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The revolutionary new KS-4 is our most advanced knock detection system. Offering all the great functionality of the KS-3 but also a fully configurable 0-5v output and a remote alarm function allows the KS-4 to trigger a remote warning system.

The KS-4 contains all the great features of our KS-3 plus:

0-5v Analogue Data Out

The KS-4 contains a true 0-5v analogue data output. Data output rates are configurable at up to a blistering 100 samples per second and fully compatible with all datalogging software, Dyno's and ECU's.

External Trigger

The KS-4 external trigger function adds further flexibility by allowing you to power your own external warning devices when the KS-4 alarm is triggered.

Sensor Output

The signal from the sensor can be easily routed to another location within the vehicle. This can provide a more convenient location for the interface to the Knock Analyser Pro.

How does it work?

The KS-4 monitors engine knock levels and can be configured to alert the driver via a visual, audable or external warning device. The KS-4 can be used as a hand-held device or permanently mounted to the dashboard. The KS-4 is configurable for frequencies between 6 and 9 kHz. The system includes high quality Bosch Wideband Knock Sensor, Sensor Plug, Shielded Signal Cable, Mounting Kit and Wiring loom.


The KS-4 has been designed to be very quick to install. The KS-4 comes as a complete kit containing everything necessary for the installation. A high quality Bosch knock sensor is included and is linked to the main unit via a high quality shielded signal cable. Installation is very simple: Mount the sensor, connnect the signal cable and connect the power supply.

What is Knock?

Knocking or detonation occurs when unburnt fuel in the combustion chamber explodes instead of burning in a controlled manner. When engine knock is occuring the pressure in the combustion chamber rises dramatically to levels that can destroy engine components in a few seconds.

What does engine knock sound like?

See our video clips demonstrating our products in action clearly detecting engine knock. Towards the end of the demonstration there is an audio sample of knock.


The KS-4 is very simple to configure. The most common question we are asked is what frequency should I select. We now have an online calculator that will estimate the knock frequency for you. Use our Knock Calculator to estimate the knock frequency of your engine.

Phormula KS-4 Complete Knock Monitoring Kit