You cannot detect the added power? Man...it was instantly noticeable over here...my indy and other folks that have ridden in it pre/post 4.0l all commented on it. Sound wise - my buddy with the 991.2 said "it definitely sounds better than my car" and he has the PSE.

 

I can definitely feel additional *torque*. I am not sure how to distinguish *HP*, though. That's why I am putting it on the dyno -- to measure HP.

 

If you need pistons and or sleeves the cost to upgrade to 4.0 is negligible. Aftermarket pistons (we use custom CP) are the same price for either a 3.6/3.8 or 4.0. The sleeves and process to install them is the same. The difference is in the head gasket and we use a Cometic one.