Resource Governor not limiting CPU / RAM
If you want to limit the CPU of a resource pool then you need to use the CAP_CPU_PERCENT setting:


  This settings is a hard cap limit on the CPU bandwidth for all
  requests in the resource pool. Workloads associated with the pool can
  use CPU capacity above the value of MAX_CPU_PERCENT if it is
  available, but not above the value of CAP_CPU_PERCENT.


The MAX_CPU_PERCENT setting is designed to limit the average CPU usage. If there isn't contention on the server then it can be ignored:


  If there is available CPU capacity, the workload uses it up to 100
  percent. The maximum value only applies when there is contention for
  CPU resources.


You can read more about different resource pool settings in the documentation.