Is it bad to hit the rev limiter when downshifting under hard braking?

Hitting the rev limiter when downshifting under hard braking is not inherently bad, but it depends on how it is done and the type of rev limiter your vehicle is equipped with.

Types of Rev Limiters

• Soft Rev Limiter: This type gradually reduces engine power by cutting fuel or ignition, which is less stressful on the engine components. It is more common in road cars and does not cause an abrupt halt in engine speed14.
• Hard Rev Limiter: This type cuts the fuel or ignition supply instantly, causing a more abrupt halt in engine speed. It is often used in track cars and can be more stressful on the engine if not managed properly14.

Downshifting and Rev Limiters

• When downshifting during hard braking, if you are using a hard rev limiter, it can create a 'bouncing' effect as the engine hits the rev limit and the limiter cuts in. This can be intense but is generally not harmful if the engine is properly maintained14.
• However, it is crucial to rev match when downshifting to avoid putting unnecessary stress on the clutch and other components. Proper rev matching ensures that the engine speed matches the gear you are shifting into, minimizing wear and tear3.

Best Practices

• Rev Matching: Always rev match your downshifts to ensure smooth transitions and minimal wear on the clutch and engine.
• Controlled Braking: Use a combination of engine braking and traditional braking to control your speed. Engine braking can help in managing speed before applying the brakes, but it should be done smoothly and not aggressively35.

In summary, hitting the rev limiter while downshifting under hard braking is not necessarily bad if done correctly with proper rev matching and control over the braking process. However, it is important to be aware of the type of rev limiter your vehicle has and to manage the downshifts accordingly to avoid unnecessary stress on the engine and other components.