Does anybody have any evidence on how restrictive the stock mufflers are? I am shooting for 1000+rwhp and was curious how much my stock mufflers are going to choke my power down, if at all vs. an aftermarket muffler. Its a turbo car and I do not like loud exhaust so I am not going to buy an aftermarket muffler. If anything, I will run some electric cut outs. The rest of the exhaust is pretty well opened up(no cats and mandrel bent exhaust). Thanks for any info.