Yet Another Happy Treadstone Performance Engineering Customer! "Treadstone Stage 4 Kit. Anybody that has ever even heard of Treadstone knows that they make high quality part, and that is still true for this kit. This kit comes with everything you need to turn your 08-10 Cobalt SS into an even more enjoyable car. For starters, and in my opinion the best piece, is the turbo manifold. Its new "out of the box" styling has made it a standout manifold in the Cobalt world. Much better appearing that the typical log-style manifolds. And being that it is a cast tubular design, it also has the performance side of the board covered. Its a thing of beauty, in and out. I honestly didn't want to put it on the car. I would have rather made it a center piece for my dinner table or something! Mated with Treadstone's own TR series of intercoolers (TR8 in my case) as well as their flat textured black intercooler piping and intake pipes, the kit leaves your engine bay looking stealthy yet aggressive. People will know you aren't messing around when your hood is popped. This kit also has many turbo options available to boost your power up to pretty much as high as you want. Me personally, I went with the Precision 5557 with the billet wheel and .63 a/r. For me this was a perfect choice for this car as it doesn't have crazy amounts of turbo lag yet still is able to produce 500hp. My daily driver tune was a 91 oct, low timing and set at 24psi and I was able to achieve 407hp at the wheels. In combination with Turbosmart for the blowoff valve and wastegate, this kit has the looks to kill and the proven performance to shock just about anybody with your Cobalt SS. There is nothing bad to say about this kit and if you are in the market for an aftermarket turbo kit, feel confident that you will be satisfied by choosing Treadstone, just as I am." [gallery] Click Here For More Info!