My project car is a 90 rx7 2nd gen streetported w/candem supercharger 12 psi . So my concern the noise , so what's best for me for exhaust RB or else .

thanx

 

Welcome to the forum.
I hope you already know 12PSI is dangerously high without an intercooler or water injection.
A RB header will help that setup a lot with power, but you're right, it will be LOUD.
The long RB pre-silencer is about as good as they get. It will take the heat.
After that you may want to try 2 mufflers in line.
-Bill