Reply to "mufflers or not?"

> When I took the cat back exhaust off my 5.0 mustang years back, it was
> actually louder with the new flow master than when nothing was there.

With your Mustang, the four catalytic convertors were doing quite a bit of
muffling. I have a Ford Motorsport off-road H-pipe without the catalytic
convertors and can confirm it is much louder without mufflers. However, you
can generally find a particular RPM (and it's harmonic) where it will be
fairly quiet but once off that RPM it will get very loud.

> Do these mufflers such as ansa, pim, mindtrain, etc. actually make the car
> louder?

No. An open header Pantera will be much louder than a muffled one.
If the mufflers have fiberglass packing and the packing burns out, it will
get quite loud. I've seen that with Hall big bores. Note than many of the
Pantera mufflers I've tested have been real power killers. For instance,
the ANSA Euro GTS mufflers lost 50 HP on a 400+ HP 351C. I've got a set
of Wilkinson's new stainless Euro GTS mufflers to test. Magnaflows (both
2 1/2" dual outlet and 3" single outlet) have performed quite well (zero
loss on the 400 HP engine and only a few HP loss on a 569 HP 403C).

> For some reason I have this idea to create some tailpipes that are similar
> to these from PIM, except that they would only be tailpipe, no muffler,
> glasspack, etc....

Depending upon the design, the muffler can change the apparent collector
dimensions. Some will appear as a wave termination, others as an collector
extension. With our very short collector length, this can effect the optimal
cam timing.

Dan Jones