vafc 2

[hothatch03si]

i just had my vafc 2 installed this weekend and have been messin around wit it ... does anyone else have this in there car and if so wut r u guys settin it . i have dc header,aem cai, greddy evo full catbak

[aRz]

i dont get it, i was having it installed from this place here in ft lauderdale fl, called Dynamic turbo. This place does major work and all are pro's there. well anyway i was having min installed it took from 11 in the morning till 7 at night and i havnt even changes the settings on it ! for some reason as we lowered vtec to about 4.5 we test drove the car and the controller wouldnt let me rev past 4.(what we set vtec at..) any ideas to what could be wrong ??? thanx alot aarie.
im running the controller with a dc sport short ram hp header and 2.25 cat/cut exhaust

[danoonez]

You're gonna catch heat for saying that you lowered your Vtec changeover to 4.5k rpm. Just be ready for it.:D

[DC5RK20A]

Originally posted by aRz
i dont get it, i was having it installed from this place here in ft lauderdale fl, called Dynamic turbo. This place does major work and all are pro's there. well anyway i was having min installed it took from 11 in the morning till 7 at night and i havnt even changes the settings on it ! for some reason as we lowered vtec to about 4.5 we test drove the car and the controller wouldnt let me rev past 4.(what we set vtec at..) any ideas to what could be wrong ??? thanx alot aarie.
im running the controller with a dc sport short ram hp header and 2.25 cat/cut exhaust

aRz,

I know that the VTEC mechanism is different between the K20A3 and my K20A in my ITR, but when I first installed mine, one of the wires that controls the VTEC had come loose, didn't even realize it, went driving to test it out, and the car just bogged at the VTEC changeover, wasn't sure what was wrong, I started to play with the fuel settings, thought maybe that was the cause, still wouldn't operate correctly, eventually the check engine light came on and I just went home. It was like 3am in the morning, so I left it for the morning, rechecked all the wiring and noticed that the VTEC wire that goes into the ECU was disconnected. Reconnected it, reset the ECU and since then all has been great. This possibly might be the cause, or recheck all the wiring, make sure your colors are going to where they should be. Wow 8 hours to install! That is a little shocking that it took so long, I had mine in my car in like 1.5 hours. If that is not the cause, I'm not really sure what it may be. Good luck with it.

Chris

[Tenacious G]

the A3 "VTEC" engages at 2200 rpm. so you'll want to recheck your VAFC settings.

[hothatch03si]

about ur vtec controller boggin a 4,000 rpm , wen my friend was tunin it the same thing happend to mine but now its fine and it even increased my redline somehow to 7200

[DavidT]

Your tach is off, 7200 RPMs on the tach is 6800 RPMs in real life. To date, the only company that offers any rev limiter that is higher than stock is Hondata, which bumps it to 7700 RPMs, about 8100 RPMs on the tach.

[aRz]

yo thanx for the reply's ! what i did was reset the cotroller to stock setting's for now till i find out whats wrong. im going outside to check tose wires... thanx for the info, by the way did you guys feel a big difference? im gunna go to SFP so i can tune it on the Dyno over there thanx...

[02NJHondaep3]

our redline is 6800 but fuel cutoff doesnt come in till a little past 7200

[myeverlovinsir]

Originally posted by 02NJHondaep3
our redline is 6800 but fuel cutoff doesnt come in till a little past 7200

Wrong, that's just not true. The stock fuel cutoff is the redline (6800rpm). I don't think you have dynoed your car. That will prove it for you.

[aRz]

why the hell is my vafc 2 giving me so manny problems
its still tuned stock the shop im going to says there going to re'wire it through these sensors..? does that make any sence my boy that works there checked the wiring to the ecu 3 times over and he says everything was placed correct i dunno wtf is wrong w/ my f'ing shit ! .. damn

[aRz]

by the way once i get it tunes on the dyno how much performance am i gunna get out of it. i running it w/ i/h/e hondata manifold gasket.

[Tenacious G]

Originally posted by aRz
! for some reason as we lowered vtec to about 4.5 we test drove the car and the controller wouldnt let me rev past 4.(what we set vtec at..) any ideas to what could be wrong ???

perhaps this is your problem. the K20A3 does not have a VTEC changeover. the fact that you've lowered the VAFC's VTEC engagement to 4K rpm, there is no VTEC lobe for the engine to switch over. i'd be willing to bet money that since the A3's VTEC is non-existent, the ECU simply thinks that's the new redline. try changing your VTEC setting back to 6800 rpm, and just mess with the A/F settings and see what happens.

