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



## ValBoo (May 19, 2003)

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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## SCHESBH (May 25, 2004)

*Marc...*

Can you please answer one question for me... and I am laughing while I am saying this... is your X-Trail not leased...? What does the dealer say to all your umm...mods... LOL

Stephen


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## thetimster (May 6, 2005)

What can I say ValBoo!?!?! Thanks a bunch!!

I've had my S-AFCII here with me for a few weeks but haven't gotten around to installing it since my headers has not arrived yet. But now that you've posted a very detailed report, I just had to open the box and look at the manual I got.

A few questions come up immediately. I'm not sure if they are reasonable ones. But I'll ask them nonetheless...

1.) Why is your diagram different from this?



The manual that came with my unit listed this for the X-trail... BUT!!... it is listed as for the QR20DE engine... there is no reference for the QR25DE. Where did you get your diagram from?

I have to assume that since there is no significant change in the QR25DE engine that I've read about, our ECMs ('03 to '05) would be fairly similar. I haven't opened my glove box to actually see if my ECM is the same as your diagram. But if I see a harness similar to yours (2 pieces instead of one), then I'd be sure what my manual is referring to is wrong.

2.) My manual also refers to hot flap wiring versus Karman? The meanings to these are lost on me. How did you know we aren't Karman?

3.) Did you leave the ECU in place while working on the wires? I'd think that'd be the safer/recommended and easier way to go.

4.) My installation manual says to "allow a space of 1 cm of more between the connecting point of the black wire and the connecting pint of the brown wire", not LESS than 1 cm. ???

Other than these questions, your post has already been a big help to me. Now I actually think I can install this myself then bring the X to be dynoed somewhere.

And oh... my X doesn't have that little compartment to place the control panel in. I'll have to look for a better place in my X.

Thanks a bunch for the effort you put in. The pics are nice and the descriptions detailed!

:thumbup: :thumbup: :thumbup: :thumbup:


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## ValBoo (May 19, 2003)

*Q & A*

Hi Tim,

I'll try to answer the best I can:

1) Connection Diagram:
There are 2 separate ECM connectors: The layout more closely resembles SAFC manual, picture N10-c as below:

(You know what? I just noticed I had posted the wrong one on my page ...Sorry)


The corresponding layout can be found in the car's electronic service manual; I doubt very much that yours would be different but you will see immediately when you look at your connectors.

2) MAF sensor type:
There are various methods to measure air flow and three main Air Flow Sensor types: Hot Wire type, Flap type, and Karman type.
The sensor type used on the QR25DE is a "Hot Wire" type. It can be seen by looking at the sensor and also it is described in the service manual.

But I found this link if you are interested in reading about each type of MAF:
http://www.autoshop101.com/forms/h34.pdf 

3) The ECM itself does not need to be taken out. Just unplugging the connector one at a time is enough.

4) Correct. I guess my writing was confusing; I wrote: "no less than 1 cm" meaning you must have more than 1 cm between each ground connection taps. (there is not much room up on that connector wire: I managed to get 2 cm between the wires) 


Keep reading that manual, it can only make things easier if you are familiar with it 

Good luck, & let me know when you decide to dive in.


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## ValBoo (May 19, 2003)

Hi Stephen,

Well since you ask: although I have an "F" plate, the car is on a 3 year "purchase" plan. So there is no problem here.

As for the dealer, they have not asked me any questions or made any comments (or maybe not directly to me, why? have made comments to you?  )

Later
Marc.



SCHESBH said:


> Can you please answer one question for me... and I am laughing while I am saying this... is your X-Trail not leased...? What does the dealer say to all your umm...mods... LOL
> 
> Stephen


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## SCHESBH (May 25, 2004)

*Just curious*

Not to me.. but I can't wait until (not that I wish it) LOL they say something.... heheheh


Stephen




ValBoo said:


> Hi Stephen,
> 
> Well since you ask: although I have an "F" plate, the car is on a 3 year "purchase" plan. So there is no problem here.
> 
> ...


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## thetimster (May 6, 2005)

Hi ValBoo,

Thanks for the answers. Now its more clear. And yes, now that I read your post again, you DID say "no less than 1 cm". My bad.

I'm thinking I can probably do the hardwire connections even without my headers yet. It will just sit there until the headers arrive. As long as it isn't turned on, it shouldn't affect the car, right?

Reading your post is getting me excited. I'm already thinking I might dive in this weekend. Will let you know. 



ValBoo said:


> Hi Tim,
> 
> I'll try to answer the best I can:
> 
> ...


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## thetimster (May 6, 2005)

*More questions than answers*

I've been going through the manuals like you suggested. I think installation is going to be infinitely easier than tweaking it. It measures quite a number of things and allows for so many combinations! This is great in a way... but also daunting on the other. Can you please post what settings you eventually settled with? I don't know how far down my headers are. (Hotshots is 3 weeks backordered and there doesn't seem to be any 4-1 headers now. Now actually at possibly getting Hotbits from Singapore.) But getting an idea of your settings might eventually help me with mine.

