As for the crank pulley. It works as neil_cb125t said this isn’t new. The removal of rotational weight off the flywheel and crank help the motors ability to spin with less resistance. There is a hp and Tq gain but its not something you can easily measure. The best part is the JHM crank pulley really shines in transitional power. like your part or low throttle and your wanting to scoot though traffic. There is less load or chug on the motor with the reduced weight.
Why would you want to replace your stock dampener from your S6 or S8. Well the technical bulletin gives the same talking point about this part for the past 10 years and every OEM Audi dampener I have ever seen other than ones on cars that are practically brand new are broken… seized… or completely failed and falling apart.
The rubber cracks just like the other rubber hoses on the motor and the ability to actually dampen breaks just like the intake manifold flaps do. Several people think the front main is leaking when it turns out the dampener has been leaking out fluid and is now dry and just useless.
Even cars as new as 2015 3.0T S4s with the supercharged motor we seeing there dampeners actually ripping apart and falling off the car. http://audirevolution.net/forum/index.php?topic=3239.0
The OEM dampeners have had these issues since as long as I can remember. I replaced mine 8 years ago with the JHM unit and have had no issues. This isn’t just a 5.2 thing the list of guys who have done this is extensive. This isn’t just something that JHM tried on the S6 and S8. I’ll see if I can do a search and find the guys who did a oil test to see if there was any signs of extra ware with the JHM crank pulley over 5 years of use. They found no difference in ware but a pleasant bump in acceleration and response
Check out the actual results from across the board. JHM makes crank pulleys for
the
3.0T
RS4 - 4.2
S4 4.2
S6/S8 5.2
A4 2.0
RS7 4.0T