flex section for the wastegate!? talk about overdoing it.
How does a 2.5 run right out of the passengers side fender sound? Smoke the ricer in more ways than one.
Thats the plan for me. SS tubings and bends are easily bought from truck supply houses.
Well, I'm trying to avoid too much sound

Silent death is more fun for me!
About the second flex pipe, hey, that's absolutely necessery! Every time you see a twin-downpipe design, the W/G downpipe always needs to have a flex pipe of some sort before it's connected back onto the primary downpipe.
You need it because when the primary downpipe sees somewhat constant temperatures during driving, the secondary downpipe becomes hot very rapidly every time the waste gate opens, and after that quickly cools down again. You can see what would happen were it not for the second flex pipe!
I guess I dont mind mine being loud....
the Tial 38mm wastegate is gonna be vented to atmosphere.
I'm putting a 1.6 turbo diesel in my 1966 Volvo wagon along with an Isuzu truck intercooler. This looks like a great setup. I have the same manifold that you started with and I was wondering what it was like to weld the components together. I had just about decided to go with a fully fabricated intake as well as exhaust. I was worried about the different grades of aluminum between the cast manifold and the tubing. I also remember cast aluminum being porous and holding oil residue that can mess up a nice weld. What was the source of your aluminum tubing? I was wondering also why you went with such a large diameter on the exhaust tubing. I was thinking of using something about 1.5" in diameter for my exhaust manifold. What size and style of turbo are you using? The photos are great. Do you have more to post?
I got my system from Techtonics and it's great. it's 2.25 in. and I wouldn't go any bigger. just my 2 cents.
Ive read this tread and read about a few members having difficulty getting tube/ bends etc.
I collect truck exhaust systems 2/2.25/2.5/3 inch sections or lengths and cut em up for my 'system'...
I wear out my face a bit at the local 'truck centre', but i wouldnt dream of paying for bends etc... it increases the 'selection' of bends at hand etc...
naturally I'll proberly be told this is all wrong for some reason... but I cant see the difference....