[DavidT]

Ahh Tenacious that's kinda incorrect. We do have a VTEC mechanism, it opens up the other 4 intake valves at 2200 RPMs. It's not a high duration lobe VTEC but it's still VTEC operation. Raising the VTEC to 4000 RPMs means its running on 12-valves longer than it should be. Setting VTEC at 6800 RPMs means your basically running a 12-valve motor not a 16-valve motor cause that's where our fuel cutoff is. If anything set your VTEC to like 2000 RPMs or something because our VTEC operation is for economy not performance.

BTW, when your ECU goes into limp mode it won't let the motor rev above 4k. You have to adjust everything correctly so it's within readible specs of the ECU for it to work correctly. I'm willing to bet you guys wired something wrong ;)

[Tenacious G]

Originally posted by DavidT
Ahh Tenacious that's kinda incorrect. We do have a VTEC mechanism, it opens up the other 4 intake valves at 2200 RPMs. It's not a high duration lobe VTEC but it's still VTEC operation. Raising the VTEC to 4000 RPMs means its running on 12-valves longer than it should be. Setting VTEC at 6800 RPMs means your basically running a 12-valve motor not a 16-valve motor cause that's where our fuel cutoff is. If anything set your VTEC to like 2000 RPMs or something because our VTEC operation is for economy not performance.

BTW, when your ECU goes into limp mode it won't let the motor rev above 4k. You have to adjust everything correctly so it's within readible specs of the ECU for it to work correctly. I'm willing to bet you guys wired something wrong ;)

David, it depends on how you define VTEC. everyone has come to know and love VTEC as switching from a 16-valve low lift/duration to a 16-valve high lift/duration. the A3 get's diet VTEC ... IMO it's not "true" VTEC.

i know you're correct in your definition of the A3's version of VTEC ... but in aRz's original post, he is under the impression that he lowered his VTEC engagement point, not extended it. that's where i'm confused as to why his ECU has gone into limp mode and why i think his settings are off.

[aRz]

ok so here's an update.

i went back to the shop, they disconnected the vtec wire to the ecu.
everything else is connected correcly, i can set the air fuel ratio now, but im not going to play with anything. im waiting untill saturday to take my car to the dyno to have it tuned. what do you guys think? also isnt it tru the vtec hits at different lobes and it may engage at 2200 rpm but the one you feel would be at a diffrent lobe at higher rpm..?

[myeverlovinsir]

Originally posted by aRz
ok so here's an update.

i went back to the shop, they disconnected the vtec wire to the ecu.
everything else is connected correcly, i can set the air fuel ratio now, but im not going to play with anything. im waiting untill saturday to take my car to the dyno to have it tuned. what do you guys think? also isnt it tru the vtec hits at different lobes and it may engage at 2200 rpm but the one you feel would be at a diffrent lobe at higher rpm..?

What you're feeling at about 4.5k rpm, and you should see it on the dyno, is resonating tq. It a harmonic effect that happens when air starts to flow well (increased velocity) through the head and valve lift on the intake side. Good for about another 5-7wtq in that range, depending on your I/H/E setup. You are on the larger intake lobes @ 2200 rpm. Back in the day there was quite a debate about that little tq hump, I was also fooled by it;)

[aRz]

im running dc sport sri hp headers 2.25' piping cat/cut apex-i muffler

[myeverlovinsir]

The CAI should help you more. The HP header will not show as dramatic a tq hump as the DC sports, reason being is the DC uses a baffle plate at the downpipe connection (4-2-1) that keeps the velocity/tq up better than the HP 4-1 design from my experience. I have seen the HP show a couple more top end horses though. The crush 2.25 is just about perfect, however the axle back shows little or no gains compared to the stock muff, it boils down to what sound effect you like.;)

[danoonez]

Originally posted by myeverlovinsir
What you're feeling at about 4.5k rpm, and you should see it on the dyno, is resonating tq. It a harmonic effect that happens when air starts to flow well (increased velocity) through the head and valve lift on the intake side. Good for about another 5-7wtq in that range, depending on your I/H/E setup. You are on the larger intake lobes @ 2200 rpm. Back in the day there was quite a debate about that little tq hump, I was also fooled by it;)

You are the s***

[DC5RK20A]

Originally posted by aRz
ok so here's an update.

i went back to the shop, they disconnected the vtec wire to the ecu.
everything else is connected correcly, i can set the air fuel ratio now, but im not going to play with anything. im waiting untill saturday to take my car to the dyno to have it tuned. what do you guys think? also isnt it tru the vtec hits at different lobes and it may engage at 2200 rpm but the one you feel would be at a diffrent lobe at higher rpm..?

