I currently drive a escort zx2. theres a mod that you can advance the timing of the car with potenimeters. heres the link for the install on the zx2. i dont know if is capable on any scions but its worth a shot. heres the link of instructions.

http://www.zx2racing.com/pages_mods/pots2.htm

 

yeah, I am not sure if it will work on our scions. The vvt-i controls the timing so any messing around with that would probably cause the vvti to act on it and correct it.

 

the zx2 has a similar system that uses VCT(variable cam timing) it is only on the exhaust side. it didnt effect the timing. its basically sending a false signal to the ECU for a short few mins. its not something that you leave on. once i get a tC i am going to be the ginnee pig.