Slowdown on upgrade to 5.2 from 4.5

We are updating a large application from Lucee 4.5 to 5.2
We seem to be loosing some performance.
Specifically in STARTUP, PARSING, COMPILING, LOADING, & SHUTDOWN and APPLICATION EXECUTION TIME

Any suggestions on what might be causing this?

4.5
|3.48 ms| |STARTUP, PARSING, COMPILING, LOADING, & SHUTDOWN|
|568 ms| |APPLICATION EXECUTION TIME|
|3243 ms| |QUERY EXECUTION TIME|
|3815 ms| |TOTAL EXECUTION TIME|

5.2
|133 ms| |STARTUP, PARSING, COMPILING, LOADING, & SHUTDOWN|
|1069 ms| |APPLICATION EXECUTION TIME|
|3102 ms| |QUERY EXECUTION TIME|
|4305 ms| |TOTAL EXECUTION TIME|

Total difference is ~500ms (half a second) and 4/5 of that is in your Application Execution Time. Would need to know more about your code to even make an educated guess as to why.