FOR THE ULTIMATE
WE TEST FIVE SYSTEMS—AND YOU ALREADY OWN ONE OF THEM
xhaust-system testing is
simple to do but complex to
analyze. The MXA wrecking
crew gathered four test riders of dif-
ferent skill levels and had them race
with all the YZ450F pipes in this test.
Next, we rallied them for an all-day,
round-robin pipe test that involved
riding, changing pipes and filling in
test reports. Finally, we took the 2014
Yamaha YZ450F to the dyno and ran
each pipe through its paces to get
cold, hard, statistical facts to compare
with the test riders’ opinions.
That was the easy part. The
complex part was trying to make
sense of what the riders liked, didn’t
like and thought of each exhaust
system—and to put that information
into a cohesive report given the
variables of speed, skill, dyno data
and personal taste.
To keep things simple, we applied
these 10 rules.
(1) We asked each company to
send us the pipe they wanted us
to test, and we tested the exhaust
pipes as they were sent to us. Thus,
the DR.D, FMF, Pro Circuit and
Yoshimura pipes were taken out of
the box and tested. We didn’t install
any reducers or spark arrestors.
( 2) We raced the bike with
numerous test riders over the course
of two months, but for the final
round-robin showdown, we used
four test riders—a Pro, Vet Pro,
Intermediate and Novice. With our
aftermarket exhaust pipes, we ran
the stock 0/0/0 mapping numbers.
We have a better map, which we
have included in this story, but we
did not use it during the YZ450F
pipe shootout because each pipe was
built to run the stock 0/0/0 map.
( 3) Test riders were not allowed
to talk to each other about the
pipes they had tested until all the