I installed a 1.8 rd motor in my buddies 84 GTI with the knock sensor
and it works great. A few advantages are that you can run higher
compression motors without worrying about it melting down. The
computer for the knock control has two ignition maps you can use,
Europeon (Hot) and North American (Cold). The base timing on a big
valve head, 1985 and up is 6 deg btdc and with the knock sensor and
Euro ignition map you can push your timing to 12 - 15 btdc. With these
two changes you get about 5 - 10 hp gain and when you use super
unleaded you can feel the difference. (you can also change to a Euro
ignition map in any CIS-E powered motor by cutting the jumper from pin
3 to pin 11 on the knock sensor control unit and don't forget to
advance the ignition) This is such an easy conversion, I would
encourage everybody to do it. As far as I know you must use a knock
sensor out of a 4 cyl car to make this work I don't think a 5 cyl will
work. If anybody wants more info on this just post a message to this
group and I post the info