With the removable extended trumpet, you can configure the T9401 to give you either a classic “whoosh”, or the loudest, most unique whistle sound you’ve ever heard on a Euro vehicle!
The T9401 also features adjustable spring pre-load so you can fine tune when it blows off, and for how long. A softer pre-load allows the valve to blow off for longer and at lower engine loads. If you prefer to hear it only at higher engine loads you can use a firmer pre-load.
Using our integrated solenoid design stacked in an “over/under” configuration, the super-low profile allows clean and simple fitment (even if your aftermarket intake is using up all the space!)