ive been looking to put a cam in my dd, not sure what stage to get but i was wondering is a vafc gonna be able to make tuning adjustment for it? what do i need to do as far as "tuning" for a stage 1 or 2 cam? or do i even need anything as far as that...just cam gears?

 

i know noone likes the vafc but i have one so i was thinikng i could use it......its going into a d15b or a d16y8 btw. most likely the d15

 

I am not sure about cam timing. The VAFC will be able to "tune" your Air/Fuel ratio and allow you to alter the VTEC crossover. Like I said, I am not sure about cam timing

 

so the afc and a adjustable gear mabey?

 

Even though its frowned upon the vafc will be just fine for your a/fr tuning, and the adj. cam gear will do the job on the cam. A few degree adv. or retard, will move your power band either high or low and give you a few hp.

 

thanks, that was what i was looking for! btw....what makes the vafc so bad other than its kinda limited to what it can do?

 

anyone? bump

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Crx_Civic &raquo;</TD></TR><TR><TD CLASS="quote">thanks, that was what i was looking for! btw....what makes the vafc so bad other than its kinda limited to what it can do?</TD></TR></TABLE>

vafc's get a really bad rap because they are a hack. They modify the signal going to the ECU to trick the ecu into adding/subtracing more fuel.

If you are running basic boltons and dont want to/can't convert to obd1 a vafc is a great alternative. You can always find them extremely cheap used.

My si was tuned on a vafc and made 13 more hp as well as a flat a/f ratio and got 30+mpg city.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pgmfi.org &raquo;</TD></TR><TR><TD CLASS="quote">Why piggybacks (vafc, emanage) "suck":

Piggy Back controllers allow stock ECUs to do things that they normally can't do, like run larger injectors or deal with boost. Remember that piggyback controllers work by altering sensor signals before they get to the ECU.

Most of the time, the primary signal being messed with is the Map Sensor. This is critically important in a Speed Density car. The Map Sensor is used by the ECU to guess how much air is going into the car, and therefore how much fuel to supply in order to match airflow. When you "lean" out a car with an AFC, you are simply decreasing the Map Sensor signal - the ECU responds to the decrease in manifold pressure by supplying less fuel. When you "richen" a car with an AFC, you are simply increasing the Map Sensor signal - the ECU responds to the increase in manifold pressure by supplying more fuel.

The change in fueling happens for a reason: if you look at a fuel table, Map Sensor values correspond with columns. When you increase or decrease the signal from the Map Sensor, you are simply making the ECU use a different column than it originally would have used. (see Understanding Maps if you need some help understanding reading Fuel and Ign tables)

But wait, isn't the Map Sensor used for determining ignition requirements too? When you "lean" out a car with a Piggy Back, you also in all likelyhood advanced timing. When you "richen" a car with a Piggy Back, you also in all likelyhood retarded timing. Look at trends horizontally (as MAP changes) in an ignition table, and you will see why this happens. This helps explain why so many boosted cars running on the "AFC hack" have issues due to excessive ignition advance.

The bottom line: Piggy Back Controllers suck because you cannot independently adjust fuel and ignition. Any changes to fueling will produce a change in ignition too, and often this is undesirable. </TD></TR></TABLE>