APEXi S-AFC vs V-AFC

CNibbana · 05-22-2002, 03:28 PM

Both the APEXi S-AFC (page 23) and the V-AFC (here) work on Honda vehicles, the only differences being the ability to control VTEC with the V-AFC.

I'm considering trying the V-AFC with my SR20VE. My only concerns are if the V-AFC is Honda specific because of speed density vs. MAF. I'm thinking not only because of the wide variety of vehicles the S-AFC will work with including Honda.

On page 11 of the V-AFC manual the instructions are given on wiring and it appears the solenoids can be wired directly. The only negative is that the solenoids could not be seperately controlled. Both the intake and exhaust cams would have to be triggered simultaneously as the V-AFC only has one trigger. I'm still debating whether the V-AFC would have valuable application. If I can get a good JWT program I would say no.

What do you guys think?

skyliner · 05-22-2002, 03:47 PM

You CANNOT use the V-afc on our cars. The V-afc doesn't have a option for selecting a MAf sensor, the voltages curves on a MAP(pressure) vs MAF do not correlate. This was a option I considered when I started planning to go VE, I am considering running a S-AFC on top of my JWT ECU if they don't get the bugs worked out. I haven't decided if I'm running my solenoids synchronous (at same time) or asynchronous (different). Andreas suggested running it on a dyno without switching the cams, and looking at the torque curve. Then set the intake cam to come at what ever RPM the torque started to fall off. (ie right after peak torque) Run it again with only the intake switching and then set the exhuast to come on where the torque falls off on that run. Anyways that's my $1.50 worth.
Travis

CNibbana · 05-22-2002, 04:10 PM

Well this was exactly the information I was looking for. Thanks!!

SucKit · 05-23-2002, 01:11 AM

If your looking for a trigger, you can try the msd pills. Its exactly the same thing that is used to trigger the the shift light on Autometer tachs or rev limits on the Msd ignitions. Its cheap and effective, and nothing more than a switch that is activated at a certain rpm. It goes in 500rpm increments which can allow you to tailor when your cams to kick in. Its cheap and effective, but your not looking for cheap.

bigtom · 05-23-2002, 02:52 AM

razo has a two stage shift light that i have used before and it works fairly well. but has to be wired throught relays because it does not drive enough current to actuate the solenoids. it doesn't seem to have an incremental limt such ...like every 100rpm. seems to be completely variable

CNibbana · 05-23-2002, 09:02 AM

I'm already using the MSD trigger with the MSD dial potentiometer and it works fine. I was just considering the AFC because of the ECU problems we're having.

Shoes59 · 05-23-2002, 09:59 AM

Quote:

Originally posted by CNibbana
I'm already using the MSD trigger with the MSD dial potentiometer and it works fine. I was just considering the AFC because of the ECU problems we're having.

I considered the AFC unit till I discovered the problem is not the A/F ratios in the JWT ECU. The major problem (at least for my ECU) was the timing maps and to my knowledge you can't change the timing maps with an AFC unit.

SucKit · 05-23-2002, 10:23 AM

Yea but you can change it with an Apexi ITC which is the Ignition Timing Controller. What you guys really need is Greddy E-manage. It controls, Vtec, aspects of timing, fuel ,injectors sizing. http://www.takakaira.com/performance...age_frame.html Its definitely a viable options since it should be 10 times better than the AFC considering you can tune with a laptop. All for $300-600??

Yellow4g63 · 05-24-2002, 05:30 AM

660 for everything and u get the cable and software and u get rid of ur maff and run a map sensor if u want. it will control the vvl too.... well vtec should have vvl control since it's new.