Damn aRz, I just thought about it. Is the VTC setup correctly. The VTEC mechanism can be set for either type 1, 2, or 3. On the ITR, CTR and Type S it is mechanism type 1. This setting is on the setup portion of the controller. This might be the problem, as from A'pexi it is setup as type 1. Check this setting, your wiring probably isn't the problem.

Chris

[AsH KatCH ME]

I have the vafc 2 also, at first i had my friend wire it for me and i got chck engine light and wouldnt let me go pass 4k rpms, so i took it to the shop and they told me that you arent suppose to connect the VTM wire on cars with i-vtec, well i got my shit dyno tuned, they set the vtec to engage at 4100, it feels right, add me to your buddy list i want to see yor guys settings. my screen name is the same as my ephatch name. i want to see your guys fuel map set up

[PeteSan3]

I just trying to follow the post here. What does limp mode mean exactly, and what would cause the engine to go into "limp mode"?

[PeteSan3]

^^ Nevermind, I read up on it.

[1fastminivan]

Ash Katch Me

When you say your vtec was changed to 4100 how does that feel? Is there a noticable pull or change? Ive heard stories were you can feel the "vtec switch over" like on the old bseries motors with the VAFC.

[Tenacious G]

Originally posted by 1fastminivan
Ash Katch Me

When you say your vtec was changed to 4100 how does that feel? Is there a noticable pull or change? Ive heard stories were you can feel the "vtec switch over" like on the old bseries motors with the VAFC.

LOL ... so what, it would go from really slow to not as slow?

;)

why would you want to hamper the engine's performace by running on 12-valves to 4K rpm?

[AsH KatCH ME]

yeah kicks i hella nice, its like dam ! haha i can take gs-r with intake and exhaust not hella bad, a car lenght at the most

[fsugatorbait]

Originally posted by AsH KatCH ME
yeah kicks i hella nice, its like dam ! haha i can take gs-r with intake and exhaust not hella bad, a car lenght at the most

http://www.imagestation.com/picture/sraid101/p92a8fa81a1159444600b81ecc52f1bfc/f9e1dd69.gif

[aRz]

ok thankyou for all the help, im taking all that info down and driving my car out to the shop tomarow. i dont know about the setting 1 2 or 3 modes. i herd the vafc 2 comes stock from apex-1 in mode 1 and that only works with the ctr itr and type s im checking to see if that is correct, im also going to check out if i connected the "VTM" wire i herd that should be disconected w/ the i-vtec motors.1 more thing, how do you feel about changing vtec to engage at 4100 rpm is that bad for the motor? a fellow ep'r says thats what he has his set to and that he feels that dramatic push the older b-series motors gave out once they hit vtec. well thanx for evrything, aRz

[aRz]

Hahahha thats some funny shit

[AsH KatCH ME]

I havent heard of any problems with the vtec engaging at 4100 rpms. oh and it does kick in hard like b series

[fsugatorbait]

Id have to see a dyno to believe that. That kick you get is probably because your only running on 12 valves up to 4100rpms and when you switch to 16 valves it feels like the b series vtec. Up to 4100 rpms though your engine is running at only 75% power.

[aRz]

can you guys show me a diagram of what your talking about with the VTM wire? do you mean VTC?? In the apex-1 manual it says do not connect the VTM wire so whatever shop connected it their a dumbass's for doing it because they abviously didnt read the manual but thanx for the info

[dobiejoe]

I have the VAFC 2 in my 03 si. I only have the fuel setup to add more gas at HVT (VTC) above 60% throttle and its ok. If I understand the thing right if you adjust the fuel its only fuel and not air. You could run into a rich condition. I agree with one of the last replys, if you move the VTC point to 4000+ rpm then you are only running at 75% power till then. Yes you will get a sudden surge of power when the new four valves open but thats just more air and gas with one more valve each cyl and not the true VTEC that changes duration and length of travel.

