Retarderd huh? you want to see who has more knowledge of cars. no f***ing sh** you lose torque when you take away backpressure, but oh wait, duhhh i must have forgot to mention, that only happens when you lose velocity due to a significant loss of backpressure. this happens when the dumb ass ricers put 3" exhaust on a 1.6 NA motor. Back pressure reduction is the key when having an effective exhaust, but only to the point when there is still velocity. The thing that is key is not really how little back pressure you can get but how little back pressure you can get while kepping the velocity up. thats why when people upgrade their exhaust system they tend to open it up to a larger diameter piping instead of smaller. Let this information soak into your little head and the next time you want to argue, get your s*** straight. Take a look at some dyno sheets for any car on the planet that has reduced the back pressure in their exhaust flow. What happens, uhhh more horsepwer, more torque and in some cases, better fuel efficency.
sorry for getting o upset but i really dont appreciate being called retarded when the information isnt correct