I know this topic has not been touched in a while, but I have put underdrive pulley systems on numerous cars and NO car that I have put it has had adverse effects, especially the oiling system. Unless Toyota did something really unusual and made the oil pump belt driven rather than crank driven on the GT-S, the underdrive pulleys will NOT effect the oil being dispersed throughout the engine - the crank speed will remain the same with or without the pulleys, hence, the oil pump delivers the same amount of oil regardless.
2005 celica Underdrive pulley
in Celica Club
Posted
I know this topic has not been touched in a while, but I have put underdrive pulley systems on numerous cars and NO car that I have put it has had adverse effects, especially the oiling system. Unless Toyota did something really unusual and made the oil pump belt driven rather than crank driven on the GT-S, the underdrive pulleys will NOT effect the oil being dispersed throughout the engine - the crank speed will remain the same with or without the pulleys, hence, the oil pump delivers the same amount of oil regardless.