Internal Upgrades to the
RXX-7's 20B Engine
One of the important things about doing upgrades is to have some concepts in mind before starting. The 3D rendering of the 20B on the left is Mazda's concept. The warning on the right is mine.
"When life hands you lemons, make lemonade." When I blew an apex seal (or two) and had to have the engine re-built, I could have gone for a simple, stock re-build. Where's the fun in that? (Besides, most of the cost is in the re-build, not the upgrades.) Though not financially able to go all the way to a full single-turbo upgrade, I took care of the internal changes:
The housings.
The exhaust ports were opened up a bit. This is a nice before-and-after picture.
The irons.
The intake ports were increased, as well. Another before-and-after picture.
The rotors.
Some time ago, the racing community noticed that beveling the rotors gave a noticeable increase in power. Kevin offered to make this improvement, so I eagerly jumped on the chance.
This is what the stock rotor looks like in relation to the intake port. And this is with the beveled rotor.
Once the motor is completely broken in, I'll post dyno sheets for comparison.
All photos courtesy of Kevin Landers at Rotary Resurrection. 3D-3rotor rendering by user swimmer4uus on the rx7forum.