Originally Posted by Happy

It definitely depends on what ones primary goal to leak exhaust is.

If I were going to leak my exhaust on a naturally aspirated M54, I would want both banks to vent. Also, I would highly recommend a Afe cold air intake as well, and a shark tune for the appropriate fuel octane rating.

Now for the venting. Once the tune is installed, I would figure out when my DISA actuates. If my memory serves me, it’s a bit past 4000 rpm on an M54. When the valve changes position to shorten the runners, bam! That’s when I would open the valves and run it all the way to redline! Or if on a highway, drop a gear, open the valves, punch it and make a pass.

For sound only, I could be wrong, but I would think a custom exhaust would be a better suit.

For forced induction, I would vent constantly at all RPM ranges when getting on it (Carving Canyons). It has been in my experience the more flow the better. However, I’m sure the power band would be affected, and shift points may need to be adjusted accordingly.