i've got a 90 obd0 civic si hatch, with a 93 d16z6 in it. right now im ghetto and have vtec on a switch. i have the stock ecu. i have read that i can use a vafc to control vtec, but i also read that you have to have a vtec ecu for it to work?

im looking at buying either a vafc, or just an safc (going turbO) and i need to see if i can use the vafc with my non vtec ecu

 

you need to get the correct ecu
it has more than just the magic vtec switch
it has diffrent fuel maps for vtec wich will make more power and extend the life of the engine. because im willing to bet your running lean in vtec, and lean is bad.
you could damage the engine without using the correct ecu.
so that 300$ you were gonna spend on a vafc, spend it on the ex/si ecu.

 

to do that i'd have to go to obd1 which would be quite a bit more money.

i think i'll just get the safc, put vtec on a rpm activated switch, and tune for it.

i think it could still work, yes it does have different fuel maps, but the fuel system is based on vacuum, and it would automatically add more fuel to the car while in vtec because there would be greater vacuum.

its like putting a hot set of cams in an ls. usually you dont change the ecu for it.

i think i could make it work. it would still thikn there were separate vtec maps, but i would just be editing the normail fuel maps for whatever it was set at and up...

hmm, i'll have to think about this

 

REALLY? I was always under the impression that a VAFC was able to create new fuel maps for your stock ecu. Cuz When I was at the shop that did my swap the other day I was telling them that I was thinking of going OBDI and they told me it would be a waste of money and that a VAFC would take care of my fuel maps and vtec activation. This way I could save money not having to buy a new dizzy, injectors and ecu. Along with the conversion harness. That comes out to a pretty nice lump of cash

 

just using common sense on how an engine works, and how a vafc works, you should be able to use it to activate vtec. even if it doesnt create any nonvtec fuel maps, when you are usually above 4500 you want vtec fuel maps anyways. so if you just set it up so the fuel is a little richer at whatever point you set vtec and higher, it would be like creating vtec fuel maps.

that probably doesnt make sense, but i'm buying a vafc.

 

you can use a vafc but you have to have it tuned! most people will just set vtec and leave it alone.

the vafc can trick the ecu into thinking more air is in the combustion chamber and then it will adjust for more fuel. but just because your running a vtec switch dosent mean your getting more fuel.

 

Mike let me know and I'll get you a V-AFC for cheap.....guess who?
pual Vu

 

so basically when i add the 1.7 vtec head to my 1.8 all i would need to do is install the head then get the vafc ? i heard something about it the vafc not controlling the secondaries

 

ttt

 

i think the vafc only controls vtec activation, from the low cam to the high one...and not really any other aspect (ie: opening the butterfly on a gsr manifold)