TT's just pack way more TQ. Healthy Stg V's push over 400ft/lbs of torque. Now back that with a stiff ass racing type of clutch and you can see where it might be an issue. I did most of the research and findings you might have found on here from some this year and last. A lot of it has to do with the materials used on that flywheel side on the clutch disc. Some companies use very hard components and are way to abrasive in the long run and heat the center plate on the flywheel to the point of wrapping. But don't think that they are not strong, they are not going to wrap over night or after racing more than a few times. They are made of steel and they are very strong, but in the case of people looking for more insurance, then Fidanza also offers that same Carbon/Steel insert you should have found on here that was talked about during those post on this subject as well. The fact of the matter here is more so for those that already have there wheels too, the Carbon/Steel insert was running around $100 when I got mine and the factory selling steel one was $112. But like I was saying, in the case of an NA Z, there not going to hurt even the stock wheels, for they are much stronger than most lower Stage TT's can give it.
