vafc

instead of buying the vtec ecu can u use only the vafc to engage the actuall vtec

What? If you're asking if you can use a VAFC to magicallly engage vtec in an engine that doesn't have it, then no. And just putting a vtec ecu into an engine that doesn't have vtec won't work either. If I'm off here let me know, but that's what I'm seeing your question as.

idk about the VAFC, but an AVC-R controller might be more what you're looking for.....

I think he did the LS Vtec and is wondering if you can activate VTEC without a the proper ecu. Mechanically, the answer is yes you can have an RPM dependent switch that manually operates VTEC (you can use a shift light circuit as the actuator) although you will need also a switch to deactivate it once it is on.

The proper ECU, however, provides you with the proper fuel and ignition maps, so unless you were using Uberdata, Hondata, or another chipping mechanism of some sort where stock fuel maps are inconsequential you may want to consider the hassle-free use of the proper ecu.