HOW TO: A'PEXi SAFC II, X-Trail QR25DE - Page 3

**ValBoo** · Mar 30th, 2006, 06:27 AM

Quote:

Originally Posted by Terranismo

..... 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.

Terranismo · Mar 30th, 2006, 01:25 PM

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).

**ValBoo** · Mar 30th, 2006, 05:59 PM

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

Terranismo · Mar 30th, 2006, 08:25 PM

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

Terranismo · Apr 10th, 2006, 08:57 PM

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%

thetimster · May 5th, 2006, 12:41 PM

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.

**ValBoo** · May 6th, 2006, 09:29 AM

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)

LEONGSTER · Apr 15th, 2007, 08:16 AM

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!

**ValBoo** · Apr 16th, 2007, 06:05 AM

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.

LEONGSTER · Apr 16th, 2007, 08:33 AM

Thanks, Marc. This is useful info.

Terranismo · Apr 29th, 2007, 03:55 AM

Quote:

Originally Posted by ValBoo

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.

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%.

xtrail898 · May 15th, 2007, 12:34 PM

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

**ValBoo** · May 17th, 2007, 03:47 PM

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.

xtrail898 · May 18th, 2007, 07:00 AM

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.

**ValBoo** · Jun 2nd, 2007, 09:46 AM

Quote:

Originally Posted by ValBoo

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.