Hi All couldn't sleep tonight so i decided to go outside and play with my VAFC. Experimented with settings fuel and so on. I used the settings that are floating around on the web most know which one i am talking about. Anyway this is what i tried. See below. I found some good results by using the below settings. No pinging that i could hear. So if you try the below settings your trying at your own risk. Please note this is an SS Auto not a 5 speed. Im trying to improve low end throttle response as well if it is possible.
Mods on this vehicle are as follows. Removed Resinator on intake. Running 2 and quater inch cat back exhaust with a remus on the rear end as well as my trusty APEXI VAFC. Running mobil one fully synthetic, NGK Copper plugs. No other modifications, pretty minimal.

Seat of the pants result. Throttle response does feel better, Once VTEC kicks in it pulls nice and hard.

Please note this has not been done oth the Dyno.

BEWARE TRY AT YOUR OWN RISK....

Would be intrested if others tried the below what result they acheived or if they can improve or suggest other settings. Yes Dyno is the sure way of tuning but i like to play.

1999 Honda Prelude Type VTIR Aussie spec could be SH

This was done at night intake temp was apx 19 degrees celcius
Apexi V-AFC Settings

Wide Throttle Narrow Throttle

Lo Camside Lo Camside
RPM Fuel Correction RPM Fuel Correction
1000 0% 1000 -10%
2000 -7% 2000 -10%
3000 -7% 3000 -10%
4000 -7% 4000 -10%
5000 -7% 5000 -10%
5500 0% 5500 -10%
6000 0% 6000 0%
6500 0% 6500 0%

Hi Camside Hi Camside
RPM Fuel Correction RPM Fuel Correction
4000 0% 4000 0%
4500 -7% 4500 0%
5000 -7% 5000 0%
5500 -7% 5500 0%
6000 -7% 6000 0%
7000 -7% 7000 0%
8000 -7% 8000 0%
9000 0% 9000 0%

VTEC Engagement Point Setting
Lo Cam -> Hi Cam: 4700
Hi Cam -> Lo Cam: 4400

VTEC Unmatch Fuel Correction
Hi<<L: 0%
Lo<<H: 0%

Throttle Position Setting
Lo Throttle: 10%
Hi Throttle: 50%

NE Point
LVt (Lo Camside) HVt (Hi Camside)
Ne1: 1000 Ne1: 4000
Ne2: 2000 Ne2: 4500
Ne3: 3000 Ne3: 5000
Ne4: 4000 Ne4: 5500
Ne5: 5000 Ne5: 6000
Ne6: 5500 Ne6: 7000
Ne7: 6000 Ne7: 8000
Ne8: 6500 Ne8: 9000


Best Regards

 

you prolly shouldnt lean it out that much before 3k. good idea to leave it alittle fat.

ill be tuning mine on a wideband dyno at 1pm today, i'll post my results.


[Modified by Crate, 3:02 PM 3/7/2003]

 

Ok can someone explain what the NE point is and how you tune it. I understand the rest of the tuning capabilites of the VAFC except for NE point.
And Crate I'd be really interested in seeing DYNO chart and what points you set the VAFC at after the DYNO. It would give me a better idea on how to use the VAFC when I actually go to tune mine.

 

I haven't looked at mine, but they seem like the reference points that you tune the fuel at. I wouldn't change it much from the stock values unless there's specific places in your band that seem out of whack.

though if people understand, can someone explain the unmatch fuel setting?

 

