Good God these things are loud. They did come in handy for one, and one purpose only. I have automatic transmission, so without that last gear I have gotten to a max of 140 mph on a 2 mile straight. The e cut out got me to about 145, so theres some power increase at the top, but a lot of torque loss below. Basically I had a fujitsubo style y pipe, and I cut the e cut outs into there. After about 3k-4k in third gear is when I push the button to open them because any lower its just not worth it.