One thing I would be VERY carfull of is the fuel map setting for the differance between 2200 (normal VTC) and 4000+, your new one. If you did not change the fuel amounts for the diffrance then you are hurting things. Your putting fuel in at the rate the ECU is programed for thinking its in VTC and will be running a lttle rich for those couple thousand rpms. Not only a little rich but a bad cumbustion cycle for air and fuel swerl affects in the cyl. There is a setting in the VFAC2 for adjusting this and warns you in the manual to do so. You are not just changing the fuel but tricking the compter to add more or less by the way the VFAC tricks the ECU into thinking your lean or rich.

I would leave it at 2200. You cant change it any less the VFAC will only go to 3500 at its lowest and thats it. So just erase the setting and it will revert back to stock VTC engagment points that are from low to high 2200, from high to low 2000.

This is what I have set. Same VTC point and a ramped fuel curve at high throttle settings above 60% and only in VTC mode
3500 +1
4000 +3
4500 +4
5000 +6
5500 +7
6000 +8
6500 +8

This all brings me 15% from rich

AEM CAI, DC headers, strait pipe, Greddy EVO, setup VFAC2, GET RID OF THAT GOD DAMN INTAKE HEATING SYSTEM...

= 169 to the wheels

No I dont know everything but I sure hope that masters and auto engineering pays off. And I'm old. the first honda I started tweeking was when I got my licence at 16 in 1983 when the ramons, heart, pretenders, and the clash were the sh!t...


later

[hothatch03si]

2 questions when u say get rid of that dam intake head sheild wut do u mean and second when u say = 169 hp do u mean u had it dynoed at that or r taken a guess

[dobiejoe]

The intake manafold is heated. Its supplied hot water from the cooling system to aid in emisions by warming up the car faster and allowing the fuel to burn more evenly at higher more stable temps. this, lighter oil, new computer technoligy and better cats make for a cleaner car. and meets the 2006 CARB rules. This has been around for many years in cars but mostly in big rigs and jets.

As we all know cooler air to the intake is denser air and more power. This setup that honda ans many other makers use is good for emmissions but not HP. it can be removed from our intake there are some topics on this forum about it.

As far as my HP goes that was done on a crappy dyno and that was the best result after four pulls. My best gues would be its about 15-20 less then what it said.

I think the K20 has some potental but want to wait a little longer to see how they hold up to all these people putting turbos on them. There are alot of miner apects like intakes and exhast evacuation that I dont like but I think it will change soon with futer aftermarket part.

[fsugatorbait]

I think your the first one so far to actually post your settings from a VAFC, thank you. Did you notice any difference on the butt dyno over stock? What was your baseline HP #'s? Do you think that the VAFC is good for any real gains on the A3 with only boltons?

[dobiejoe]

My car was never dyno'd prior to the VFAC2. So I have nothing to campare it too. But then the setting are in the VFAC there is a very noticable gain in the HP. There is a good amount of kick in the ass when you see the dispaly reach +7%. Its very good. All you need to do is get more air in so that you can put more gas in. Right now thats the most extra fuel I can put in without riching out the car. They make a little electronic supercharger for all cars thats a piece of crap. It only puts out 2.5 PSI and is 100 dollars. It sits just aft of the air filter. I always thought it was a piece of crap. But when I tried my friends in my car that was removed from his truck. According to the readings I got I went from 15% from rich to 35% from rich with it. That ment I could increase my fuel numbers buy 4 each. I did not get it dyno'd But I think it was good for 20Hp. Now using the thing by itself without the VFAC it does nothing but make a cool sound and drain the battery. Its actually very crappy unless you do it right.

[fsugatorbait]

So you definately noticed a gain in HP? thats interesting. Have you noticed any difference in mpg since you've made the adjustments?

EDIT: how are you measuring % from rich?

[Tenacious G]

ok, this is my understanding from dobiejoe's posts.

he dyno'd at 169 whp with I/H/E and VAFC. however, according to bad dyno estimates, he says whp is more along the lines of 149-154 whp. that sounds about right considering members with I/H/E are putting about 145-150 hp to the wheels. meaning he's seeing around a 5 whp increase from the VAFC2.

i'm still convinced that the VAFC is no more helpful than the SAFC since the A3 doesn't have real VTEC ... but the real benefit from both would be in a boosted application.

just my .02

[dobiejoe]

Yes the VFAC would so the same thing as the VFAC2 and be more economical since there are things in the VFAC2 that we can not use.

