I was wondering if any other members have had any issues with installing an aftermarket clutch (Sachs...not OEM Porsche part) or turbos and the dealership trying to deny a warranty claim stating that the aftermarket part caused the problem?

 

It's been discussed frequently....with varying individual result.
Ultimately it comes down to the dealer and specifically what the event was (ie relationship to the mod). Sure, there are dlrs that would find a 'relationship' even if there wasn't any possibility of one.

My car is Stage 3.something and I had numerous warranty issues honered but, by the same token, I wouldn't have expected them to cover anything close to my clutch, my turbos, etc.

 

As GreggT said, there seems to be a lot of variability with respect to dealer attitude towards mods, and the potential to void warranty issues. I've heard (either on this or another forum) of voiding warranty for "squeeks and rattles" with change in suspension, and and also of performing warranty work on modded cars. My local dealer only sells Porsche factory parts (no aftermarket items), and I got the impression that any mods would compromise my CPO warranty.