has anyone attempted this? Currently running 77mm and 172mm crank pulley with no issues

https://mbworld.org/forums/w211-amg/...alculator.html
what kind of boost are your current setup producing?,im running 180/83 and get just under 17psi,above 17,5psi should result in limp mode as i understand (map sensor limit)

Most I saw was 17.4psi (1.2bar)

has anyone done more before with no issues ?

Yes, but you'd better have all the supporting mods and know what you are doing....There are several threads on different MAP sensors, injector sizing , tuning, etc.

You are getting marginal gains beyond 15 psi as you are beyond the efficiency of the SC....You better be running a Killer Chiller or ice box as your IATs will go through the roof and then the car will basically become slower than a good factory car. The core is also a limiting factor on how much air you can push through.

Sounds like a bunch of heat to me

I don't see the point of it. The top dogs here run 190-200mm pulleys. They have the fastest cars. What your asking is just to big to have Any reliability. A 77mm stacked with a 180 is pushing it past its limits. There was a guy a few months ago that stacked monster pulleys. Car was fast for 2 days and then the sc blew apart. Everyone knew it would. Someone has to press the limits so the rest know what they are. At some point heat out produces hp.