I kept looking on line for an answer to my rpm question and found what I was looking for.
For the record,
Our factory test runs all the engines before they are sent to the customers. The max RPM in the manual is just that, a not to exceed RPM. Even though each turbine comes from the same parts, no 2 turbines are identical. That's why when a customer sets up a twin, he will have me match the thrust outputs on the test bench to fine tune them. Most every engine I test, usually puts out a tad more than it is suppose to. The Early K-80's had a completely different internals than the current versions. The earlier K80's used a "J" tube injector and the new 1's use needles. The factory made the change to make the engine even more reliable and more fuel efficient. The turbine in question was tested at the factory and the factory intentionally locked down the RPM because the engine was making the proper thrust at that RPM. If they left it higher, like Barry said per the customer, it is for safety reasons you don't want the engine over producing what it was designed to do. The good news about that engine is you are getting max performance and using less fuel, less wear & tear, due to lower RPM.
Hope this helps clear things up?
Dirk
KingTech Service