Well today went to Go Fast Bits in Sydney to help Brett Turner one of the engineers with the design and installation method for a blow off valve for the XR6 Turbo. The main issue with installing the blow off valve on the XR6 Turbo is mainly due to room. Their is not enough room to fit it in properly. Working with another vendor a few weeks back we looked at cutting the left hand side rubber piping and making a custom bracket to hold the blow off valve. This proved to be a good idea at the time, but after checking with Ford spare parts the rubber piping was roughly $400 to replace, as the only way to buy it was in kit form which included the black "Turbo" housing. I contacted Go Fast Bits out of curiosity. Junior (rjs) a member on our site mentioned that they had developed a unit called the Stealth FX. This unit basically is a custom designed and patented blow off valve which unlike others on the market is fully adjustable, it lets you set the volume of the blow off valve similar to a car stereo, of 1 to 10 with a quick turn of the BOV. 10 of course is the loudest, and yes its very noticeable. Or you can move it to the 1 position which returns it to the same sound level as the standard bosch one. Installation was a breeze, basically taking off the plastic Turbo Housing to reveal the Bosch valve, undoing the Bosch valve by leavering off the fasteners, and plugging the Stealth FX into the existing rubber hosing. I was quite amazed that it fit so easily and so snug compared to the other manufacturer i had a look at a few weeks back. The good thing about the ease of installation is not only that you can get your hands in to adjust the BOV for noise to make it silent, but it can easily be removed without causing any hassles at all. I was really impressed with the quality of the blow off valve from GFB and the design of it. Alot of thought has gone into the engineering of the product and it certainly shows. Another good thing about it as discussed in other threads, that the venting of air could be seen as bad in some cases. A quick turn of the ratchet style head redirects the air to the inlet, instead of venting it to the atmosphere. More info on the Stealth FX can be found here: http://www.gofastbits.com.au/stealth.htm Im not an expert at BOV's or Turbo's and dont claim to be. But from driving it around today and this evening. I have not noticed any changes in performance and the like. (I still have the old bosch one and can easily put it back in anytime if i do). The RRP on the Stealth FX Valve is $530 and can be purchased by contacting GFB at sales@gofastbits.com.au or by calling them on 1300 767 666 Dont forget to mention the site FordXR6Turbo.com when you call or email. They will do their utmost to help.