I'm trying to decide if I want to go with dual cutouts on y-pipe for an open headers kind of approach or if I want to just put one single cut-out just after the y-pipe. I know the 2 cutouts would be louder but what would the performance difference be?

 

i'm trying to figure out the same thing....

ttt for ya

 

Ok here's what I have so far.

Dual cutouts will outflow the single cutouts... but when they are closed there will be a lot of turbulence which is bad. Dual cutouts will also produce less torque, I'm told, do to there being little to no back pressure. REALLY LOUD!

Single cutout won't flow as well and creates less turbulence when closed. Still flows pretty good (better than any muffler set-up). Better torque than the duals, or so I'm told. Nowhere near as loud as dual cutouts.

Conclusion:
?????????????????

 

I dont think dual cutouts will make you loose torque, it will just sacrafice low end for top end. You really have to think about what you want, how your car is geared and how you drive it. With the ls1 being a top end beast, i would opt for the dual cutouts, especially if you had some low gears and an m6.