Our friend Rennie at Redline BMW came through for us with a replacement downpipe, so we were able to finish up the Spec E30 exhaust install this weekend. The trickiest part of the operation was fitting the two downpipe tubes into the Spec E30 exhaust’s flanges. In a nutshell, we figured out where to cut the tubes, used a fiberglass cutting wheel to slice through the metal without deforming it, Dremeled away some material from the outer edge to make fitment easier, and then slid the downpipe tubes into the exhaust flanges with a dash of good ol’ 5W30 motor oil to facilitate things.
Once we had the BMW downpipe securely fastened to the first of the three parts of the Spec E30 exhaust, we mocked up the fit and then took the pipe assembly over to Per so he could weld in an O2 bung for our upcoming Innovate Motorsports air/fuel monitor installation.
Bolting the downpipe to the exhaust headers is a bit of a pain; we used plenty of weird extensions, angle drivers, air-driven impact wrenches and manual gear wrenches in the process. The middle and rear segments slipped together with ease by comparison. Ours is a very early version of the exhaust, so it only had one rear hanger for the rubber doughnuts in the back. Apparently the newer versions use dual hangers and forgo the middle-section hanger, so we might weld on a bar of steel to mimic the newer style.
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