[Ben006]

I talked with a guy that have a 2006 cayman S with a TPC turbo pushing 400hp.
He told me that he never had any problem (he bought it used with the kit on it already).

The compression ratio shouldn't be a problem as long as you don't run too much boost.

BUT there seems to be many problem with cylinder cracking on N/A engines driven hard that a turbo isn't gonna help...

So, if you can afford it, and afford to eventually replace an engine, go for it! Must be a lot of fun!