuming. The loom that runs under the throttle body beside the log, must be unwrapped as the plug for the AFM cannot reach where it will later be placed. The wrap on the loom consists of a film of tape and some rubber tubing. Keep this tubing for later tidy ups, or replace it with some new split tube corregated conduit.
The wires inside the loom consist of: Injector leads,AFM leads,cold idle sensor wires and TPS wires.

The easiest way to work with the loom is by un-plugging the TPS (throttle position sensor) cold idle sensors and trottle control screws. This allows you to hold it all away from the engine while you are playing with the loom wrapping etc, and just makes things easy. Remember to replace the plugs afterwards.

Gently ease the AFM plug through the gap under the throttle body and place it out of the way.

The Removal section is now complete.

The next section is the Relocation. But first, grab another beer...

Relocation.
The Ends of the log must be blocked by a solid item. I have heard of many different things being used here such as:
Welding an alloy cap over it.
End caps for PVC plumbing pipe.
The bottom of a paint can.
Tennis balls,
Nescafe coffee jar lids
Vegemite jar lids.
I personally have used the PVC end caps and they are brilliant. They will require heating & a rubber mallet to fit them over the log ends, but all the better to seal with, huh?
I think the welding is the only 100% guarantee that you have a perfect seal, followed by the PVC end cap, then the paint tin. Both the paint tin and PVC end caps should have some 3 or 4 mm rubber padding in the bottom to act as a gasket.
The other solutions should be temporary only as they are rather dodgy.
In the passengers side end cap you will need to install a hose fitting. Connected to this will be the hose that goes into the inlet before the turbo, but after the AFM. Without this hose, the whole project is a waste of time; it will not work.

Grab the AFM, and the pod. Use a Factory pipe joiner to attach the AFM to the Pod in such a way that water will not enter the pod. the diagram below will give you a rough outline of the placement that is required.

TURBO===O===AFM===POD

***KEY***
=== rubber joiner/steel pipe
=O= hole in joiner/pipe

If you use rubber pipe here, you will need to find one that has a pre-molded hose fitting in it. This is for the other end of the hose that is now in the end cap on the log. If you use steel you can weld or braze a metal pipe fitting into it.

* REMEMBER: The AFM only works one way due to its flap reading style. The AFM opening that has a cross on the inside of opening is the side that the pod filter attaches to ONLY.

Grab a length of heat resistant hose. Make sure the inside diameter suits your hose fittings in the inlet tract and the end cap on the log. Plug in the AFM meter, and all of the other plugs you removed earlier. Now kick her over.

The reason for the hose is to supply air (that has passed thru the AFM) to the inlet after the throttle body via the equipment that is mounted in the log. This is what gives you the "ramp up" in RPM for the cold start cycle.

Now take it for a drive. I noticed slightly less boost lag in my car, but mostly you just have more room for a pod filter now.

Good Luck!
Any feedback on differences you noticed are welcome, same with any improvements on this procedure. Irrelevant posts will be deleted.

Glossary -
* - LOG - This is the large piece of alloy piping that runs under the throttle body/behind the rocker cover. It has the cold start equipment in it.
--------------------
Trust no-one but yourself.

The beast:
http://forum.n12turbo.com/viewtopic.php?t=3982
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Kimmo
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AFM relocation Kimmo style

Post by Kimmo » Mon Nov 12, 2007 2:21 pm

I figure it's easiest to break it up into three stages; first, you have to make room and strip the AFM lead out of the loom. Second is the actual AFM relocation, and finally the optional step of piffing off the log.

