Pacifica - Dual Exhaust Suggestion

per Art Begun:

Art, the Pacifica may need more power, but dual exhaust is not the answer.
Dual exhaust is going to add a lot of weight with extra exhaust piping, cat
converter, muffler, and resonator. This will make the car slower, not
faster.

It was the de rigueur for high performance motorcycles like the Royal
Enfield to have dual pipes. But, have you noticed that the best bikes
today like the Ducati only have one exhaust? And slugs like the Harley lug
around two. Duals may look nice and sound nice, but they are so retro.

For the Pacifica, one large pipe big enough to carry out the exhaust
without back pressure is lighter than two of equal capacity. In this case,
D-C has made the correct choice going with a single exhaust of adequate
size. You will also note that exhuast restriction plays a secondary role to
induction restriction; that is why a TURBO gives you so much more a boost
than duals could any day of the week. But a TURBO is going to cost a lot
because when Chrysler first starting doing turbos, they used an Air-Garrett
with OIL AND WATER cooling. The Air-Garrett was bullet proof. Insist on
Air-Garrett for a trouble-free turbocharger installation.

 

Maybe maybe not.

Student Mechanic where do you get your ideas from? You know even less
about motorcycles than you do cars.

Hi Pro motorcycles have one pipe because the entire exhaust system is
tuned to the upper power band. Bike engines have to be small and light
and powerful, and the faster you can spin the crank the more explosions
per second you can get, thus the more power, so designers can only meet
the power demands on a small engine by spinning them faster and designing
everything accordingly. At these higher RPM's the exhaust system can
scavenge if the system is tuned for it, in short not only is there no back
pressure
there's actually a negative pressure there in part of the exhaust cycle that
literally sucks the exhaust right out.

Car exhaust systems are not tuned, at least not the entire system. The
headers
can be but the cat-con and muffler prevent the rest of the line from being
tuned,
and in addition people and
municipalities would not tolerate the loudness of a tuned exhaust. Bikes
can
get away with this because there's fewer of them and people expect
motorcycles
to be noisy. Also, car exhaust has to be dumped at the rear bumper or you
can suck it into the passenger compartment, thus the exhaust line has to be
much longer than optimal for tuning. Finally, the benefits of a fully tuned
exhaust
vs just tuning the headers aren't that much better.

Because of this, the better flowing the exhaust is, the less backpressure.
Granted
that 2 smaller pipes flow less than 1 bigger one, but 2 bigger pipes flow
even better
than 1 pipe of the same diameter. So while putting dual exhausts on a car
may not
gather that much more power, it's always better than a single exhaust,
assuming
equal sized pipes.

Ted