A few weeks ago we showed you a wild 20B powered Mazda RX-8 street car built by Promaz Automotive. Well here’s another late model Mazda using and older style rotary engine this time in the way of a 13B twin rotor Cosmo engine. The RE engine as found in the JC Cosmo is similar to that of the Series 6 RX-7 but features larger secondary ports.
Fitting the engine is a Promaz bolt-in cross member while the engine itself has been freshened to a turbo bridge port specification. The factory twin sequential turbochargers have made way for a single Garrett roller bearing unit mounted on a custom manifold with boost governed via a Turbosmart wastegate. A switch to E85 pump fuel has enabled an increase in boost, but as the stock RX8 gearbox is still in place the guys have opted to a more forgiving organic single plate clutch.
Mazda RX-8 by Promaz Automotive
Promaz 13B-RE Cosmo turbo race bridge port engine
Promaz custom bolt-in cross member
Garrett roller bearing turbo charger
Turbosmart 50mm wastegate,
Turbosmart eBoost Street electronic boost controller
Promaz custom E85 fuel system with Bosch 044 pumps
Promaz custom inlet manifold, intercooler and piping
Promaz billet crank angle sensor adapter
Exedy heavy duty clutch with organic plate
Factory stock RX-8 gearbox
Simmons 22in gold plated wheels