I know the motor came out in a s12 gazelle/silvia. I use to have some engine spec links on the motors. I found the following links to show proof they do exist.
http://www.geocities.com/mahl70/intercooler.html
http://www.geocities.com/mahl70/cars.html
http://www3.sk.sympatico.ca/ahodar/CA18ET.jpg
Engine Name: CA18ET
VIN: JN1C...
Design: Turbo, SOHC, Fuel Injected, Twin Spark Plug, 8 valve, 1.8L Inline 4
Bore x Stroke: 83mm x 83.6mm
Compression Ratio: 8.0:1
Horsepower: 120hp @ 5200rpm
Torque: 132lb/ft @ 3200rpm
Redline: 7000rpm
http://www3.sk.sympatico.ca/ahodar/variations.html
Blurb from one site:
From 1984-86, the 200SX was offered with two engine choices, the CA20E 2.0 liter four, or the CA18ET, a 1.8 liter turbo. It was in 1987, however that Nissan offered the U.S. market something more. The turbo was dropped and, in approximately 5000 cars in 87 and 5000 in 88, the VG30E 3.0-liter V6 was shoehorned in to create the 200SX SE V6.
All i know is, my mate had a 1600 with the ca18 single cam, and it whipped my 1600 with a z18et.
I have recently sold the motor/box setup to make way for a traditional l20 motor as a daily driver.
If anyone is interested in getting a ca18et setup for a 1600 let me know as my mate might want to part with the setup/car for cheap, around $1000 - $1200 dollars.
cheers
Martin