whats diff, some are open at top where it joins turbo, others have a blanking plate then pipe.??

 

Exactly the same question was asked the other day, as it happens:-

https://www.scoobynet.com/general-te...0-exhaust.html

 

you've answered your own question

 

Ha ha, yes he has... However, I'm sure he means what's better and why, etc (see above posted thread)...

 

i mean performance wise.

 

Well, I'm not sure if anyone has done a test comparison, but, logically, the bellmouth should easily be better for performance IMHO (i.e. bhp, torque, responsiveness), because the WG gases don't have to turn through two very restrictive 90deg turns, before joining the exhaust gas stream. To what extent though - who knows?