First introduced with Update 2.0 on selected car classes, and then further expanded with Update 2.0.0.2, Project Motor Racing took a significant step forward in how throttle response and engine behaviour are simulated. This isn’t just a technical improvement; it’s a fundamental shift in how the car communicates with the driver.

To achieve this, we analysed real-world data measuring how engines produce torque and power relative to throttle input. From that, we developed an approximation model that closely matches these behaviours across the full RPM range.

Real engines are inherently non-linear. At partial throttle, power delivery does not scale directly with input, and this behaviour changes depending on RPM. Previously, engines could continue to rev towards redline even under light throttle — something that does not reflect real-world behaviour.

Real-world throttle vs power curve—note the non-linear relationship between input and output.

The updated system introduces a more accurate mapping between throttle input and torque output. This allows for sharper response at lower RPM and a more progressive, controlled delivery as revs rise.

Old throttle response. Our old system gave something like this when tested at around 60% rpm.

New throttle response: changes with starting RPM.

With update 2.0, we got more like this. You can see that 50% throttle output already gives you over 70% of the power you're going to get at that specific rpm. At higher RPM it gets somewhat more towards linear, but overall, you tend to get more percentage of power than percentage of throttle still. This all means that as you step on the throttle, you get power earlier, sharper, through the travel.

This system moves beyond a one-size-fits-all model. Each engine can now express its own mechanical identity, from the lazy throttle behaviour of the BMW 320 Turbo Group 5 small inline 4 engine with a turbo bigger than a house, to the instant reactions of the naturally aspirated rotary engine of the Mazda RX-7 GTO and the modern delivery of a car in the GT500 EVO class.

Turbo response example: How torque and power grow as the turbo spools up, compared to steady state.

Throttle response example: how power builds progressively with throttle input.

This graph shows how throttle response changes with starting RPM. The orange line is at 2500 rpm, and you can see that 25% throttle already gives almost 60% of the total power available at that low RPM. At higher RPM, the behaviour trends somewhat closer to linear, but overall, the engine still tends to deliver a greater percentage of power than the percentage of throttle input. In practice, this means that when you step on the throttle, power arrives earlier and more sharply through the pedal travel. The high RPM results go below the 0% power line because of curve smoothing on the graph but also tell you that you'd be getting engine braking at low throttle and high rpm.

On track, this translates into stronger response at lower RPM, a more intuitive connection between throttle and acceleration, and greater control when managing traction. It becomes easier to balance the car, particularly on corner exit.

Try It Yourself

Even when stationary, the difference is clear. Rev the engine and notice how quickly it responds and how precisely you can now hold a specific RPM. That same control carries directly into driving situations.

The following classes now have this new throttle response model implemented in all their respective cars.

• Group C

• GTO

• GROUP 5

• GT500

• GT500 EVO

• N-GT

• Porsche 992 Trophy

• AUS-V8 — Ford Falcon V8

Future updates will bring this throttle response model into other cars.

This new throttle model is part of a broader effort in Update 2.0 to improve clarity and communication between car and driver. As we continue refining each class, this system allows us to better express the unique behaviour of every vehicle.

This is the beginning of a more expressive simulation, where every car doesn’t just perform differently but feels different.

Every racing season has a moment where the grid resets, lessons are learned, and the next phase begins.

For us at Straight4 Studios, Update 2.0 is that moment for Project Motor Racing.

Since launch, the team has spent months refining the experience alongside the community. Player feedback, internal testing, and a lot of iteration have helped shape the path to Update 2.0 which represents a substantial milestone that touches almost every layer of the sim — how it looks, how it feels to drive, how it works online, and how players progress through a racing career.

In short, this update sets a new baseline for Project Motor Racing moving forward.

Some of the highlights include:

• A clearer and faster User Interface (UI)

• Anti-cheat system for online modes.

• Reworked Career Mode.

• Refined driving physics.

• New tyre mode across multiple car classes.

• New HUD toll: the ECU Widget

• Improved visuals and performance.

Update 2.0 marks an important milestone for Project Motor Racing, but it’s not anywhere near the final destination.

Moving forward, our focus remains the same: continue developing the sim alongside the community and keep improving the experience with every update, and, in addition, work continues in bringing much-desired components to the sim — we're always listening and taking note of community feedback.

To everyone who has been part of that journey so far — Thank you. You are guiding us to be better.

And for those looking for the right moment to step onto the grid, Update 2.0 is a great place to start.
For a quick overview, watch our Update 2.0 Launch Trailer.

For a full breakdown read the patch notes.

We’ll see you on the grid.