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HOW TO: A'PEXi SAFC II, X-Trail QR25DE

22750 Views 49 Replies 10 Participants Last post by  Revhead Kev
9
Ok it is finally here:
Here is my humble "how to" for the installation of A'PEXi SAFC II on X-Trail 2005 QR25DE engine (Canadian Edition):

** This write-up does not cover the initial set up configuration and tuning of the SAFC II. This should be done by a knowledgable tech.
** Also take note that once your SAFC is installed and powered you should immediately do initial set-up before starting the engine.

** Warning:
- Not for the faint at heart.
- Knowledgeable and at ease with wiring & soldering is a must.
- Not responsible for "screw ups".

I can't say it enough: Read, Re-Read, and PLEASE Read again ALL documents supplied by A'PEXi with the unit.

Find a suitable location for mounting the unit.
I located mine in the hidden double door compartment below the climate controls. (see below)


Take off some side panelling to find a suitable route for the cable.

Access the ECM location by:
- removing the "lower panel" (part 27 in picture) snaps in only
- removing the "glove box" (part 31 in picture) by removing two holding pins (part 32 in picture)
- removing the "glove box cover" (part 36 in picture) held in place by a quantity of 6 screws (part 3 in picture)
(While taking this last part be careful not to pull apart the air bag connector)




So far these steps are the same as what is needed to access the "cabin air filter" (models equipped).

You should now be able to see the ECM as per below:


WARNING: Before disconnecting any ECM harness connector: YOU MUST Disconnect the batterie negative terminal.
(unfortunately this will screw up radio settings and clock :( )

Disconnect harness connectors as per pic below and carefully remove the protector covering the connectors.


Also carefully pull away some the black plastic wire covering; you should now be able to see clearly the pin connector and each wire.



Start identifying each wire color and confirm the terminal point number:

Terminal----car ECM--------------sensor------------------A'PEXi SAFC II
number----wire color---------------------------------------wire color

# 15---(wire color white)-------Knock sensor---------------color purple
# 50---(wire color white)-----Throttle position--------------color grey
# 51---(wire color orange)---Mass Air Flow sensor--------color white & color yellow

# 116--(wire color black)----------Ground------------color brown & color black
# 120--(wire color grey)-------Power Supply----------------color red
# 103--(---no wire----)--------Tach RPM-------------------color green



All SAFC wires tap onto ECM wires except for the MAF sensor;
MAF sensor wire is to be cut:
SAFC's yellow wire connects to ECM side of #51 orange wire
SAFC's white wire connects to car's MAF sensor side of orange wire

In the case of the car ECM RPM signal:
Some model years (in this case 2005) do not have a wire attached to the terminal # 103;
you therefore have to get inventive on how to insert a wire into the terminal # 103 and get a good connection. Some report heating wire end covered with solder and inserting it into the terminal socket, but I would prefer some other method; I have not figured that one out yet but as soon as I do I will write a follow up.
In the case of the SAFC ground wire: there are two wires (brown & black) that need to be connected to the same car ECM ground wire with only a small space between them (no less than 1 cm). Also note that the SAFC brown wire should be the one closer to the ECM side.

- The above wire color codes correspond to my 2005 X-trail with QR25DE Canadian Edition.
- Color codes for your particular car should be doubled check in your applicable service manual since they may not necessarily match.

Once all connections are done, soldered and secured, tidy up the harness, put back the insulation, button the harness back to the ECM and close up the area in the reverse order.

(I will be seeing my tuner/technician/chemist this coming thursday for proper tuning, and will report back on the improvements)

If you are interested in accessing my SAFC II on my page, here is the direct link:
"SAFC II"

There you go, I'm done. I hope this helps and is not too confusing...
Comments welcomed.
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Jalal, I'm not Marc but I've been running my AFC II for two weeks now. I noticed a drop in gas consumption and also a reduction in unburnt gas fumes from the exhaust. My exhaust also does not burble or backfires like before. The increase in power (when tuned), can be really felt, and the added guages help also to monitor engine statistics.

Tomorrow I'm having my truck dyno tuned so I hope I can post some pics and vids.

BTW where are the rest of the X-Trail people? This forum seems dead lately.
Thanks Terranismo,

How much of a drop in fuel consumption are we talking about here?

What is the fuel:air ratio setting you have set the apex'i to?

Nah, this forum is going OK, spring is just starting there, so they must be all out swapping winter tyres to summer ones LOL :)
I set it to the same high throttle and rpms setup Marc posted. I haven't been able to measure the consumption rate on a full tank yet.
aussietrail said:
Hi Marc,

..................

I need to know what was your fuel consumption like before this mod and after? since you've been running with it for quite a while.

What I'm trying to establish, is the benefits to fuel consumption should I go down this path which will in turn help me recover some of the money am gonna spend on this mod (which looks like over $1000AUS!!!)

Power and performance increase are secondary targets for me doing this mod. My exy is running rich 11:1 at the moment and I want/need to fix this problem and if this is gonna give me more power, then that'll be a bonus :)

Look forward to your reply.
Hi Jalal,

Sorry for the late response, I wanted to reply but Terranismo kept "cutting me off" ... ha ha ha :)

Don't do it for the fuel saving, you may not see that much of a difference.
Just as mine, your stock exy is running rich, but that is not necessarily "a problem"...

