The app takes exclusive control of the FFB sent to your wheelbase, which means that it is the only program sending force feedback to your wheelbase. This is required by DirectInput, and it is the reason why the app displays "Game FFB is blocked."

However, among the many telemetry channels that the App uses, lmuFFB includes a specific telemetry channel called "In-Game FFB", which allows you to still include the LMU original FFB signal within the final FFB that the app produces.

The "In-Game FFB" stream is the FFB produced by LMU. It is mostly based on the Steering Rack Torque (which is why in the app you can select it as one of the two possible steering torque sources), plus any additional effect and processing that LMU might be doing on it behind the scenes (eg. adding damping, smoothing, vibrotactile effects, etc.).

This stream is impacted by any setting that you might change from the game FFB Settings (see below).

You can control the impact of the In-Game FFB on the final FFB produced by lmuFFB in several ways:

• You can enable or disabled it: by selecting "In-Game FFB" as your Steer Torque Source in the app, it will be combined with all other telemetry-based forces processed by lmuFFB to produce the final FFB you feel.
• Game Settings: Any changes you make to LMU's internal FFB settings (strength, smoothing, vibrotactile effects, etc.) should directly affect what lmuFFB receives through this channel.
• In App Gain slider: The "In-Game FFB Gain" slider in lmuFFB acts as an additional multiplier to change the strenght of this specific channel.

In the App ("Front Grip" section), you have two options for your base steering torque ("Steer Torque Source"):

1. In-Game FFB:

   • Pros: High sample rate (400Hz), includes LMU's built-in processing (eg. smoothing) and specialized effects (eg. vibrotactile effects).
   • Cons: if you don't like the game built-in processing.

2. Shaft Torque (100Hz Legacy):

   • Pros: A "pure" source of steering rack torque information without game-side processing.
   • Cons: Lower sample rate (100Hz), potentially slightly higher latency (though usually unnoticeable), and may require gain adjustments via the "Steering Shaft Gain" slider, because it might have a very different baseline strength compared to In-Game FFB.