[s-cars] RE: Mandrel Bend Confusion

Robert Pastore rpastore at animalfeeds.com
Mon Jan 20 10:49:46 EST 2003

Every one of us fanatics "knows" we want a mandrel bent system -- after all
"Mandrel Bent" is part of the mantra we learn with the HP addiction.
I found myself a part of this group, but was uncomfortable talking out my
*ss about mandrel bent this and that, but not knowing how to tell the
difference between what is and what isn't mandrel bent.

If I am the only idiot out here who doesn't know the difference, sorry for
the WOB, and you can close this message now.  For the rest of us, I did dome
research myself to learn the differences. "Mandrel-bent" means simply that a
steel ball or other piece is inserted **INSIDE** the tubing as it is bent to
ensure that the inside diameter remains constant. The typical PRESS bends
made local exhaust shops REDUCE the interior diameter of the pipe  for a
significant loss of flow capacity.

The typical mandrel bending equipment is huge -- it just won't fit into your
average muffler shop.  Here's a link showing a typical mandrel bending

Compare this to the press bender in your local shop:

Many are fooled into believing a hydraulic press bender is a mandrel bender.
It aint!

Since mandrel bent bends are readily available (from Burns Stainless and
others), many "performance shops" will simple buy the mandrel bends and weld
up a system.  The system that Mufflex (in Trenton NJ) built for me is done
this way and it sounds like Norm at Fantasy Fabrications builds his systems
the same way.


-----Original Message-----
From: Peter Schulz [mailto:peschulz at cisco.com]
Sent: Monday, January 20, 2003 9:06 AM
To: S4audinut at aol.com
Cc: wmahoney at disk.com; s-car-list at audifans.com
Subject: Re: [s-cars] Stromung, worth it?


Can you further comment on the "not mandrel bent"...

Did Norman take short sections of bends and weld them together?
Or do the pipes have that "corrugated"' look?


>Guys, Norman of fantasy fabricarionsb in concord NH  built me one out of
>steel and it is the finest setup I have ever seen on any car. Looks better
>than some of the 2000$ systems I have seen. I use no cat, a dynaflow center
>and a new stainless rear muffler from Thermo tec. I got the thermo tec for
>349$ (the finest piece I have ever seen and all parts are replaceable with
>any size in or out single in dual out any combo of sizes. I have a total of
>850 $ in this and it includes everything. It was not mandrel bent. You can
>get really good value from a good shop and the right components. This is a
>very high flow system yet is not boomy and sounds aggresive at full chat
>not loud around town. Every car is different and to me the ultimate setup
>tailored to your car. That said the Stromun? systems are pertty good but
>a bit pricey if you have a local craftsman.
>S-CAR-List mailing list
>S-CAR-List at audifans.com

Peter Schulz
1990 CQ
1991 200 20v TQW indigo mica
1991 200 20v TQW titanium grey
Chelmsford, MA USA
peschulz at cisco.com

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