Was wondering what the pro's and con's of having open headers

I have a lt1 with 11.9to 1 compression
200cc AI heads intake
238/242:580/603 on a 107lsa
Really not caring about loudness as this will be a track car only

Thank you

 

Years ago there was a big debate on here about back pressure, which I don't think it showed it necessary. My car seemed to do better with the cutout open but only like half way. Anymore and it affected performance, or seemed that way. Wanted to do a test and see if any knock was picked up with it fully open.

 

If you're running a closed loop tune, and relying on the O2 sensors in the collectors, the backwash of air can make the sensors read "lean" and cause the PCM to make it run rich. With an open loop tune, this becomes a non-issue.