SpaceX cut the Raptor engine from a tangled mess of pipes to a sleek design while gaining 35% more thrust, mostly through changes to the fuel and oxidizer preburner systems and plumbing routing. The article pieces together what likely happened using fan-made schematics and occasional comments from Elon Musk, since SpaceX keeps the actual details classified.

• Raptor 3 delivers 35% more thrust than Raptor 1 despite looking dramatically simpler, suggesting the complexity reduction came from engineering optimization, not compromise.
• The Raptor uses full-flow staged combustion, a notoriously difficult engine architecture that only SpaceX has successfully flown; the earlier versions routed propellant through more convoluted paths that later versions consolidated.
• SpaceX likely reduced engine complexity by combining the two preburners into a single unit and simplifying how fuel flows through the engine structure, based on comparison of fan-made schematics from Raptor 1 and later versions.