I was thinking about the HKS universal sequential blow off valve. what gains will you get what are the cons about it??<p><br>I have been thinking about this for a while??? the Japanese guys use it alot but what does it do besides just making that cool hissing sound?

I happened to read about blow off valves on Hoppen Motorsports page. Try this link:<p>http://www.hoppenmotorsport.com/serv01.htm<br>

<br>A blowoff valve relieves pressure in the intake system when the throttle plate is closed. This air that is stuck in the system, stalls the turbo causing lag between shifts. When it senses the vacuum, it blows air out. However, a sequential type blow off valve like HKS's is atmospheric, which mean sit blows this air into the atmosphere(hence the cool sound). Audi's though, which use mass air-sensors need to have the air re-routed back into the system like the stock set-up. changing to a HKS valve probably wouldnt work correctly, and besided the gains if any, will be minimal. follow the link provided by the other response, i explained the difference between the type of valves used.

You are right for the most part, however I think the primary response is not only to reduce turbo response, but rather prevent compressor surge (air being pushed back, forcing the the compressor wheel to spin the opposite direction.)<p>The HKS may not fit, but the GReddy does possess the capability to re-route back into the intake.