SUZUKI RM-Z250 AND 450 YOSHIMURA PERFORMANCE PACKAGE
VOL. 51 ISSUE 8 FEBRUARY 25, 2014 P73
muffler, especially at idle. It did,
however, have a much beefier
and more pleasing tone overall,
sounding much like the factory
Suzuki race bikes that Yoshimura
provides pipes for. Any noise in-
crease was heard at high rpm lev-
els, not so much down low.
Both our bikes responded well
to the Yosh pipes. Although both
bikes already make very good
power, the Yosh pipes "wakes
them up even more,"
said our chief test rid-
er Jason Abbott. He
was impressed by the
noticeably increased
bottom-to-mid perfor-
mance in both bikes and
increased over-rev with
the 450. When it comes
to on-track performance,
we experienced zero negative
side affects, just positives with
the Yosh RS-4 pipes.
Our dyno confirmed some
of our track findings. On paper,
we saw slight horsepower gains
with both bikes with no real ad-
verse affects. The dyno revealed
that the 250 experienced decent
power gains from bottom to mid,
as well as torque. Max torque
and power, however, remained
similar to stock. The 450 showed
a bit more grunt in the first half
of the powerband and a bit more
over-rev with the RS-4 system.
It's in the weight department
that we saw significant differ-
ences. On our scales, the RS-4
(Left) You have the choice
of the RS-4 Yoshimura
steel exhaust system and
all the goodies (pictured)
or the lightweight RS-4
titanium system without
the goodies.
(Below) The RS-4
Yoshimura mufflers with
carbon-fiber tips look like
a piece of art.
steel/aluminum exhaust system
for the RM-Z250 proved to be
about two pounds lighter than
the stock exhaust, while the RS-4
exhaust system for the RM-Z450
about three pounds lighter. Both
pipes weighed a little over six
pounds each.
Worth the $600 in Customer
Cash that you'll be conceding
for either one of these two per-
formance packages, you ask?
Sure, says Abbott, especially
with the option-two package.
You'll have one of the coolest
looking bikes on the track and a
durable exhaust system that actu-
ally improves performance. From
our past experiences, steel/alu-
minum exhaust systems are gen-
