I received my AccessPort and was excited to give it a try.  I had been driving around with a very modestly modified 2005 STI including a full turboback exhaust, a K&N Typhoon Intake, and obsessive maintenance.  I knew that I was already driving something faster than stock, but I was eager to see how much of a difference some engine management would make.  The single biggest difference is in the boost control.  In the Stock ECM’s mapping, the turbo is not commanded to reach its full boost of 14.5psi until 4000rpm, with a gradual rise up to that point.  With the AccessPort, full boost is allowed nearly as fast as the turbo can produce it – which is to say, about 17psi at a thousand rpm sooner than the stock mapping allowed its 14.5psi.  This is where the biggest change in the torque curve is seen.  Beyond that, a smaller improvement is made over the entire remainder of the torque curve via boost, timing, and fuel improvements.  Using a popular Subaru data logging software suite known as DeltaDash, I measured these changes with back-to-back “Road Dyno” runs before and after the reflash to Cobb’s Stage2.  As you can see, there is a significant bump in the curve all the way to redline, with an iceberg of extra low-end torque.

My initial impressions were all good.  The car was definitely a fair amount stronger than before and it also was more willing to build boost faster.  As the days went by, and the ECM did a little bit of touch-up on the fine fuel trims and timing, the car got smoother and faster overall.

I was blown away by the fundamental change in my car the AccessPort reflash had made, but I wanted to see what this user tuning ability of the StreetTuner was all about, so after a couple days of enjoying the newfound power of my STi by destroying pretty much anything and everything that I encountered on the road, I decided to take the plunge and see what I could do with all this tuning power.