vtec controller

[kyle34]

has any body had any experience with the apexi digital vtec afc controller if so i was wondering if i could find out a few things

[SleeperCivic]

Probably wouldn't do any good without changing the injectors out. With a N/A motor, you'd probably be better off going with a stand alone managment unit.

[kyle34]

if i do that and get it i noticed that you could change the fuel and pressure on it do you have to ajust all that every time you change the responce of the vtec i really apreciatte the help

[SleeperCivic]

I'm not sure about the fuel pressure, but I know you can adjust the injector duty cycle (highly recommend bigger injectors) to supply more fuel at different RPM's and also change your VTEC engage RPM point.

[luti]

He's right, you can't adjust the pressure, just the cycle. I used my butt dyno to move my VTEC down to 5000 and to turn off at 4000 and played a bit with the fuel maps, it really does help, but yes, bigger injectors would come in handy. If your going to get the V-AFC get an Air/Fuel gauge, trust me, you'll need it.

[92hatchatack]

to that list id add a fuel pres. regulator and a fuel pres. guage----also apexi's vafc is on sale right now for$305---one of the best prices ive seen in awhile

[SleeperCivic]

Why do people insist on recommending a FPR?? You DON'T need one!

[92hatchatack]

ummmmm are u kidding me???fpr is a very recomended mod if u ask me---and most other people will tell u the same---sure u can use stock psi----but once u start puttin more air throught that engine i highly recomend bumping that up a little

[SleeperCivic]

I agree on using different fuel modifications to compliment the extra air flow, but not with a FPR. Your stock fuel pump can only run efficiently at certain pressure adjustments. That's why you can look around and see most turbocharged imports running aftermarket fuel pumps. No FPR required and you get the reliability of high flow, not high pressure.

[92hatchatack]

better flo is great, but doesnt it take pressure to force the fuel through the injectors----your saying you would run stock fuel pressure on larger injectors????i guess our opinions differ then---

[SleeperCivic]

Yes, I would. The VAFC will control the pulse width of the injectors, which supplies more fuel (combined with retarding the timing). The amount of flow, not pressure, would determine the amount of fuel.

[B16EJ1]

Originally posted by luti
He's right, you can't adjust the pressure, just the cycle. I used my butt dyno to move my VTEC down to 5000 and to turn off at 4000 and played a bit with the fuel maps, it really does help, but yes, bigger injectors would come in handy. If your going to get the V-AFC get an Air/Fuel gauge, trust me, you'll need it.

I don't understand what you mean. You changed your VTEC crossover to 5g. Why would you do that? You do know that with a lower crossover point you lose hp right? The cam profiles are made for the factory crossover at high rpms. That's what VTEC is for. If you chang the crossover point I suggest you push it back a tad. But hey I may have read your post wrong.

[92hatchatack]

dont u need an increased amount of pressure with bigger injectors for them to actualy spray corectly--i understand what u mean by better blow--

as far a vtec changeover---- ive seen people have very good restults on itr-ctr cams with a changeover point around 4900-5000

[B16EJ1]

I don't mean hp loss overall. There is a dip in hp at the crossover. You want a consistant gain on the dyno and with the lower crossover the dip is inevitable.