I bought my car and noticed the that the piping was a different size. From the turbo to intercooler it is like am 1in then from cooler to intake manifold it is like 2 1/4. Should I have the same size all around. What are the pros and cons...thanks ahead of time.

 

you're fine. depending upon power goals, 2.25 to 2.5 is more than adequate for over 500whp. As long as the cooler exchanged air to the throttle body is the same or larger than the one from the turbo to the intercooler, you're fine.

For additional information about intercooler piping air velocity and their diameters, look here..
https://honda-tech.com/forums/forced-induction-16/airflow-velocity-different-intercooler-piping-diameters-2-0-2-25-2-5-2-75-3-0-inches-1202591/

 

Larger piping = less friction = less heat from moving air.

Unless you're trying to move a lot of air from a large from turbo, you'll be fine with what you have.

May want to look into the 1" piping from turbo to IC though.... lol

 

I want all the same size so what be recommended

 

1" turbo outlet?? Go with 2 1/4 or 2" all around.

 

Im running a 1.5inch cone to 2inch piping. turbo to ic, then ic to intake is 2.5

 

Why change it if it's working for you?