vtec94civic

i was told to use a 91 integra LS computer, b/c of the better fuel mapping. and to use a MSD RPM activated switch to trigger the Vtec, i was also told by another person that, that it wont work, it will just make a vtec sound. ???? some one let me know whats the best way to activate the vtec.

will a vtec controller work, does it override the comp??

Andy

VTEC is engaged by the VTEC solenoid. An RPM activated switch will work by turning the solenoid on, but that's not the best solution. VTEC is not just the mechanical system switching over to the new cam profile, but also an increase in ignition timing and more aggressive fuel maps. The switch method will work, but you won't get either of those, so it won't make as much power as it could and potentially could run lean and blow the engine up (most likely just have poor performance)

A VTEC controller is a good solution. You can use it to turn the solenoid on and off based on RPM (same as the switch) but you could retune the fuel maps to work properly (you won't be able to affect ignition, so it's not perfect). This is a much better solution but will require tuning to get it work right (how much should you affect the fuel maps when the VTEC engages).

The best solution would be to use a P28 OBD I SOHC VTEC ECU. Someone (probably HASport) makes an adaptor harness that plugs into the pre-OBD in-car ECU harness then allows you plug the OBD I ECU in. It has a few wires that will also need to be added for specific features and sensors the OBD I engine will require that the pre-OBD will not. My friend used one of these is a swap he did and I was impressed by it. That is probably your best solution as you will be using the correct ECU for the engine. A VTEC/fuel controller (like a V-AFC) will also be a good addition to help tun the fuel maps even further but wouldn't be nessicary. Seeya.