The Racing Beat REV8 "street legal", cat-back exhaust system for the 2004-08 RX-8 is a quality replacement for your RX-8's stock exhaust. Racing Beat's system includes all stainless steel muffler canisters, tubing, flanges, and outlet tips. The 304 stainless connecting-pipe is manufactured using 3-inch (OD) tubing and cast stainless steel flanges providing positive exhaust gas sealing as well as minimizing the chance for gasket failures. The stainless steel muffler canisters are each finished with 4-inch, polished 304 stainless tips for an aggressive look.................
Utilizing our in-house dyno test facilities, the Racing Beat engineering staff has undertaken extensive exhaust system testing with the RX-8 Renesis engines. Our research has found that simply adding a large-diameter, "straight-through" muffler is very loud, and power gains are only modest. We focused our development efforts on optimizing the power output, while maintaining a moderate, but aggressive exhaust tone.
Based upon our initial test sessions, it appeared that the Mazda engineers did not leave much "untapped" horsepower behind in the stock exhaust system. Although it appears there might be modest power gains available from a "cat-back" exhaust system, be wary of big horsepower claims from any aftermarket exhaust system.