This is story of building the true dual stainless exhaust system.

I planned  to make a true dual exhaust system to my car. I looked for a mufflers that are with 2 x 63.5 mm inlets and got frustraded finding a proper ones, so I decided to make it myself :) The space under the car is quite limited in some places, so there is lots of measurements and fitting tests to be made.

First I had to get perforated pipe to the muffler inside, and I found a good machinery shop who made me a perforated plates. Then those had to make from flat to round pipes. The absorption material is basalt stone wool which is especially ment for mufflers.

Then a little bit a twisting and turning, and those started to look like pipes.

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Then I started to make the muffler housing. I cutted the plate and then started to bend it. After the case was done, the ends were next. All weldings are made with stainless steel with MIG or TIG. After everything are welded, parts are going to acid "bath".

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First I thought that I'm going to buy the tail pipes, but then got an idea how to make them look like rolled. I took 63.5 mm pipe to the inside and 73 mm to the outside. Then I made a "rolling tool" using lathe and 60.3 mm pipe. The smaller pipe works as a guide so the tool wont turn sideways. Then i just hammered the tool in to the 63.5 mm pipe, and the edge rounded nicely. The edge is just enough wide so that it fits tight inside the 73 mm pipe. There is a litlle bit "fine tuning after the welding, but not much. Now the tail pipes wont look so "homemade" when the edge is rolled. These next 6 pictures are taken with a Nokia N90 camera phone, BTW.

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First fitting test for the end muffler, and it fits there perfectly!  Here is the end of the exhaust system ready for welding. It was really painfull to get it fit! It took many hours, but now it is done. There is only one centimeter space in some places.

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These pictures are after welding, but before the acid.

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Here is the acid spreaded to the exhaust pipes.

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Here is the "final" product, after the acid treatment. The surface is very neat, and the weldings look good. 

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finished2.jpg (204674 bytes)finished3.jpg (171873 bytes). end_muffler_ready.jpg (161758 bytes)finished4.jpg (187629 bytes)

I used V-band clamps to connect downpipes to exhaust pipe, those are great! :) Downpipes are made from 76 mm pipe. Those fit in the car quite well. Catalytic converters are Magnaflow's stainless steel free flow models.

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Now the exhaust system is installed, and it works great! The sound is perfect, quite low and not loud at all, and it doesn't rattle. I try to record the sounds sometime...

Great thanks to Leksa for all the tools, stuff and space and  Mirko for the TIG welding and the acid treatment! I also want to thank Fennosteel of their help.

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