Exhaust flange - Engineering Design Challenge for you Audifans tinkerers

Huw Powell audi at humanspeakers.com
Thu Aug 17 19:29:15 EDT 2006

> I just want a flange. There is nothing wrong with the downpipe flare. That
> ole stainless steel downpipe is still A-OK.

If the downpipe flare is good, the one on the flange is not important.

Just get some 1/4" or 3/8" steel (or stainless) to work with.  Make two 
squares that are big enough (why two?  you'll see...).

Using a good hole saw (Lenox type, eg), cut the correct diameter hole in 
each one.

Then cut each one - not quite in half, but off-centered enough to allow 
for the kerf.

Now take the two slightly larger halves, which will make a perfect 
circle put together, and drill the corner holes.

Wrap them around your downpipe and weld them together (bring all three 
parts to a real welder, they'll have s/s rod to work with.  Make their 
job easier by grinding angles at the weld edges for them to fill). 
grind off any excess weld.

If welding is not an option, use at least 3/8" stock to start with, and 
drill holes in each half, one to pass a bolt and the other to tap for 
the bolt.  Assemble with two bolts.  If the bolts would interfere with 
your hole pattern, rotate the hole pattern 20-30 degrees.

Huw Powell



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