Vteg02

This is on behalf of my friend...

Hi i have a 99 civic hatchback cx. i am thinking of buying an SOHC VTEC EX head off of one of my friends (only temperary,until i save for a real swap). my ECU is not programmed to hit VTEC. one of my friends said that i need a VTEC ECU. MY question is, instead of buying a VTEC ECU i heard you can just connect an APEX VTEC Controller to the CX ECU and it will be the same as the VTEC ECU...is this true or am i stuck having to buy a VTEC ECU...thanks

mobrep

you can use the vtec controller.

sohc_boy

i don't think u can use the vtec controller to engage the vtec. it is connected to the ecu and that is how it controls vtec it must be connected to the ecu if the ecu doesn't have a vtec output than how can it work? u can use an rpm activated switch to engage the vtec solenoid though which is a quick, easy and cheap way to control the vtec solenoid.

Trey

YES YOU CAN USE THE VTEC CONTROLLER.

Since the Fields and V-AFC control Vtec by sending the voltage to the Vtec solenoid, the ecu is not an issue. When you install a Vtec controller, you cut that wire from the ecu and crimp the Vtec wire to the controller. You can also use an MSD-RPM activated switch ($50) with the proper rpm pill.

The real issue is redline. Vtec kicks in at 5k and runs to 8k for the most part. Most SOHC ecus redline at 6800 or 7200 so you will lose the potential of the Vtec powerband.

sohc_boy

so than the vafc creates its own vtec output? it doesn't have to receive the vtec signal from the ecu and than out? the cheapest way to do it would be to get an rpm activated switch but like was mentioned your redline will be low. u might as well get a vtec ecu they are really not that expensive for the sohc vtecs. i saw ecu's at http://www.sohfast.com for 150 buks.