Exhaust swap - fabrication of downpipe to transaxle bracket

[Agnelli]

128 wagon came with a 4-1 manifold in to 2" muffler shop exhaust. Prior owner's mechanic @ Wine Country Motors swapped out the 4-2 manifold and downpipe due to repeated gasket failure at the manifold exit to downpipe entry.

Project here is to revert to 4-2 stock 1974 manifold (now installed), Supersprint exhaust center section, an Ansa rear / resonator. All that came in the parts stash with the car. But the one key missing element is the aforementioned bracket. Unobtanium. An opportunity to improve the stability of that gasket point.

Sourced really nice 1" mild steel box tubing from eBay.

Highly recommend the eBay source: Leoni Steel in SoCal. Very nice material. Drilled, Dremeled, Sawzalled after a cardboard template. The stock bracket is flat, hoping this boxed solution will aid in securing the downpipe from exhaust system flexing.

 

[carl]

Where does the bracket attach to, I hope not the chassis.

 

[Jeff Stich]

Prior owner's mechanic @ Wine Country Motors swapped out the 4-2 manifold and downpipe due to repeated gasket failure at the manifold exit to downpipe entry.

Check to make sure you don't have a '74 X1/9 exhaust manifold (instead of a '74 128 manifold). This will cause constant issues at this gasket joint due to system misalignment (btdt).

But the one key missing element is the aforementioned bracket. Unobtanium.

Not true, this bracket is easily obtainable:

https://www.ebay.it/itm/322573135919

https://www.ebay.it/itm/181908397165

https://www.ebay.it/itm/352673913843

https://www.ebay.it/itm//321743605317

https://www.ebay.it/itm/282263752503

The stock bracket is flat...

Flat, but with the sides turned up to add rigidity.

 

[Jeff Stich]

Where does the bracket attach to, I hope not the chassis.

The exhaust bracket bolts to 2 studs on the underside of the transmission case.

 

[kco2949785]

I found an extra one. I have three and have two 128SL's so a third one is redundant. With the square steel tubing you could make one like the one shown above. I can give you the dimensions (lenght, width, and where the holes are) of the stock part. Or you can buy the extra one.

 

[Agnelli]

Check to make sure you don't have a '74 X1/9 exhaust manifold (instead of a '74 128 manifold). This will cause constant issues at this gasket joint due to system misalignment (btdt).



Not true, this bracket is easily obtainable:

https://www.ebay.it/itm/322573135919

https://www.ebay.it/itm/181908397165

https://www.ebay.it/itm/352673913843

https://www.ebay.it/itm//321743605317

https://www.ebay.it/itm/282263752503

Jeff -

Many thanks for advising. Not 100% sure on the manifold type (no numbers on it), it may be Yugo or 128. It seems to fit well so I don't believe it to be X1/9.




Flat, but with the sides turned up to add rigidity.

Jeff -

Many thanks for advising. Not 100% sure on the manifold type (no numbers on it), it may be Yugo or 128. It seems to fit well so I don't believe it to be X1/9. I did end up buying the correct factory bracket from Ken.