Which race muffler is the best to use ? Which ones don't hurt performance ?
what is the part number on your mufflers?Dual 4" Magnaflow race mufflers on my car (the longer ones). The exhaust system adds 45 pounds to the car but it's better to hear things in the car while going down the track and not have ringing ears at the end of the day than to worry about the slight ET loss from carrying the extra weight. Some of the loudest cars at the track are also the slowest. Many of the faster cars all run mufflers now. Race muffler technology has come a long way in the last 40 years that there's no reason to run open headers any more. Race mufflers are not restrictive and don't reduce the engine power. As stated above, some engines will actually make more power with mufflers.
Without my mufflers, I needed ear plugs to just back the car out of the garage. Even the starting line crew say my car sounds great at the track.