Leaks like a Siv? Haha I don't think you know what you are talking about. Whats up Bucs.. This is AnT that was out in my friends Aaron's black Z31 a few weeks ago. It is a pretty good blow off valve. They come standard and then another rated at 25 psi boost level. You just have to choose which one you want for your application and then it all comes down to choosing by the type of sound you want. (which blow off valve) I never really heard negative about any blow off valves besides people buying used ones or know nothing about them. Some leak due to the fact that some have an adjustment on them etc. Aaron has one on his z31 and never had any problem with them and I have another friend with dual's on his TT. I have the Greddy Type -S which as well I never had any problems. You can PM if you want. A friend of mine owns a machine shop and can make anything you want or help you with the blow off valve and whatever else you need. He also has an Mk3 with many other Supra friends =-)