Thanks!


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## ValBoo (May 19, 2003)

Hi Tim,

Just as you are, I am also amazed at the amount of stuff that little unit can do (measure)...

You can bet that after tuning I will post as much info as I can.

One set back though, My Tech cannot do my tuning tomorrow... It will have to wait til Monday   .


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## thetimster (May 6, 2005)

Bummer!!    

Will wait for your post/update.


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## ValBoo (May 19, 2003)

*UPDATE !!!*

My installation was completed a couple of weeks ago and so was my tuning.

About that RPM signal connection to terminal 103 which has no wire: 
My Tech informed me that there is another way of getting an RPM signal from one of the "coil pack" wires on terminal 80 or 81 or 61 or 62 (pick any ONE of them; lower left side ECU connector). And since your pulse/RPM signal is collected from one coil only, you simply have to select 1 cylinder in your initial SAFC settings and this will give an accurate RPM information.



My tech. performed the tuning "live" using a wide band O2 sensor and his laptop to record the air fuel ratio throughout the RPM and at pretty much full throttle. Just like the 02 & 03 SpecV QR25DE equipped, it was found that my engine was running very "rich" (11 to 11.5) and that there was lots of room for improvements.

So here are the correction settings done at Hi-Throttle:

Ne01= 1000 rpm; corr: n/a
Ne02= 2000 rpm; corr: n/a
Ne03= 2400 rpm; corr: -15%
Ne04= 2800 rpm; corr: -15%
Ne05= 3200 rpm; corr: -15%
Ne06= 3600 rpm; corr: -16%
Ne07= 4000 rpm; corr: -18%
Ne08= 4400 rpm; corr: -19%
Ne09= 4800 rpm; corr: -19%
Ne10= 5200 rpm; corr: -19%
Ne11= 5600 rpm; corr: -19%
Ne12= 6000 rpm; corr: -19%

Lo throttle= 10%
Hi throttle= 50%


I have been driving my car for just over a week with the correction settings and I must say that there is a marked improvement (feels like the same marked difference as adding an exhaust header, say 10 to 15 HP)

Unfortunately, I have not dynoed my car and must rely on my very own "but-dyno".

My thanks to:
Robin Almasi (aka: S14 Drift!)
of Almasi Tuning, Montreal, QC, Canada.
(514) 567-0617 [email protected]


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## thetimster (May 6, 2005)

I'm glad this became a sticky. This is a stickier install than moving the knock sensor. 

Now with those settings you typed out... are those the ONLY settings you entered in the unit. Aren't there any other settings to set in addition to selecting 1 on the number of cylinders? Did you eventually move the wires to the other locations or did you keep it at terminal 103?

What is your final measured air to fuel ratio after adjusting the unit?

I haven't gotten around to working the unit yet. Just got a lead on the headers and even a downpipe. So now I'm thinking I'll wait until all are in. I hope to eventually add my experience to this thread.


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## ViperZ (Feb 9, 2005)

Nicely done Marc!

Your XTy is becoming one heck of a "Tuner" truck :thumbup: I would love to take it for a test drive just to see how it feels.


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## jwlsin (Feb 15, 2006)

hello valbo. im a newbie here. i just installed my apexi afc2 on my xtrail too.

regarding the setting on the fuel map. what were the results?

my engine is qr25de.

thanks


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## ValBoo (May 19, 2003)

Not sure what you mean about results...
End result is better air-fuel ratio (less fuel in my case) and increased HP.

If you mean the actual fuel map corrections... these are posted above in post #11.

Don't take my corrections as gold, because it really depends on the car, year, and country of origin. You *must* have you car properly tuned (by shop or someone who really knows what he is doing) using a wide band oxygen sensor to then be able to apply the best corrections for your particular engine.


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## Terranismo (Aug 31, 2004)

Marc, I just ordered my AFC today, and hope to have it in a week. I'm still awaiting shipment of other things (pulley, spacers, cams), so I'll have it dyno tuned in March. If anyone wants I can also post up a video once I get it done.


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## jwlsin (Feb 15, 2006)

thanks valbo. iwill do that.


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## ValBoo (May 19, 2003)

Terranismo said:


> Marc, I just ordered my AFC today,....


Good stuff! (mind you I thought you had looked into SAFC before...)

To tell you the truth it is kind of intimidating once you get the covers off the ECU connectors... at least it was for me. Take your time, don't "snip" the wrong wire, he he he 

Did you have en evaluation of your air fuel ratio as it is now?
at least that would give you an idea how much the SAFC could improve things for you (unless you are getting the SAFC for future boost upgrades )

Do post your Vids when available ... its always nice to see other X-trails.


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## Terranismo (Aug 31, 2004)

I don't know the ratio right now, but I can tell you that it is running gasoline stinking rich. I'm having it installed since I'll be putting it very, very away from the ECU connector. I'll surprise you once I get it installed and post some pics.

