Hello!
Just to be shure: You are using JAVA scripts?
if so, you can do the following:
Configure a short scenario in LoadRunner Controller with the script and only one virtual user. Run this script on a separate load generator. When you run the script from the controller on the load generator, go to this load generator machine. open the "jconsole" from the JAVA installation on this machine and connect to the correct virtual machine. Observe the usage of resources while the script is running. The allowed maximum values are also shown in jconsole so that you can see how much is used.
If you need to change the settins you have to go to the runtime settings of the script. In the section "Java VM" you can give some more resources in the line "Additional VM parameters". For example "-Xms32m" and "-Xmx200m".
The values to succeed need to be found by yourself.
Regards
Thomas