In reading about this and a buddy of mine doing the mod, this lead to us talking. In your lower to mid range of the revs…for optimal power on motorcycles, some back pressure is good. It’s very popular and fairly cheap to put exhausts on bikes and generally you will gain power in the upper ranges but lose bottom end and mid range. Not that big of a deal on my bike since I don’t race it off the line, but it’s being raced in the upper rpm range. But for the car, most of the time you’re taking off from the light. So while you get more power from doing the ‘golf tee’ mod/trick to keep the valve on the second exhaust pipe open the entire time, aren’t you losing some power as well in exchange? Aside from sound, my initial guess would be that this mod will cause a decrease in power/performance. Any ideas?