I got my hands on a older knock gauge it came out of an 89 TTA it was popular on them and the Grand Nationals. Anyway I got the gauge for free and it works. Im not sure If its possible to put in a GTP and make it functional or not. Ive done some research and have not seen many people install this gauge and I know its set up for older cars that are not OBD2. I found the directions for it and not sure how I would go about hooking it up. I know about the + and - but im wondering if there might be a way to tie it into the PCM or hook it up to a knock sensor. If there is a way to get this gauge to work? It could be a new way to measure KR cheaper then an Aeroforce, I already have an Aeroforce so I would be able to see how it would compare to actual KR numbers. Just a thought because I have this gauge already and would like to use it if possible.
These are the instructions here
http://www.installationinstructions.com/102003.pdf
The model number is 102003 made by Caspers Electronics, Here is the gauge
