Thrustmaster added a new BOOST setting to their wheels in driver version 2021_TTRS_4. This setting only has an effect when playing on PC as it doesn't change anything on the wheels themselves. The release notes state that BOOST "improves on PC your performance by offering a more accurate feeling of the road." That's an extremely vague statement and doesn't tell us what this feature actually does or how it works.
When you enable the BOOST setting, it clearly makes the wheel heavier and forces stronger, but I certainly wouldn't say I was getting a "more accurate feeling of the road." From the description, I thought the BOOST feature would do some sort of dynamic amplification of weak forces, or other clever trick to provide more detail in the force feedback.
Since I wasn't noticing anything like that happening, I decided to test the feature with three Thrustmaster wheels and see exactly what is happening with and without BOOST.
Since every game has different force feedback, it would be difficult figure out exactly what BOOST is doing by subjective feel alone. Instead, I used the WheelCheck app to test the linear force response of the TMX, T248 and T300 when set to several different Strength values with BOOST turned on and off. I ran each test three times and averaged the results.
The following graphs are representative of every test I did. They have the Strength value set to the default for each wheel, with BOOST turned on and off. Note that the graphs are not scaled the same between wheels. The T300 is significantly more powerful than the other wheels.
Looking at these graphs, it is immediately obvious what the BOOST feature does. It simply multiplies the force by two, thereby doubling the rate at which the wheel reaches 100% force. When the game tells the wheel to output a 50% strength force, the wheel actually produces a 100% strength force. Any force over 50% that the game puts out is clipped, since the wheel is already at its maximum power.
What these graphs don't show is that the BOOST only raises the Constant and Spring forces. The Periodic and Damper forces are left alone. The Periodic signal is often used for vibrations, but it is entirely dependent on how a game implements its force feedback. In some games, the major forces would double with BOOST enabled, but the vibrations would stay the same.
Should You Use BOOST?
Having seen these graphs and from my own subjective testing, I do not recommend using the BOOST feature. I honestly can't think of a scenario where using BOOST would be useful or advantageous, since you lose all the force feedback information that is over 50% strength.
The only time where it would be useful is in a game that produced extremely weak force feedback. You could use BOOST to amplify the forces to a more reasonable level. I haven't found a game that has this problem, but I suppose some may exist.
I would be particularly worried using it with the TX and T300 since they are prone to overheating. Using BOOST would have those motors running twice as hard as usual, creating a lot more heat. I heard from one person whose T300 died a few weeks after enabling BOOST. It may have been a coincidence, but it's something to take seriously.
Individual Wheel Results
For those curious, I have included the full set of tests I did for each wheel. It's interesting to see that the T248 doesn't actually change the maximum force when you change the strength setting. Instead, it just changes the rate it takes to reach it. The others actually limit the maximum power available when you change the strength setting.
You can see that BOOST functions exactly the same no matter how the Strength value is set. It just doubles the power, squeezing the full range of power available to the wheel into just the 0-50% range.
I hoped the BOOST feature would do something much more interesting than just doubling the power. As it currently exists, its use is very limited. I like the direction Thrustmaster is going, though. Adding more features and options at the driver level has the potential to improve a lot of games that have very little customization when it comes to the force feedback.
I would be very interested if anyone has found a game that works well with the BOOST enabled. Feel free to let me know if you have any questions or comments.