Tuesday, August 9, 2011
I recently installed a Billy & Boat (B&B) aftermarket downpipe on the STi. I purchased it used from a friend at an amazing price. It is a catless pipe which is not what I wanted to go with but it was to good of a deal to pass up. Before installing I order new gaskets for the front and rear of the pipe. I went with Grimmspeed's thicker gaskets as well as the 3">2.5" adapter to ensure a good fit. Since this pipe has no heat shielding (like the stock one does) I ordered some DEI high temp exhaust wrap for the front half of the pipe to keep the heat out of the engine bay. I also picked up some of the hi temp silicone spray paint that they make to seal up the whole thing. I followed this DIY thread on changing the down pipe and this DIY thread on trimming the turbo heat shield to fit the new pipe. The heat shield thread was written for a bell mouth design downpipe but it work perfectly for my divorced waste gate setup as well. Once I was done I used my Access Port to flash the correct stage 2 map onto the ECU and I have been enjoying the newly found power and sound ever since!