I dont know much about blowoff valves just their main purpose. I noticed on imports when they just rev the motor it will blow off just as they were driving. I have to be driving to blow it off. Why is this? I heard a sound clip of one guys Sy with a Turbo XS RFL just reving and blowing off. Is it a certain way hook it up or am I just crazy. Thanks for any help. Sorry if the answer was in another post.