We have heard stories of the RX-8 generating less power than advertised from the factory. From our previous RX-8 test sessions, we have seen horsepower output ranging anywhere from 175 to 185 horsepower. Taking into account driveline loss, the RX-8 is rated much higher from the factory than actual power output. Our tester, a 2005 Mazda RX-8 with 26,000 miles on the odometer registered in at 180.85 horsepower and 128.00 lb-ft of torque. Based on a 15-percent loss through the driveline, flywheel horsepower checks in at 212 ponies.
128 LB-FT TQ
Test 1: Race Muffler
With baseline numbers on record, we moved forward and removed the factory RX-8 exhaust. As mentioned earlier, the stock exhaust weighs in at 39 pounds so an extra set of hands would be ideal. Unlike the stock exhaust that features a twin-outlet design through the bumper, the Racing Beat Race Exhaust dumps exhaust gases through a downward-angled outlet pipe. The polished stainless steel really stands out without signaling to the police that your car is modified. The race muffler installed without a hitch, with spot-on fitment. On the dyno, the exhaust generated an increase of 2.23 horsepower and 3.84 lb-ft of torque. At 3800 RPM, the race muffler made an extra five to six horsepower more than the stock exhaust. Peak power jumped to 183.08 horsepower and 131.84 lb-ft of torque.
131.8 LB-FT TQ
The Racing Beat Race Exhaust System is substantially lighter than the stock system. The polished stainless steel and downward-angled tip offers a different look than your normal modified exhaust systems. The higher-flow exhaust delivered an increase of 3.0 peak horsepower.
Test 2: REVi Intake System
Moving on to the second performance part from the Racing Beat trifecta, we installed the REVi Intake System. Removing the stock intake system required the removal of the front bumper. Once the bumper was off, removing the stock air box was straightforward. With the stock intake removed, the REVi Intake System can be installed. Installation of the system requires the reuse of one of the factory air flow meter mesh screens. The REVi Intake System is a high- quality piece with very detailed instructions and achieves a perfect fit.
With the Racing Beat intake installed the RX-8 was back on the dyno. The free- flowing intake system produced big gains throughout the powerband, pushing peak power numbers to 190.09 horsepower and 133.77 lb-ft of torque. Compared to stock, the REVi intake generated an additional 7.01 horsepower more and 1.93 lb-ft of torque at the respective peaks. With the REVi system in place, the engine really came to life from 6,000 RPM all the way to the 9,000 RPM redline.
133.7 LB-FT TQ
The REVi Intake System generated the largest increase in peak power of the three components. We witnessed the Racing Beat intake generate 7.01 more horsepower and 1.93 lb-ft of additional torque to the wheels. The intake helped to improve performance across the entire powerband.
Test 3: Catalytic Converter Replacement Pipe
Last of the power trio to be installed was Racing Beat’s catalytic converter replacement pipe (race pipe). Rotaries are known to generate a lot of heat and the catalytic converter is like a brick oven retaining a large amount of the heat generated from the exhaust gases. Before attempting to remove the catalytic converter, the vehicle should be properly cooled for at least an hour. Allowing the vehicle to cool will also lessen the chances of stripping nuts and bolts. A good penetrating lubricant is highly recommended on all hardware before removal. Removing the stock catalytic converter requires the removal of two chassis braces first. Once the braces are removed, the stock catalytic can come out. Installation of the race pipe can be installed in the reverse order of removal.
As expected, the race pipe generated good numbers at the top end of the RPM band. With the race pipe installed the RX-8 checked in at 196.56 horsepower and 133.71 lb-ft of torque. We gained over six peak horsepower compared to stock but lost a little torque. The race pipe also increased the volume of the full-throttle exhaust note substantially. The RX-8 now purrs at idle and with the accelerator smashed to the floor, the rotary engine screams.
133.7 LB-FT TQ
Last of the components to be installed was the race pipe. Removing the factory catalytic converter reduced exhaust backpressure and in turn produced more horsepower at the top end. The race pipe came in at a close second for highest power gain with an increase of 6.47 horsepower over the stock catalytic converter.