Holy shit. I knew they were going to simplify Raptor a lot, but even knowing most of the rat's nest was sensors/etc., this is insane. I wish we could see cross sections!
The amount of work required to simplify the Raptor engine, internalize secondary flow paths and add regenerative cooling for exposed components was staggering.
As a result Raptor 3 doesn’t require any heat shield, eliminating heat shield mass & complexity, as well as the fire suppression system.
It is also lighter, has more thrust and has higher efficiency than Raptor 2.