I use a fuel air meter hooked up dual band to both O2 sensers. It works great but only after the car has warmed up and the O2 sensers are running at there norm engine temp.

I think it is more then 5 Hp for the thing. I think its more like 10-12. But I would need to dyno it to tell.

[Hatch02SI]

Originally posted by dobiejoe
My car was never dyno'd prior to the VFAC2. So I have nothing to campare it too. But then the setting are in the VFAC there is a very noticable gain in the HP. There is a good amount of kick in the ass when you see the dispaly reach +7%. Its very good. All you need to do is get more air in so that you can put more gas in. Right now thats the most extra fuel I can put in without riching out the car. They make a little electronic supercharger for all cars thats a piece of crap. It only puts out 2.5 PSI and is 100 dollars. It sits just aft of the air filter. I always thought it was a piece of crap. But when I tried my friends in my car that was removed from his truck. According to the readings I got I went from 15% from rich to 35% from rich with it. That ment I could increase my fuel numbers buy 4 each. I did not get it dyno'd But I think it was good for 20Hp. Now using the thing by itself without the VFAC it does nothing but make a cool sound and drain the battery. Its actually very crappy unless you do it right.

where do you find these lil' supercharger thingy's... Also when are you gonna dyno with it?

[aRz]

quick ?...

the settings you posted before, did you set both (Narr.Thr) and (Wide.Thr) to the same settings?


OR...


Just Narr.Thr

Just Wide.Thr

or both?

i set both (Wide.thr) and (Narr.Thr) on my vafc 2 last night and didnt feel much of a differnce to the accroding to the seetings you posted. should i have only set one or both?

[02NJHondaep3]

What do you mean our real redline is 6800? So all of our tachometers are off?

[fsugatorbait]

Originally posted by 02NJHondaep3
What do you mean our real redline is 6800? So all of our tachometers are off?

Yeah! :rolleyes:

[dobiejoe]

aRz

I only set the WIDE/HVT to those number I did not set anything else just left them alone. The narrow and wide is for throttle setting.
I have mine set like this

Narrow = 40% throttle or less
Wide = 60% and above

So my correction are only used when i'm in VTC mode with the throttle above 60%. That way nothing changes from stock when I drive like a sane person.

For the questions of reline being 6800. Well YES it is. It has allways been that way. Thas published on the Honda site under engine specs. That does not mean thats when the rev limiter goes off. It goes off a couple hundred above it. As far as your tachs being off, well yes they are very much off and no way near correct. If you tap a tach into the computer, giagnostics port, or have a VFAC you are 100% accurate. Mine is up to 100-200 off most of the time, sometimes more.

[danoonez]

Originally posted by dobiejoe
For the questions of reline being 6800. Well YES it is. It has allways been that way. Thas published on the Honda site under engine specs. That does not mean thats when the rev limiter goes off. It goes off a couple hundred above it.

Yup. I bounced mine off the limiter in first so I could see what it was with my digital Rev/Speed meter. It read 7049 or something like that. The limiter is at 7000, I just hit 7049 cause I was bouncing off of it.

[VIZHUNZ02SI]

ok i've read n read all of the different typs of opinions and experiences. i recently install my vafc 2
and i need setting for every lil thing. only part i did my self was the initial set up. can some one provide me with there settings and what wire or wires that i should or shouldnt connect. someone said vtm , vtc, vtec, its getting confusing.i jus needs fact on
wide thr wide hvt and lvt
narr thr narr hvt and lvt
v/t cont
v/t unmt
v/t pres
th-point
ne-p hvt
ne-p lvt
vtc set

i would greatly apreciate it for those than can supply all of the following above.if you can jus look into your vafc2 n just copy the info so i can see what this black lil box does.

[S2KplusSI]

I just put a VAFC II in my S2000 and with tuning, it gained 10.5 WHP peak and around 20-25 at 6000 RPM. I know this isn't the same as a car with i-VTEC, but I believe if this is done right, it'll be a good investment. Good luck with it.

[VIZHUNZ02SI]

yeah im tryin to avoid going to a perfromance shop here in miami or in ftlauderdale
they seem to ask for sh*t load of money jus for a few minutes of tunning

[cogpdaddy]

i am new i have had my car for about two months so far i have i/e and my question is can you use any vafc or is there a certain one you need to use i would really appreciate some help thanx