The YouTube Channel Cleetus McFarland has tried a weird little test with a group of 12 exhaust whistles. The theory is that the the exhaust gases passing through the whistles should make them scream. With 12 spread between the four exhaust pipes on a 841HP Corvette, there should be a really big noise, right? At first nothing happens, literally nothing. There just isn't enough pressure forced through the whistles. Jump ahead to the 10:00 minute mark when they pack towels into the tail pipe to jack the back pressure even higher.