Hard Cut – Rev Limiter Solution


Hard Cut Limiter cuts fuel at the set RPM limit. This changes how the engine behaves and changes the sound of the vehicle at the RPM limit. With the manufactures RPM limit, a diesel car will hit the limit and will stay at the exact point until the driver takes his foot off the gas pedal. Quantum Tuning Motorsport rev limiter allows to reach the actual engine speed limiter without prelimiting the engine power output first. This way all the engine power stays available which allows better acceleration and a true motorsport experience within legal limitations.

Hard cut rev limiter can be achieved with ECU remapping. A rev limiter is a device that prevents the engine from revving too high. It does this by cutting off the fuel supply to the engine when the RPM reaches a certain point.

The soft cut rev limiter gradually reduces the fuel supply as the RPM approaches the limiter. This results in a smoother transition from the maximum RPM to the limiter. The hard cut rev limiter cuts off the fuel supply instantaneously when the RPM reaches the limiter. This results in a sudden drop in power and RPM.

Hard Cut Rev Limiter with ECU Remapping

  1. ECU Remapping: To implement a hard cut rev limiter, the vehicle’s ECU is reprogrammed or remapped. The ECU is adjusted to include the hard cut feature and set the desired RPM limit at which it will engage.
  2. RPM Limit Setup: The hard cut rev limiter is programmed to activate at a specific RPM level chosen by the vehicle owner or tuner. This is often set slightly below the engine’s redline to provide a safety margin.
  3. Cutting Fuel or Ignition: When the engine reaches the set RPM limit, the hard cut rev limiter intervenes by either cutting off fuel delivery or ignition spark. This sudden interruption in power causes the engine to momentarily lose power and prevents it from exceeding the designated RPM limit.
  4. Recovery: After the engine drops below the RPM limit (usually due to a downshift or lifting off the throttle), normal operation is restored, and the engine continues running as usual.

Benefits for Hard Cut Rev Limiter with ECU Remapping

  • Enhanced Control: A hard cut rev limiter provides precise control over the engine’s RPM limit, preventing unintentional over-revving that could lead to engine damage.
  • Performance and Tuning: In certain performance applications, tuners and enthusiasts may use a hard cut rev limiter to create dramatic sound effects, such as backfires and pops, during gear changes or deceleration. This can enhance the auditory experience of driving.
  • Safety: While hard cut rev limiters are often associated with performance and racing, they can also serve as a safety feature to protect the engine from unintentional over-revving.

If you are considering a hard cut rev limiter with ECU remapping, it is important to weigh the risks and benefits carefully. It is also important to choose the Certified Quantum Tuning Dealer who has experience with this type of modification.

Things you should Consider

  • Engine Durability: Although hard cut rev limiters can add dramatic effects to the exhaust note, they can also place additional stress on engine components. Regular maintenance and monitoring are essential.
  • Noise and Emissions: The abrupt cutoff of fuel or ignition can lead to loud exhaust pops and potentially increased emissions. This can impact street legality and local noise ordinances.
  • Professional Tuning: Proper implementation of a hard cut rev limiter should be performed by Quantum Tuning Certified Dealers who understand the specific needs and limitations of your vehicle.

We tune over 4000 vehicles a month with 1000+ approved dealers in 90+ different countries. Don’t have a ecu tuning tool? We can supply the latest ecu remapping tools, at great prices, from the market leaders. They are available in slave or master versions.

Quantum Tuning offers the solution by overwriting the existing settings within legal limitations of a vehicle’s Engine Control Unit (ECU) to improve several areas of the vehicle’s performance. This is not legal advice and if you are unsure if this applies to your vehicle, please seek further advice.

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