Hello,
I just ordered my VAFC-II today (finally!!), and had a couple questions. Here's Puppetmaster's wiring diagram:


Why would I want to wire the purple wire to the knock sensor wire? Is there any benefit to this, and if so what? I read somewhere that someone had a problem with their VAFC and when they removed the knock sensor wire, all was well... also, just to be sure, is the following all that I need to know to get tuning my AFR?:
Settings: 1in-1out or 4in-4out, Northeast Arrow, Vtec-1.... and then throttle points 40% and 90%...
(if I use these throttle settings, I just dyno tune at ~60-70% throttle for the narrow map AF corrections, right? And then again at WOT for the wide map?)

The rest is pretty straightforward to me... (like the hvt -> lvt settings at 4200 and vice versa at 4100)... but should I tune below 3000rpm? I've read so many differing opinions...
Thanks for any help guys and especially for your patience with my tuning noobness... I've read all there is to read on here about it and I'm still a bit confused.

 

No use hooking up that KS wire.

 

As afar as tuning below 3k, useless depending on your set-up (larger MAF, no breather from the VC connected & larger MAF = lean).

But it seems as if you wont have those problems.

Got WB?

And on KS wire.

In outs should be 1/1 or 2/2, as long as they're the same.

Not sure why you would dyno tune 60-70% throttle. That would be hard to maintain without additional electronics.

 

Dunno how stupid of a question this is but, does that chart apply to all VAFCs? I and II?

 

Ok, so just tune WOT?? Why do you set high and low throttle points then? You might as well not have the narrow 40%-90% then right? I'm so confused about that... If you can explain it that'd be awesome!
And no, I don't have a WB. I plan on just dyno tuning and maybe getting a WB next year.

 

With stock, working O2 sensors and a stock maf, there is no need to tune for partial throttle at all.

 

Oh, ok. So how do I go through the settings to just tune 24 points at WOT? And how do I set the throttle points? Like the points that are usually set to 40% and 90%. What do I do to just tune the 24 afr points at WOT?

 

Oh, and another thing. I am a Mac guy, and don't really have access to a PC laptop for datalogging from a WB. So would it be ok to self-tune by getting an LC-1 wideband, pointing a videocamera at it and the RPMs on my VAFC simultaneously and making a rpm vs. afr graph in excel? Would this be accurate enough? It might be a bit of a pain, but it'd save me some money and be way more convenient cause I have a Mac.

 

i thought somebody found out that VAFC was 1in 4out??? or our OP doesnt have a larger MAF?

 

Yeeaah, I don't have a bigger MAF..... Yet. But hey hustle, d'you have any answers to my ?'s in posts 7 & 8?

 

oh jeez man... lemme go look at mines... i believe it was 49 50... better yet lemme call datdude

 

Like 49narrow 50wide?? And then the car's ECU will only let it correct at WOT? Is that how it works?

 

yep 49narrow 50wide its just basically when the vafc switch from the 12pt tune on low throttle to the 12pt tune on high... we found that 49 and 50 worked best

 

I thought you controlled that by setting the Hvt -> Lvt and Lvt -> Hvt at like, for example 4700rpm and 4600rpm respectively if you're only tuning 3000 and up? I'm so bloody confused...

 

so this is how it acts... the vafc has 12 settings for the lvt and 12 for the hvt... 24 total... if you set the lvt to 49 then 49% throttle or lower the car will be using the lvt corrections once you go 50% throttle or higher it will use the hvt corrections... its the percentage in throttle not rpm's... "throttle" points... not rpm, now within low throttle you have 12 different intervals of rpm that you can adjust fuel

 

But I thought the whole point of getting a VAFC over a SAFC was so you had 24 WOT tuning points. Essential1 just posted and said its pointless to tune partial throttle when you have stock MAF like I do... So what's the difference between setting the throttle points (49 and 50%) and setting the Hvt -> Lvt and Lvt -> Hvt changeover points?

 

it is 24 points... lets say safc divides the 6500 into 12 points the vafc does it in 24 points of adjustmens, just divides the 24 with a hvt and lvt... remember als, the vafc was designed for cars with vtec that pobebly revs to 9K so it gave a little bit more in depth tuning, which is cool for us too but it still is 24 tuning points not 24 points each, that would be 48

 

I'm guessing you've read this?

http://forums.maxima.org/all-motor/3...-template.html

 

Yeah, I got it... but here's the confusion: I thought you were tuning 24 points at WOT? Why would I want to tune the non-WOT (closed loop) functioning of my car? I thought the engine wouldn't allow this, or didn't need it? I thought it was only tuneable after ~3000rpm, when the ECU goes into open loop? And how to you correct AFR at only partial throttle?

Can someone walk me through the setting as to how to tune between about 3000 and 6500 rpms with as many tuning points as possible... I'm confused about Narrow and Wide throttle percentages.

Also, if you set Lvt -> Hvt at around 4700, and Hvt -> Lvt around 4600, and then tune the 12 points for each, how do you get each (Lvt and Hvt) to correct at WOT? I don't want to tune my 12 points for Lvt between 3000 and 4700 rpm, and not have them correcting at WOT.... I have a feeling I'm missing something simple here... but I just don't get it! I don't understand the difference between Lvt/Hvt and the Wide/Narrow Throttle points. I don't know if anyone really understands why I'm confused, but if you can help, that'd be awesome.


Yeah, I've read and re-read this... I'm still confused

 

Ah, wait! Maybe I understand! I re-read the SR20DENs thread, and he says that the VAFCII essentially has a 24x2 map. So that means the Hvt and Lvt have nothing to do with Narrow and Wide throttle points, right??! So you can tune your WIDE throttle (90% and above) with 24 points, split up between Lvt and Hvt and you just have to set the changeover points. Does this sound right???

SR20DENs write-up just doesn't mention Wide and Narr throttle percentages... I've heard 40%/90% is good, I've heard 49%/50% is good, but was under the impression that our cars won't respond to a VAFCII trying to correct anything but WOT fuel trims... is this right? if yes, I might as well just set it to 49%/50% and only tune the 24 points of the WIDE throttle map, right???

See look. The screen looks like this pic:
So do you just stay at "WIDE" the whole time and tune 12pts for Lvt and 12pts for Hvt? Does it work that way?

 

Ah! Yes!! Comprehension at last! It's like I thought. You can do 24pts at the WIDE throttle setting by simply doing Lvt and Hvt settings. It seems lots of people think Lvt means partial throttle and Hvt means WOT. So that is incorrect I guess. So I just need to tune on the WIDE setting.