BTW No boost for now, only nitrous :thumbup:


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## aussietrail (Sep 24, 2004)

Hi Marc,

Now I got this mod drilled in my head, I want to find-out more information about it if I may 

I can get this unit here in Australia and I can have it installed, dyno-tuned and all that (the fitting and dyno tuning is gonna cost me double the price of the actual apex'i  )

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.


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## Terranismo (Aug 31, 2004)

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.


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## aussietrail (Sep 24, 2004)

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


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## Terranismo (Aug 31, 2004)

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.


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## ValBoo (May 19, 2003)

aussietrail said:


> Hi Marc,
> 
> ..................
> 
> ...


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)


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## aussietrail (Sep 24, 2004)

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?


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## Terranismo (Aug 31, 2004)

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.


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## aussietrail (Sep 24, 2004)

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!


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## ValBoo (May 19, 2003)

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!


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## ValBoo (May 19, 2003)

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


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## Terranismo (Aug 31, 2004)

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.


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## ValBoo (May 19, 2003)

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.


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## Terranismo (Aug 31, 2004)

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).


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## ValBoo (May 19, 2003)

I'm still not sure what pressure points are ... but I'll search. just give me a few days...


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## Terranismo (Aug 31, 2004)

Check your AFC manual (the one that looks like a poster).


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## Terranismo (Aug 31, 2004)

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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## thetimster (May 6, 2005)

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.


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## ValBoo (May 19, 2003)

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)


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## LEONGSTER (Apr 9, 2006)

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!


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## ValBoo (May 19, 2003)

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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## LEONGSTER (Apr 9, 2006)

Thanks, Marc. This is useful info.


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## Terranismo (Aug 31, 2004)

ValBoo said:


> Here's how A'PEXi SAFC works:
> You can have it set with two different metering maps:
> 
> example:
> ...



Marc, from what I've read on the Spec-V forums, we should just set the high map since the QR just reads on closed loops when not under aceleration or when the accelerator is not fully depressed. I just set the high map and have it kicking in at 35%.


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## xtrail898 (Aug 31, 2006)

Thanks Valboo. hope we can share more experience. did u dyno ur xttail after install safc II ?how many hp add?tnx.


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## ValBoo (May 19, 2003)

Hi Wilson,
No dyno before or after any of my mods unfortunately.
But depending how bad (rich) your air fuel map is you may expect 6 to 7% improvement in power with a good map adjsutment.


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## xtrail898 (Aug 31, 2006)

Hi Valboo,
Glad to hear ur feed back.can u teach me how to tune my safc2 ? bec i just installed it 2wks ago,but until now stil not tune .thanks.


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## ValBoo (May 19, 2003)

ValBoo said:


> Hi Wilson,
> No dyno before or after any of my mods unfortunately.
> But depending how bad (rich) your air fuel map is you may expect 6 to 7% improvement in power with a good map adjsutment.



Hi Wilson,

Since you asked about this...
I was browsing on an another forum and found this dyno graph relating to the addition & tuning with an SAFC...this is really good info:



This is based on a QR25DE engine out of Spec V but the air fuel ratio numbers look alot like mine were:
You can see that prior to tuning this graph shows a rich air fuel mixture at 11.5 to 12.0.
After tuning it is leaner at 13 to 13.5.

The horsepower numbers are represented at the wheels and show a peak increase from around 150 to 165. This translates to an increase of 10%... a little more than I mentioned in my earlier post .
Hope this helps.


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## xtrail898 (Aug 31, 2006)

Hi Valboo,
Thanks so much of the picture n teach.hope i can tune it like the picture. hehehe


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## aussietrail (Sep 24, 2004)

Marc, I am now looking at getting the Apexi for my exy (that sounded good LOL) to correct the running rich problem I am having, but when I started to look for to aqcuire one I noticed that there is a new release product that was released after the Apexi SAFC II, called the APEXI AFC NEO which seems to do everything the SAFCII did and offer more.

Do you know anything about it and if it can be hooked-up to the exy in the same way the SAFCII?

Also, I have been getting conflicting recommendations about the use of the Apexi due to the fact that it doesn't offer timing advance capabilities which other similar devices (like eManage and others) can offer.

Is timing advance capability really needed, considering that the TA can be done as a one off setting or do I need to look to have the TA value adjusted for all RPM ranges?


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## ValBoo (May 19, 2003)

Jalal,

I have looked over the AFC NEO... looks good and wiring seems to be the same.
see link for manual and wiring (PDF):
APEXi - Super AFC NEO - Manuals and Documentation - Nengun Performance


I cannot answer your question about the need to control timing advance: I just don't know enough on it (yet).


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## aussietrail (Sep 24, 2004)

Thanks Marc. I have decided to go with the Unichip that controls both timing and fuel:air ratios. Will update you guys when it is all fitted and dyno tuned.


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## Revhead Kev (Apr 1, 2007)

Marc,
The documentation only shows Nissan Xtrail QR20DE.
How different would the ECU be for the QR25DE we have ?


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