has anyone ever ran their engines with an open exhaust. aka no cat or exhaust free open at down pipe. iam getting DC 421 ceramic in a few days and thought to have some fun and see what the car sounds like and if it makes a difference in power to run on open exhaust. anyone try it yet? just a thought before i put in the DC header. i thought i might as well try it for fun to see how loud it can get. lemme know what u think