Unsung

Howdy. Picked up and installed my VAFC today. From what i've been reading and reviewing on the net about dyno tuning and results, leaning out the entire powerband makes the most power.

Yeah, I know I should have it tuned on a dyno, but i'm holding out until I get more tune-able stuff done to my car (fpr, camgears, etc.). If anyone has some basic tuning tips, that would be great. Thanks.

BTW>> the ride is a '00 Civic SI w/ AEM CAI, Skunk2 IM, DC 4-1, Tenzo Axle-Back (soon Apex WS Cat-Back). Thanks.

SpeedRacerEX-R

On my setup, 98 GS-R, I gained power by fattening it up. I'm running at 14.1:1 on the dyno and increasing gas up to 10% at 8k. OBDII sucks ***.

DragII

don't use anyone else's settings.

brcivic411

i agree. each car is different so you really do have to get on a dyno to tune it properly. I'm sure you could see some gains if you just took your car with the V-AFC. also, it's true you make more power as you lean out your fuel until KABOOM! it's better to be safe then sorry... running too rich will loose you power so you need to find a good balance between safety and power

94CivicSi

iTrader: (1)

can't be done without a dyno. Besides, it'll be good for you to get some baseline runs so you'll be able to compare pre and post mod results.

Just to reitterate a previous post in this thread, be careful leaning it out. The fuel/air charge provides cooling to internal parts of the motor. Go too lean and you're going to be burn up valve seats and other critical components.

Unsung

Apparently, my OBD-II won't let me lean it out more than 3% anyway, I think that is pretty safe. I had it at 4% today and it tripped code immediately.

DragII

hmm...that's not true, I had mine at -22% when I was using it.

Unsung

Well im not making it up. I can't lean it out anymore, it trips code. It all depends on the application on what the limits are for fuel tuning. My DX hatch I had at 20% and it didn't trip code. And now my Si won't go +/- 3%.

DragII

you sure everything is wired in correctly?

Unsung

Positive. Wired it myself. Followed the directions exactly for wire locations, distance from ECU, and all the shitty directions they give you. It's still only my second day having the thing, I'll play with it some more and keep you posted. But the guy I bought it from even said anything more than 3% on OBD-II.5 will trip code, so I don't know.

DragII

well, I'm not positive about II.5, my car is a 96 so it's just II. I've never hear that before, keep us posted. and good luck w/ it.

Unsung

Thanks for your help. I'm gonna go play with it right now.

Unsung

Just got back from playing with it. I'm not sure why it tripped code when I was below -3% last time, but it's not doing it now. I have it at -5% now, seems to run fine.

I think the reason it's flippin' out is because my 2nd 02 sensor still doesn't have a home, so it trips code after an hour of driving. A combo of that and my adjusted fuel curve probably pisses the ECU off quite a bit. I need to get that 02 simulator thing.

Petah

iTrader: (1)

Kind of off topic here but i have a GSR engine with ITR cams, intake, and exhaust. I was looking to buy a VAFC but i am not sure if i will gain too much HP out of it. Does anyone know approx how much power i will gain with the VAFC??

vpc

if you do a search on v-afc settings...you'll see that 100 times someone has asked this question and 100 times that person has gotten the same exact answer. Until you get yourself on teh dyno or get yuorself an a/f gauge. You cannot tune your car. That v-afc is a 300 dollar piece of eye-candy until you get the other things like fpr, fp gauge, af gauge, etc.