V-AFC on a turbo 99Si w/ aem fr; fpr, walbro fp 255; stock 240cc inj.

[Carboy247]

what does the vtec unmatched mean on the V-AFC? im a little confused on how to operate the Apex'i V-AFC....
my setting on the vtec cor. Lo->Hi is at 5500 and Hi->Lo is at 5300
under the wide th pos. .....(50%) why is the hi-vtec set at 5300; and low-vtec set at 5500.... (kind of hard to explain)
basiclly what i want to do is bump the fuel up under narrow(10) and wide(50) throttle..... im running 5psi on a stock B16A (99 Si); i know im running lean cuz my plugs are light brown; taupe; than a week later white.....i start the fuel at 3000....+2 and going up by 3 increments....

[Carboy247]

HELP!!!!

[fug_mo]

what does the vtec unmatched mean on the V-AFC?
Taken from Apexi website:

Q: What does the V/T Unmt do?
A: When the VTEC engagement point is modified, the difference in settings require fuel correction. The VTEC Unmatch function allows this correction of fuel between the ECU VTEC engagement / disengagement and VAFC VTEC engagement / disengagement. Please keep in mind that any value entered here will be added on top of the Wide and Narrow Throttle Maps.


im a little confused on how to operate the Apex'i V-AFC....
my setting on the vtec cor. Lo->Hi is at 5500 and Hi->Lo is at 5300
under the wide th pos. .....(50%) why is the hi-vtec set at 5300; and low-vtec set at 5500.... (kind of hard to explain)
Lo->Hi means the rpm at which it switches from Lo cam to Hi cam (or from non vtec to vtec) ...Hi to Lo is the opposite..meaning when you drop back out of vtec once it switches on.


basiclly what i want to do is bump the fuel up under narrow(10) and wide(50) throttle..... im running 5psi on a stock B16A (99 Si); i know im running lean cuz my plugs are light brown; taupe; than a week later white.....i start the fuel at 3000....+2 and going up by 3 increments....
If youre going to use the afc for your fuel management(dont recommend),you should run the car on a dyno with a wideband o2...or at the very least,hook up a wideband o2.It'll be the difference between having a good running engine or coming back on here in a couple of weeks asking how to replace pistons.

[BluSiBoy]

Dude Don't use a VAFC for tuning, seriously, people eventually realize how much it sucks for turbo and end up buying Hondata or just a chipped p28/conversion harness/uberdata. If you want, I have a Greddy E-manage unit for sale, that would help much more than a VAFC also.

[Carboy247]

thanksTaken from Apexi website:

Q: What does the V/T Unmt do?
A: When the VTEC engagement point is modified, the difference in settings require fuel correction. The VTEC Unmatch function allows this correction of fuel between the ECU VTEC engagement / disengagement and VAFC VTEC engagement / disengagement. Please keep in mind that any value entered here will be added on top of the Wide and Narrow Throttle Maps.



Lo->Hi means the rpm at which it switches from Lo cam to Hi cam (or from non vtec to vtec) ...Hi to Lo is the opposite..meaning when you drop back out of vtec once it switches on.



If youre going to use the afc for your fuel management(dont recommend),you should run the car on a dyno with a wideband o2...or at the very least,hook up a wideband o2.It'll be the difference between having a good running engine or coming back on here in a couple of weeks asking how to replace pistons.

[Carboy247]

i appricate it..... but i already have a OBD I P72, OBD I - OBD II jumper,w/ Hondata S200. Im just low on funds for the tuning..... the V-AFC is only temporary for 1 month.... i'm only running 4psi of boost....AND STILL NO CHECK ENGINE LIGHT!!!!!! :thumb: Dude Don't use a VAFC for tuning, seriously, people eventually realize how much it sucks for turbo and end up buying Hondata or just a chipped p28/conversion harness/uberdata. If you want, I have a Greddy E-manage unit for sale, that would help much more than a VAFC also.

[BluSiBoy]

That's great man ! Let me know how it goes I'd really like to hear the experience another Si owner has had turboing thier car.

[Carboy247]

:thumb: That's great man ! Let me know how it goes I'd really like to hear the experience another Si owner has had turboing thier car.

[epic1si]

dude just get your stuff tuned. you gotta pay to play.

[fastcivicboy]

well just to let you know in low boost the afc hack actually advances your timing. This has been prooven over and over. 10 psi it actually works the best. I wouldnt recommend this with your application since you have a b16 and the compression isnt the most boost friendly. If you have a little bit of cash we could throw my wideband on your car and tune it with the afc. People need to buy their fuel management first in a turbo kit. It supprises me how people cheap out on the most important part of a kit. If I where you and you have hondata sale it to some chump and run Uberdata (completely free) with the money you get from the Hondata buy a wideband or have someone tune your car. By far the best thing you could do. -Nick