Custom Stainless Downpipe using RJC Flange

liquidh8

Active Member
Joined
May 17, 2006
I have a hybrid Buick/Olds/Pontiac G Body wagon. I decided to build my own downpipe, ensuring there are no clearance issues or things banging/hitting. I had a used SS Magnaflow exhaust system from a friends 04 Chevy 2500 from a few years ago, nice thick pipe and a lot of bends to choose from. I bought the SS flange with the giant puck from RJC racing. The car has new body mounts and already had the seam where the floor and firewall meet. I have a build thread of the frame off on gbody.

My TIG welding is a little rusty, so be nice.

Starting with a bend on the flange

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Test fit in place. Plenty of room for the AC box and the upper control arm. I will be using the stock control arm heat shield.
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Nice and tight to the engine.

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All welded up.

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Wrapped in DEI titanium wrap. This is really nice stuff, and super easy to get real tight!
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This leads to ceramic coated 3 inch exhaust. I just have to make the "test" pipe. I'll need a new flange and I will be using a SS flex joint in there. The exhaust hangers/mounts are SS with the little round poly bushings, so it is pretty solid. This is the reason I want to run the flex joint.
 
Thanks! I was just going to use a stainless band clamp like i did with the mufflers, but, the intermediate pipe still moves around with the clamp torqed down. So, I will be welding 3 bolt stainless flanges to the downpipe and test pipe.
 
Thanks! I was just going to use a stainless band clamp like i did with the mufflers, but, the intermediate pipe still moves around with the clamp torqed down. So, I will be welding 3 bolt stainless flanges to the downpipe and test pipe.


Ditch the downpipe wrap if that's 304 stainless
 
I appreciate the insight. I don't remember what grade stainless it is, but is was free, and only took a few hours to fab a DP that has absolutely zero clearance issues. If it lasts for a few years, I build another using the same RJC flange. :)
 
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