Stage 1
Rather than stuff around relocating the battery to the boot and risking associated complications, not to mention putting things in my boot I can't take out, I saw my battery was small enough to fit into the tray sideways...
Here's what stage 1 involved: battery tray cut flush with the chassis member, battery rotated 90° with slightly longer leads to suit, and also requiring crafty low-profile retention, and the AFM lead stripped out of the loom (you can't really make it out in this shitty phone pic).
Image

And here my nifty battery retention mechanism is revealed in its full glory ; )
(Being so close to the edge of the engine bay, the normal jigger would foul the bonnet... I figured it'd prolly be a good move to cover the positive terminal with a bit of rubber, too)
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Here's what I cut off the battery tray:
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Stage 2
Here are the bits I had to get together first:
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The bit of 3" ally bend cost $45 from the same mob who changed my donk : )
Those bits sprayed black are a couple of 65mm PVC end caps I got from Bunnings; one of em has a 1/2" barb screwed into it - these are to block up the log. The other bit is some 2&3/8" steel with a 1/2" T-piece cut and brazed on with silver solder. Like the other T-piece I had made for the water cooling, I had to get out the butane torch and seal up the holes with electrical solder, but it turned out fine... I almost made it too short, but I think it'll hang in there : )

Here's one of the end caps (the silicone tube I had was a little too large, so I had to put a few turns of tape around the ends of the log and the caps):
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The caps want to pop out when they're in this way; I had to turn em around.

Here's the finished assembly ready for final fitting:
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I didn't require the straight bits on the ally bend, and I figure satin black helps give it that kinda stock look... the end was pretty tricky - the stock elbow/reducer I reused (blocked up the hole with silicone) was slightly too small for the 3" tube required for the pod (I didn't need that chromed bit of plastic that came with the pod, thankfully), so I cut the end off the standard pipe and ground the welds smooth, then with a couple of turns of tape, it was a tight fit inside the tube. Some silicone smeared into each end of the sleeve joint, and plenty of tight turns of duct tape around the outside, and it seems robust enough. The AFM, being the biggest restriction in the inlet, could do with a clean, I thought. There was all this oily gunge built up inside, so I got it apart, cleaned it up, chipped all the old glue off and put it back together with silicone. It'd have to flow slightly better now, I reckon.

Ta-daa!
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Just like a bought one : )
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The overflow bottle holds both the battery and the elbow securely in place.
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There's about an 8mm gap between the fitting I made and the turbo, allowing the hose to flex when the engine moves.
Image

After a couple of days, I'm blown away by how much better it is now... it's got heaps more bottom end torque; it no longer threatens to stall every time I start moving. The pneumatic spring between the AFM and the throttle is banished, meaning it idles more steadily and it's possible to back off in second gear and not have to put the clutch in to avoid an ugly scene... and the noise! At moderate throttle openings there's not much difference, but when I tramp it, it roars... : D
And it comes on boost a fair bit earlier too, which makes me very happy indeed.

I can't believe I took two years to get around to doing this; I should have done as soon as I got my rego...
This has to be the single best mod you can do to these cars by far.


...Oh yeah, I just realised you could probably just drill and tap a hole in the AFM's outlet for the barb fitting; there'd be just enough room, I reckon...
That would be neater (except for the bit poking into the flow, where it counts - I guess you could clean it up with a dremel) and easier. And if you're having a hard time find a bit of pipe to put in the elbow, you could just turn the stock pipe (the surplus one that goes between the elbow and the log) around and cut it about where it bends down. With a bit of silicone hose and sealant and some tape, you could make a nice joint onto a pod filter.
So you could conceivably do this mod for little more than $50, depending on how much you pay for a filter.

Stage 3
First, I made a throttle cable bracket out of a bit of extruded aluminium I knew would come in handy one day...
Image

BTW, I didn't have a tap to put that thread through the bracket, so I made one with a spare screw ; )
Image

Dremels kick arse. The Ozito one I use was $42 from Bunnings.
Image

Then I went the hack on my spare log. The other car is so damn handy; I could take my time here.
Image

Did the home-made tap trick again to get this bit through some more ally plate.
Image

Here's what's left of the log after I bent up some plate and stuck it together with silicone. Turned out it needed a couple of rivets to secure the barb.
Image

Can you see it? Where's Wally? : p
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I pinched the other curved hose from the spare car. A zip tie stops it from bouncing around.
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Room for my blow-off valve now.
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Mmm, tidy :D
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And for the sake of any noobs, the third element of the log removal is the two bits of chunky plate you see bolted to the inlet manifold to block off the water gallery.

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