This was quite the project. I've never build an exhaust system before so the challenge was a steep one.

A quick note: Why didn't I just run a “Y pipe” and run a single pipe all the way back. Yes it would be easier, cheaper, and more compact. Ill counter your question with another - Why are there no performance exhausts for sale for any I6 or v8 BMW that utilize a single pipe? The answer (in my opinion) Is that #1, I6 motors sound like POOP with a single pipe, like, really bad. #2 There is also the efficiency of the motor to take into consideration. Clearly BMW as designed and the aftermarket has maintained that two pipes are better than one for performance. So why mess it up?

Rant over on that front, on to the fun stuff

Here's my pile of pre-ordered guess at what I would need to make this a reality. Summitracing.com and siliconintakes.com were my vendors of choice… along with a few random ebay add ons in there (v-bands). 100% stainless including the mig wire used to weld everything, and boy is that fun to deal with - as you can tell by my crappy welds.

Didnt end up using the x-pipe.. still considering adding it later though. 

The first and possibly most annoying task was to make two flanges that mate up to the stock manifolds I'll be using. For this task I sources some ⅜” thick stainless plate from our local metal supplier. I proceeded to use a stock exhaust gasket as a template for what i was creating. After about 4 hours and a lot of cussing I had my flanges. This task would have been impossible without a mill that could turn as slow as 80 RPM.

After the flanges were done, I started the process of building the downpipes. I've had issues in the past with long tube headers snapping off at the collector, so I added a small flex pipe to each tube in that area to help everything be happy. Added a mount to the trans bracket after notching it ( this will be changed slightly, i'll mount a longer rod across the bottom instead of meeting it against the tube, before the final product is done). Then added a v-band for each pipe just past the trans, staggered for ease of removal, and clearance .

Ran the two pipes up into the tunnel and back and over the axle on both sides, adding another v-band on each side before the turn down to get below the cv axles, again for easy removal.

Now since this is (was) a tii, the stock external fuel pump hangs out right where I ran the over axle pipe on the passenger side, so that will need to be relocated/replaced when its back on the lift next.

At this point it was time to figure out what and where my mufflers and tips were going to be doing in this set up. My boss recommended connecting the mufflers as an assembly with some strapping, then connecting the tips how I wanted them, then connecting the pipes from the car to the muffler/tip combo. So I did! This ended up being quite a complex project, but I eventually figured it out. I also needed to finally cut the rear valance in the center for the dual tips. Funny since Ive had a center exit exhaust on this car since Ive owned it. I also closed up the right side stock exit hole.

Although, I knew this wouldn't fit with the spare tire well. So I did what I’ve been meaning to do for years anyway and cut the damn rusty thing out! After that there was PLENTY of room for mufflers! No problem. Now all I had to do was connect the dots. Bing bang boom. Dual exhausts. The downer part about this is I have no idea how it sounds because I had already taken all my other work apart to sand/prime the engine bay to send it to paint as soon as this was done. All to more to look forward too! This car is probably going to be pretty damn loud.

Here are the three sections removed so the car can go to paint, and I can finish welding a few tubes that are still just tacked. Will still need to make some hangers for the rear but that shouldnt be too hard.