Go Fast Bits Whistling Trumpet Different Sound Kit Stealth FX and WRX Hybrid 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 issuewith 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 (Part numbers 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.
