You asked, we delivered!
Many times we have been asked for a replacement trumpet that gives a different sound, and here it is.
The ability to change the sound of a Blow-Off Valve is increasingly becoming an important issue with buyers, who want to sound different from everyone else.
In 2004, the Whistling Trumpet was released which emitted a piercing screech when driving aggressively.
The 5701 can be used in place of the standard trumpet on GFB valves T9003 & T9503, and will make a whistling sound. However, it is necessary to run the valve so that all (or most) of the air vents through the trumpet. Respons valves will typically not generate the velocity required to whistle when set to 50/50 venting.