Yet another exhaust manifold & uppipe thread
 

So I am going to install exhaust manifold and catless uppipe to my WRX. Problem is that the manifold collector outlet size is bigger than the uppipe inlet size. Will this be a major problem?

Manifold outlet = 57mm
Uppipe inlet = 48-49mm

That is a quite a big difference and there is going to be a wall where the exhaust gases are hitting. I would like to hear every possible opinion about this matter. Anyone using this kind of combo? Thanks in advance!

:wonder:

Thoughts? Anyone?