Reality Expansion Pack: The most realistic X-Plane engine ever

Advanced Engine Simulation

The Reality Expansion Pack (REP) introduces the most sophisticated piston engine simulation in X-Plane, built from the ground up. This fully custom engine model completely replaces X-Plane’s default engine dynamics, delivering a highly realistic experience across all REP-supported aircraft.

Why a custom model? It enables detailed simulation of each component you’d find in a real piston engine. REP’s code meticulously recreates the behavior of pistons, cylinders, oil flow, fuel lines, injectors or carburetors (depending on fuel metering type), the battery, cowl flaps, spark plugs, and every other detail that brings an engine to life.

This realism means you must manage the engine carefully. Follow proper procedures for starting, warming up, and operating the engine in-flight—otherwise, it may fail when you need it most.

Just as with a real aircraft, the engine wears down with each flight. Neglect essential maintenance, like timely oil changes, and the engine may eventually fail.

With each update, REP’s engine logic grows even more detailed, adding new aspects to monitor and learn as you fly.

Engine Upgrades

Thanks to REP’s custom engine model, you can even simulate real aftermarket modifications, like tuned exhausts for increased power or balanced fuel injectors for improved fuel efficiency.

The Features

Here’s a list of features that REP can realistically simulate within X-Plane:

1. Proper procedures for pre-heating, priming, and startup
2. Realistic engine spool-up and “roar” at startup
3. Starter overheat and wear
4. Turbocharger with automatic waste gate
5. Turbocharger with fixed waste gate
6. Turbo lag
7. Realistic engine torque
8. Correct EGT behavior
9. Perfectly matching power output (BHP) at every regime/setting
10. LOP and ROP operations
11. Spark plugs fouling
12. Interchangeable spark plugs between default and fine-wire
13. Switch between default and balanced fuel-injectors
14. Switch between default and tuned exhausts
15. Correct cowl flaps drag
16. Realistic engine vibrations (needs HeadShake)
17. Cylinders compression
18. Cylinders cracking and seizure caused by improper engine management, such as running at high RPMs when the CHT is still too low
19. Propeller movements at low speed caused by the cylinders compression
20. Fuel filter clogging
21. Fuel vapor in the fuel lines that may prevent a startup
22. The “popping” and “spitting” sounds of a big bore engine
23. Oil viscosity at different temperatures
24. Different oil types (SAE10W30, SAE30, SAE50) that can be replaced in the hangar
25. Oil filter clogging
26. Oil fluid quality reduction
27. Oil pump failures
28. Vacuum pumps failures
29. Electric pre-heating
30. Winterization kit

Engine Behavior

Did you know X-Plane’s default piston engine model isn’t fully optimized for simulating specific engines? It’s designed to work with a wide variety of aircraft, which means it relies on compromises to deliver performance that’s “good enough” in most situations, but not tailored for true realism.

This is where the Reality Expansion Pack (REP) changes the game.

Each engine modeled by REP is meticulously crafted to exhibit realistic, unique behavior, setting it apart from X-Plane’s default engine model. REP engines can suffer from fuel vapor starvation or flooding if not handled properly, requiring careful management just as a real engine would.

These engines deliver accurate horsepower at any throttle setting, with fuel consumption and thrust precisely tuned for all operating conditions. Additionally, you must correctly prime the engine before startup, considering cylinder temperature—just like in real-world aviation.