As one of the first new Cayman S owners ( American, living in England, USAF military) I made many modifications including an IPD plenum to the 3.4 engine which improved the overall performance and tractability . The Porsche is a "keeper" and the plenum performs faultlessly to this day!
Works well with the GT3 throttle body, headers, exhaust, and tune that I had on my car. Hasn’t and never will be on a dyno but feels quicker and that is all that counts in this 14 year old car.
Not being a mechanic the folks there were very helpful with instructing me through the process. Will re-evaluate doing the same to my ‘18 991.2 when it comes out of warranty.