The way mine is set up, the corrected fuel map only takes effect in high throttle position; ie when throttle is open more than 50%; ie when you need the extra power. (If you really notice when you daily drive, your throttle is rarely open more than 50% unless you are taking off from a light or when needing to overtake on the highway)

:)
Thanks for the advice Marc.

So, you're saying that the fuel saving is not that significant to justify spending that sort of money of this mod?

I know that Nissan has set the stock exy to run rich to minimize the chances of warranty claims, but what are the risks of running lean? :)

Since the extractors and exhaust system upgrade I stay more often on higher revs :) That is at the lights and on the highway, but majority of my driving is between 2,500-3,500RPM

The above price I quoted includes a dyno tune, has yours been dynoed at all? If yes, what was the confirmed power gain?
The risk of running too lean is detonation. The ideal air/fuel ratio on our engines should be in the 13.5 range. I just came back from having my truck dyno tuned (172whp and 169lbs-ft of torque), and have my settings if anyone is interested.
Wow Terranimso, that is really impressive!!

Is that at the wheels reading after the nitro experiment?

Do you have the dyno charts for us to look at?

Excellent stuff!
Terranismo said:
The risk of running too lean is detonation. The ideal air/fuel ratio on our engines should be in the 13.5 range. I just came back from having my truck dyno tuned (172whp and 169lbs-ft of torque), and have my settings if anyone is interested.

But also ... the better tuned air/fuel (ie close to 13.0 - 13.5) will make for better burn and higher burn temperature which may affect the pre-cat and lead to the known problems with that.... At least for those who still have stock header.

-- Very good wheel numbers there ;)

And yes, yes, yes please list your safc settings it will be nice to compare!
aussietrail said:
Thanks for the advice Marc.

So, you're saying that the fuel saving is not that significant to justify spending that sort of money of this mod?
Correct, (at least that is my opinion)


aussietrail said:
Since the extractors and exhaust system upgrade I stay more often on higher revs :) That is at the lights and on the highway, but majority of my driving is between 2,500-3,500RPM?
But, keep in mind that "Throttle Opening" and "Revs" are two different things and don't necessarily match each other (I'll let you think about that one for a whyle ;))


aussietrail said:
The above price I quoted includes a dyno tune, has yours been dynoed at all? If yes, what was the confirmed power gain?
No, sorry, unfortunately no dyno was done on mine at all :(
I was never able to reach a 13.0 a/f ratio. The X just kept on at a 12.0-12.4 range. The graphs were linear (made over 8 pulls) with a spike just when the rev limiter hits at 6400rpm. Marc, did you tune using the AFC pressure points?

Jalal, those numbers are fully N/A, the bottle is not yet connected. I'm planning on investigating a bit more about the AFC and going back to the dyno when the kit is in place. I know I can still pump out at least 8+whp from my current N/A setup.
Terranismo said:
..... Marc, did you tune using the AFC pressure points?
I'm not sure I understand afc pressure points?
When mine was tuned, I had the "tuner guru" sitting beside me in the car with his lap top. A wide band O2 sensor was connected to the header, and with each drive, full throttle in second gear, he was able to get a live graph of the a/f ratio. The SAFC was adjusted with each drive until the a/f ratio was optimal.
Marc, the AFC has the option of being tuned by pressure points, and also to vary the knock sensor, and air sensor (MAP or MAF).
I'm still not sure what pressure points are ... but I'll search. just give me a few days...
Check your AFC manual (the one that looks like a poster).
Forgot to post my settings. Here they are:

Lo 30% Hi 70%

3400 0%
3800 -2%
4200 -3%
4400 -5%
4600 -8%
4800 -15%
5200 -16%
5600 -18%
6000 -18%
6200 -18%
6400 - 15%
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Hi guys. Been a while since I've been here. It is GREAT to see all of you here... especially Terranismo.

I finally had my SAFC installed as well. Some of you might remember I had it purchased and just sitting around waiting for me to get the courage to do it. Well I finally had it professionally installed and like Valboo, had a tuner with a laptop and online O2 measurements made by slaving it to an O2 sensor.

The added boost is amazing! And like Valboo, I did not notice an increase in gas consumption but actually better mileage. All in all a 10 to 15% increase in mileage.

Power is awesome and is felt across nearly the whole RPM range. I'm sorry, I didn't copy down my settings. I was too busy keeping my eye on the road while I was redlining the X. But now that it is done, I agree 100% with Valboo. The boost is almost like when the CAI and headers/exhaust went in. Only this is ON TOP of the CAI and exhaust boost.
Nice to see you again Tim!
Good stuff about your SAFC install ! Glad you like it.
About your settings: you can view them on your unit and write them down so that we could compare... :)
(... be careful not to change them as you view them)
I'm doing some research on AFCs at the moment and maybe the chaps here that have intsalled one can help?

1) Does the A'PEXI SAFC II function when the engine is in Closed Loop. Or only when it's in Open Loop (Say, with WOT).

Any feedback would be appreciated!
Here's how A'PEXi SAFC works:
You can have it set with two different metering maps:

example:
Map 1 which is applied at 35% wot or below
Map 2 which is applied at 75% wot or above

When you are in-between 35% and 75% wot the unit will proportionally interpolate settings between Map 1 and Map 2.

Hope this helps.
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