i'm not sure what you meant by the DOHC being controlled by the computer??? its the computer that sends a signal to engage the Vtec solenoid and kick the pin to lock the rocker arms so the more aggressive cam lobes take over.

i believe that iVtec uses this method in addition to varying the timing far more by advancing or retarding the spark timing by +/- 20 degrees. with this new element, we can all see how the iVtec has lots of potential in tuning and why the Vtec cross over is smoother than regular Vtec.

anyone please add or correct... i'd like to know more advantages and disadvantages of iVtec... :goodjob: