Here's a toughie:

Does anyone know how the fuel lean/rich percentages on a V-AFC translate to actual figures on the ECU.

I dyno-tuned my V-AFC on my OBD2 ecu with nice results. Now I want to burn my obd1 ecu w/ similar fuel curves. I'll still have my V-AFC hooked up (at some point), but I'd like the bare ecu to be at a good startin point.

I have things leaned out as high as -11 on the fuel curve. How would you translate that into burning hte ecu???

The more detail, the better

thanks

 

 

its a percentage of the original value...so simple math ought to do it.

-dw

 

first you would have to know the fuel maps in the ecu.
Then you would need to know what vacuum range you were running when you tuned.
You would then convert those vacuum readings to voltage readings and then
subtract the percentage that the VAFC was taking off.
Then the resulting voltage reading you convert back into vacuum and then
figure out where on the fuel map you ended up.

Does this make sense to you?

 

not remotely

I knew the values on the V-AFC weren't accurate--I didn't know that I'd need to be able to do fractile geometry in order to translate one from the other.

Keep in mind, I know nothin gabout the science of ecu tuning.

Thanks for the insight, though--maybe the guy who is burning my program can make sense of it...




[Modified by gamby, 11:50 PM 1/21/2003]

 

lets start with something simple.
do you know how a vafc works?

 

good post.

 

whats an OBD1
and OBD2

 

whats an OBD1
and OBD2
could i just use the VAFC and cam gears to dila up some ITR cams??

 

_______

In terms of actual mechanics, no.

I'm assuming I (moreso the programmer) will be starting from a stock B16A2 program and modifying it from there.

I'd have no idea about vacuum and voltage readings.

You're welcome to through the trouble explaining it, but I'm only concerned with a potentially simple issue: "how far off are the V-AFC percentages, and in what way?"

Otherwise, it's all Greek to me.

BTW--DW--what the hell are you still doing on this board???


[Modified by gamby, 5:13 PM 1/22/2003]

 

There is no programming involved with an AFC.
The way the AFC works is it modifies the map sensor voltage to trick the ecu
into reading from a different part of the fuel map. The reason why it doesnt do
well at richening the mixture is at wide open throttle, sensor voltage is usually
at maximum and increasing it anymore will not do anything and can cause
the ecu to think that the map sensor is defective.

A little less greek?

 

Gamby, if you are getting a hondata set-up, which I assume you are then your last dyno run with the A/F ratio and the corresponding sheet that lists the A/F ratio per 100 rpm should do the trick. If someone has the stage 4 to tune the hondata and a wideband then you can just punch in the A/F you want per range of rpm and the hondata software modifies the ECU settings to get your desired A/F. Haven't seen it work yet but it but it must be pretty cool.

s

 

Steve--Actually, I have a blank hondata-socketed p28 that needs to be burned. I went this route so upgrading to full-on hondata would be an easy option.

sgT--makes sense now. I guess trial and error will be the key w/ burning the program. I'll just err toward the rich end of the spectrum.