Project FD RX7 Restomod: Part 11 – Engine Disassembly

On the opposite side of the engine sits the extremely complex and tightly-packaged sequential twin turbo system.

With the heat shielding removed, you can clearly see the twin-turbo setup with the cold air compressors sitting at the very ends, while the hot turbine wheels are butted-up against each other and share a combined exhaust exit at the center, which connects to the down-pipe.

Towards the front of the engine (right side of the photo) are the two wastegate actuators that control the amount exhaust flow that goes through the turbine wheel and how much bypasses the turbo.  Below that, towards the center of the engine is another actuator that controls the sequential turbos.

With the turbos removed, we can see this third actuator and how it connects to this door that blocks flow to the rear turbo and diverts exhaust flow from both rotors to the forward-mounted turbo to improve spool, before opening up and sending exhaust flow to both turbos for top-end power.

When this door opens, it blocks off the bypass channel in the exhaust manifold and allows exhaust flow from the rear rotor to spool up the rear turbo when running in a twin-turbo configuration at higher RPM.

Removing the exhaust manifold from the engine, we can see the round exhaust ports that feed into the complicated exhaust manifold.