For the exhaust I wanted it to look nice, sound great but not be too loud and easily support 300 whp. The ehxaust is 3" from the downpipe back passing through a Carsound high flow catalytic converter and ending with a SS Magnaflow muffler. The tip is just polished 3" 304SS pipe TIG welded on. The hanger was bent out of 1/4 solid stainless rod.
I can say that now that the car it running is has met all of my expectations. It sounds great but isn't too loud and doesn't drone.
Now that the turbo was mounted up, it was necessary to plumb an oil feed and an oil return system. You don't want to skimp here as if you have any leaks, you risk pumping out your engines lifeblood and destroying a turbo or even your engine.
For the supply I started with Russell braided SS -4AN line and used some very nice billet inlet and drain adapters from Function7. I drilled and tapped the oil filter housing 1/8" NPT for my supply line. For the return, I drilled and tapped my oilpan for a 1/2" NPT fitting. I used very high quality 316 stainless Swagelok tubing and connections mated to their teflon lined braided hose to feed back into the pan. It wasn't cheap, but it should never leak. Here you can also see the placement of the external wasgate which tucks up nicely near the engine mount and plumbs the exhaust back into the downpipe.
I think all turbo cars need to be intercooled. Most e28 turbo kits use water to air intercoolers due to the limited amount of space behind the front bumper. Since I had no problems with cutting into the sheetmetal of my car, I decided to go with a front mounted air to air intercooler which was purchased off of ebay. The core is decently sized and fits nicely behind the factory airdam with minor trimming giving a very clean, stealthy appearance.
I purchased an 2.5" intercooler pipe and connector kit off of ebay which supplied more than enough bends to carefully route the piping through the engine bay. I did have to cut one 3" hole in the passenger's fenderwell to route the compressor outlet to the inlet of the intercooler. The IC piping is connected to the throttle body with a 2.5" to 3" elbowYou al see the inlet to the turbo as well as the billet Bosch style bypass valve to prevent compressor surge. The turbine housing was also wrapped with a DEI turbine blanket to reduce temps under the hood.