Whistling Trumpet Sound Upgrade for GFB Blow-Off Valves

The GFB Whistling Trumpet was developed in response to repeated requests for a blow-off valve trumpet that produces a noticeably different sound. As sound customisation has become increasingly important, GFB introduced this design to deliver a sharp, high-pitched whistle when driven hard.

Distinctive Whistling Sound

First released in 2004, the Whistling Trumpet emits a piercing screech during aggressive driving, giving the blow-off valve a unique and recognisable sound signature.

Installation and Operation

The 5701 Whistling Trumpet can be installed in place of the standard trumpet on compatible GFB blow-off valves. To achieve the whistling effect, the valve must be configured so that all or most of the discharged air is vented through the trumpet.

Venting Configuration Considerations

Valves configured for partial recirculation, such as Respons valves set to 50/50 venting, typically do not generate sufficient airflow velocity to produce the whistling sound.