The previous owner of my copper '03 SV1000S installed a full M4 exhaust system. The quality of the M4 is amazing! No regrets there. But the factory rear head-pipe has been worthless. Suzuki made it from black iron, and it's not made from round pipes...it's cobbled together from about fifteen pieces of rusty black, with terrible welds ALL OVER IT. The inside is NOT even smooth! So, it has been a thorn in my side since I bought it, and was keeping me from getting a power commander and having it dyno-tuned. Today I tore it apart! Whoohoo! It was a chore, getting the system apart without dropping the motor, but I did it! Now I will attempt to make a new one from stainless, or have one made. If anyone else is going through the same thing, get that black iron off soon! It actually rusted part of my stainless system. Hopefully it will buff-out, but I am sure it would have stayed clean if this had been done earlier. I was kind of thinking about powder-coating my system. Has anyone else done this? Is there any power to be gained by doing it? Well, if anyone is in the market, don't write-off M4 too fast. The tig welds are perfect and small, the SS is clean, light, and fits perfectly. It is all brushed, not pollished, which turns a beautifull titanium colour after it is used a little. Ok. Thanks for reading, and please let me know if you have had success with powder coating the exhaust. Thanks!