It had a compression-reducer plate on the heads, so it only had 8.5:1 compression. Here's the link where I bought the package - installed it myself, the Stage 1. (Note: The package shown now is seperate from the one I bought - the one I bought wasn't as powerful, only bumped me up to 275HP). The picture shown is a turbo beetle, but it's the same setup as you would use on a Jetta.

http://www.hpamotorsports.com/golfjetta.htm