Custom manifold, downpipe, and exhaust build
#1
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Thought I would throw up some sequential pictures of the turbo setup I just finished and installed about a week ago. I used hf-mx5t's manifold as inspiration, because I wanted it to be a short tubular manifold with the same turbo mounting position as my previous manifold (low mount). I made a jig from the previous manifold to hold the two flanges in place so that I could work on the manifold without the car.
It is completely tig welded, and I used mcmaster carr steel 1 1/2 inch bends to make the manifold, some short radius, some long radius. I had the manifold ceramic coated afterward.
The downpipe and exhaust is full three inch all the way, steel also. Next setup will be all stainless.
I started by making the manifold out of toilet paper rolls to help me visualize the whole thing and see how it would go together.
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Next I made the front and back halves separately, so I would only have to deal with the collector two pieces at a time.
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Then I cut each half to fit them together, and welded the manifold up.
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Then I sandblasted the whole thing and drilled the hole for the watesgate and welded the flange on. I bought the wastegate used, and i thought i should machine out a slot for the little protruding ring to fit into, can you guys see that? In hindsight i think that flange is supposed to be flat to push the ring up to seal. I had to put a gasket on the flange into the wastegate to make it seal.
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Done picture, and one with air box and filter back on, my favorite.
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Downpipe all tacked together ready for welding. I still need to put a flex tube into the wastegate part, anyone know where i can find a 1.5 inch flex tube? I couldn't find one from a place I trusted online.
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Exhaust pieces, a picture of how close it was to make the 22 inch magnaflow fit, a final exhaust picture, and a v band weld. The muffler was completely worth the hassle of fitting it in there.
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Overall, I love it, it spools way faster than my old log mani, internal wastegate, and 2.5 inch exhaust.
It is completely tig welded, and I used mcmaster carr steel 1 1/2 inch bends to make the manifold, some short radius, some long radius. I had the manifold ceramic coated afterward.
The downpipe and exhaust is full three inch all the way, steel also. Next setup will be all stainless.
I started by making the manifold out of toilet paper rolls to help me visualize the whole thing and see how it would go together.
![Name: IMG_0510.jpg
Views: 659
Size: 106.7 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190467d1501222699-custom-manifold-downpipe-exhaust-build-img_0510.jpg)
![Name: IMG_0511.jpg
Views: 802
Size: 120.7 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190468d1501222699-custom-manifold-downpipe-exhaust-build-img_0511.jpg)
Next I made the front and back halves separately, so I would only have to deal with the collector two pieces at a time.
![Name: IMG_0590.jpg
Views: 725
Size: 166.5 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190469d1501222699-custom-manifold-downpipe-exhaust-build-img_0590.jpg)
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Size: 181.8 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190470d1501222699-custom-manifold-downpipe-exhaust-build-img_0593.jpg)
Then I cut each half to fit them together, and welded the manifold up.
![Name: IMG_0618.jpg
Views: 671
Size: 131.1 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190471d1501222699-custom-manifold-downpipe-exhaust-build-img_0618.jpg)
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Size: 88.4 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190472d1501222699-custom-manifold-downpipe-exhaust-build-img_0630.jpg)
Then I sandblasted the whole thing and drilled the hole for the watesgate and welded the flange on. I bought the wastegate used, and i thought i should machine out a slot for the little protruding ring to fit into, can you guys see that? In hindsight i think that flange is supposed to be flat to push the ring up to seal. I had to put a gasket on the flange into the wastegate to make it seal.
![Name: IMG_0639.jpg
Views: 651
Size: 137.2 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190473d1501222699-custom-manifold-downpipe-exhaust-build-img_0639.jpg)
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Done picture, and one with air box and filter back on, my favorite.
![Name: IMG_0684.jpg
Views: 682
Size: 195.5 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190475d1501222699-custom-manifold-downpipe-exhaust-build-img_0684.jpg)
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Downpipe all tacked together ready for welding. I still need to put a flex tube into the wastegate part, anyone know where i can find a 1.5 inch flex tube? I couldn't find one from a place I trusted online.
![Name: IMG_0696.jpg
Views: 745
Size: 108.8 KB](https://www.miataturbo.net/attachments/diy-turbo-discussion-14/190477d1501222699-custom-manifold-downpipe-exhaust-build-img_0696.jpg)
Exhaust pieces, a picture of how close it was to make the 22 inch magnaflow fit, a final exhaust picture, and a v band weld. The muffler was completely worth the hassle of fitting it in there.
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Views: 641
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Overall, I love it, it spools way faster than my old log mani, internal wastegate, and 2.5 inch exhaust.
#9
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Thanks for all the compliments guys.
Jason I'd love to help out, pm me when the time comes. You have a place to do it? We can use my garage if not, it's doable to make a whole exhaust in a day.
Shlammed- I would, but the v band is too far down by the diff that the other parts of the exhaust would hit stuff if rotated. I would have to add another vband and change the hangers a little bit, I will probably do this when I do the rest of the changes late march. ( adding flex to wastegate tube)
Jason I'd love to help out, pm me when the time comes. You have a place to do it? We can use my garage if not, it's doable to make a whole exhaust in a day.
Shlammed- I would, but the v band is too far down by the diff that the other parts of the exhaust would hit stuff if rotated. I would have to add another vband and change the hangers a little bit, I will probably do this when I do the rest of the changes late march. ( adding flex to wastegate tube)
#17
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Since that build, I've built two more exhaust systems with the same muffler, both times I welded the hangers to end caps and made the entrance to the muffler shorter. Every new setup i learn something new
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