Ok... I finally have decided to make a fuel adjustments to my 00 ITR. I have a Apex-i V-AFC installed for the last 8 months, no problems...

I want to baseline the ITR on the Dyno before making any adjustments, however, I do want to increase the fuel pressure with the Apex - i.

First off, what is the stock pressure the ITR is running.
Sencod, what would be an acceptable increase?
Thrid, How the heck is it done throught the Apex-i's GUI?

Regards,

 

You do not increase fuel pressure with the VAFC but the injector duty cycle in percentages through RPM range (500 RPM increments).

To accurately do this find out what the ideal mix first your target ie. 13:1 Fuel to Air, and try to hit that mixture through the RPM range using a Lambda meter. I think there is one dyno in Toronto that has the Lambda meter.

5HP increase I would imagine would be pretty good for fuel tuning on a stock ITR.

Another method you can try is to tune while viewing the O2 sensor voltage while driving the car as well feeling the after affects with the butt dyno. This is not the ideal way but it worked a bit.. Not entirely effective since the O2 sensor on stock cars have a very narrow band.

 

Not to mention that as the pirmary 02 heats up, it will change you readings. Just as when the engine heats up, it will also make your settings vary.
Reading your promary 02 is a very rough tune. Will save you a little time at the dyno, but not much.

Jason

 

Does anyone have any info. or personal experiance with the Greddy A/F meter that comes with it's own O2 sensor? Is it any more accurate than the other digital meters like autometer( )

 

AFC has NO control over injector duty cycle whatsoever.

You cannot richen with the AFC only lean. You need an adjustable fuel pressure
regulator to richen the mixture. Increase fuel pressure slightly. See where
power increases. wherever power decreases you lean with the AFC.

 

I was under the impression that + and - adjustments could be made at each adjustment point.
Does the V-AFC have more control than the AFC? Other than VTEC engagement point movement?

Willie
-who is now confused

 

Hate to disagree with you, but this is not true. You can richen the mixture with a V-AFC. The unit allows +/- 50% adjustment (but really it's probably more limited by when your ecu would throw a code)

 

AFC alters the signal from the MAP sensor.
If the map sensor is already at maximum 2.8Volts, then the AFC cannot do
anything to richen the mixture. It has no direct control over injector duty.
You can set it as far into the positive you want to, you arent guaranteed that
ANYTHING will happen at all.

 

There you go sgT, that's more along the accuracy I expected to hear from you.

According to hondata:
- On a B18C "The stock MAP sensor can be used to read up to 11 lbs boost."

I'm not sure what that translates to as far as fuel delivery is concerned, but I would be very interested in finding out the percentage relative to stock if someone is clever enough to do the calculation.

Anyhow, as far as the application at hand, I would definitely recommend a VAFC if you want to modify your fuel maps with a stock internal setup. It may not be a value for the money mod, but you may gain some performance. In my case, I gained by leaning slightly on the low cam and richening during VTEC. I also found my engine liked to the VTEC crossover at a different point from stock. Remember though, each engine's different.

 

The stock map sensor can be used to read up to 11lbs of boost.
The hondata is able to use the stock map sensor to read up to11psi.
Why 11? Because at 12psi the diaphragm in the sensor will burst.
HOWEVER, the stock ecu cannot see above 0 vacuum. It expects to see no
more than 2.8V at any time. That is why devices like the field come with
a voltage clamp to limit maximum voltage at 2.8 and it will tell you when it cannot
richen the mixture. And as i pointed out previously, if the motor is at or near 0 vacuum at WOT, then the vafc will not be able to richen.

You are not modifying any fuel maps. You really need to understand that.
You are just modifying vacuum readings. You are making adjustments on
the assumption that the vacuum readings at every rpm at wot are the same
every time, which they wont be.

Do not use these misleading statements.

 

Thank you for correcting me about mistakenly referring to vacuum readings as "fuel maps". I do find that vacuum readings at a given rpm @ WOT fluctuate (as does my car's performance) with weather & atmospheric conditions (ie humidity and barometric pressure). There's a noticeable difference, yet I wouldn't call my car's performance unreliable.

What I've learned from our discussion is that using a FPR (or ECU) to get the mixture as rich as you need it, with a VAFC to lean it out where appropriate should guarantee you the ability to tune your fuel curve to perfection. What I'll be doing tomorrow is seeing how close I am to 0 vacuum @ WOT during different rpm points to see if I need a FPR for my application.

Good info!