Nova: How to increase time to create instances?

I created an environment for test totally virtual and in such situation the performance is very poor. Everything is working, create volumes, networks, flavors, images ... the only problem is when I tried to create an instance. I don't think there is a problem to create the instance, the problem is the poor performance of test environment.

Question is: Is there any specific parameter to increase so that I could workaround the timeout when creating a new instance ???

---
Ventura