2.5' downpipe vs. 3' downpipe

Andris Laivins andris@monkey-r.com
Mon, 21 Oct 2002 13:44:37 -0500


> how do you go from 2.5 to 3 smoothly?

> or are you talking about using 3 inch pipe and simply reducing it
> at the end?

Naw, don't bother trying to reduce it.  You can either buy a smooth
transition section from someplace like burnsstainless.com, or any
good exhaust-supply kind of place and butt-weld it between the 2.5
and 3" pieces (this is the smoothest way to do it).  sometimes I just
swage (expand) the end of the 2.5 bigger until it fits snugly inside
the 3" piece. It's not as smooth, but if you expand it progressively,
it's not too bad.  Then weld.   Check out :

http://www.burnsstainless.com/Transitions/transitions.html

That is the nice way to do it, but they charge out the butt for
those.  I'd bet if you hunt around, you can find them cheaper from a
non-name-brand place (burns is expensive) or even better, find a
local exhaust place that has a swage mandrel for smooth transitions
and just have them expand the end of your tube - one less weld that
way.

Hope that helps.
Andris