i understand that you like to play and all, but this is no playing matter.
i can't see those 3 sentances put together. tuning is vital here.
for starters, if your VTEC is set to engage at 4400RPM you are most likely losing some low end (very little though, and you're also losing some at the very top).
fuel is a very sensitive subject... i wouldn't really "play" with that. yes, most factory cars run a little rich so leaning it out a little won't hurt but you gotta know where to lean it and how much.
as you already know, dyno is the only way to tune it right. so do yourself a favor and do that.
as for your results, i can't see how you could feel it pull better... these are not big numbers we're talking about. and your right foot (alhtough probably heavy )is not a dyno so these things can't just be felt. maybe you feel it pull at one point of your power band, but maybe some other point is gettin really hurt... that's the whole point of the dyno tuning. you want to get your entire powerband tuned right in order to produce maximum gains, and this cannot be done without a dyno.
when i installed my FIELD SFC, and had it dynoed, i lost 1-2hp in the low range, lost 1/2hp way up top, but gained up to 12hp in the midrange at some points.
it turned out the most power was produced with fuel leaned out by 5% and VTEC engagement set @4600RPM. it took us 7 runs to get it to make that much. my mods at that time were i/h/e only.
but every car, depending on mods, will react differently to different settings. so if you hear of someone setting it to certain specs on their prelude, it doesn't mean those same settings will be ok on your car. the only way you will know how your car responds to settings and how much power you're making and where in the power band are you making it, is to dyno tune it like you said.
playin is cool, but you know what they say... "it's all fun and games until somebody gets hurt", and you wouldn't want your beloved H22 to get hurt now, would ya? DYNO

 

So BB1 if I dyno tune its basically just, testing the fuel settings in small increments (i.e. 5%-10% lean or rich) And you adjust the settings until you get the highest horse power or the best results.
Excuse me for the novice questions but I'd really like to and need to learn about tuning the VAFC.

 

yes, you try a few different ones, get the results, make adjustments where needed, and so on. but first, you make a base run with the VAFC off.
you wouldn't go by the highest hp. you have to review your dyno sheets and compare the base run to your new run to see how your powerband changed and to determine what could be adjusted differently to make more power. and same for every run after that.
most ppl think that highest hp is what counts. when i showed my dyno results to my friend, he said "what??? you actually lost power? what a piece of crap". that's because my base run had half a hp more than the last run. BUT, he didn't bother to look at the whole powerband. the whole powerband got some gains, as much as 12whp at some point. mid range was improved even better than i had expected, and the whole powerband was very smooth. this is what really counts. the highest hp doesn't really play that big of a role.
i don't know about the apex vafc because i didn't have any experiences with those, but FIELD SFC-VTEC definately works as advertised and its worth the pesos IMO. (if tuned properly)

 

So after I run a few different setting and I need to make adjustment how do I know if those adjustments are lean or rich adjustments? I know that if you run too rich to lose power and I know that if you run to lean the engine can blow (from what I heard.)

 

don't worry, they will know. just take it to a reputable shop that has experience in tuning imports.

 

My lude was dyno tuned in, the v-tec engages at 4200 and off at 4300, or did I say that backwards. I can post those results if someone would like, but the key thing is that every car, and I mean every car is different. Lot of luds don't like to engage till like 4600. Just my .02, pm me or email me if you want what I have in mine, mine is a 5sp, with header, exhaust, racing pulleys, and adjustable cam gears.

dom

 

Post your settings if you like im curious to see what they look like. Obviously every vehicle is different as we are all aware. As you are all aware i did specify try at your own risk. So it comes down to the individual if they take the risk or not. Onus is on them if something does go wrong.

Regards

 

I'm curious as to if the person that said their vtec was best at 4200 if they did the dyno with open header.

H22's with open exhaust seem to like a vtec xover of about 4200-4300, and with an exhaust, they seem to like 4700ish.

 

no offense man, im just tired of seeing this thread. so i made one for all vafc questions.

https://honda-tech.com/zerothread?id=435954

Doug

 

why do shops charge so much for installation? i know a guy that does work for 80hr. how long does it take to install a VAFC?

 

I'm the guy with the 4200 ingagement, and it was dynoed in. I have all the dyno sheets as well. I have a header and exhaust.

 

do it on the dyno. we ended up taking like up to 14% off the top end cuse i got REALLY fat above 6k rpm's. and yours could be way different (as bb1 said, he ended up only adding 5% in some places) i trimmed only 1% down low and added some fuel around 4k. from about 5.5k to 7600 i stepped it from -5% up to -14% in some places.

so ya.. dont do it yourself. i can write down all the #'s but i dont recommend you use them..

i actually only gained 4whp from the pull. my baseline was 176whp. ended with 80whp. but smoothed out my top end big time.

https://honda-tech.com/zerothread?id=436259


[Modified by Crate, 4:44 PM 3/8/2003]

 

yeah, we need more of these for other questions too...