I have a b16 and a JRSC at 9 lb..... DC 4-1 header and 2.25'' test pipe connected to 2.36'' piping with an Apexi WS muffler.

Is this sufficient exhaust? Should I switch to something else? I don't care about 10 hp...but if it's like 20 or so that's more than worth it for me

 

??/

 

You will be fine, I have made 280 + whp and seen less then 3 whp dropping the exhaust. , and that was with a mugen twin loop.