Project SR E30: Part 8 – Fabricating a Custom Stainless Steel Oval Exhaust
Tig welding stainless steel exhaust pipe
With the pipe back purged, we can finally start welding!
Back purged stainless steel pipe inside
For reference, this is what the inside of a back purged stainless steel pipe is supposed to look like after welding. This is from a test piece I did earlier. Notice how there is zero sugaring or porosity.
BMW E30 SR20DET swap downpipe clearance
We test fit the downpipe after welding and noticed that it was touching the lollipop bushing.
Hammering a downpipe for clearance
We gave the downpipe a stern talking to.
BMW E30 SR20DET downpipe bushing clearance after hammering
It just barely clears the bushing now. We may switch to an adjustable spherical bushing, later on, to gain more clearance if we have issues with burning up the polyurethane.


    1. At the time, we couldn’t find any decent oval exhaust flanges that wouldn’t have taken away from the ground clearance.

      That being said, the exhaust is actually pretty easy to remove.

  1. Nice work, I was gonna see if you can check out the treehouse racing lollypops. they are smaller in physical size and gain more clearance. Your build reminds me of one of my friends who went KA-t in an e30 and it ran pretty gnar.

    Tip: might want to 2-piece the exhaust for when you need to change out the guibo, subframe bushings, and other rear maintenance.

    1. Yeah we’re definitely going to switch to a heim-style lolipop bushing down the line. I’ve gotten that burning polyurethane smell a couple of times already.

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