Radio Control Car Action

PERFORMANCEPROVEN
TRIED
TESTED
TORTURED
See the threaded holes on this flywheel? You can
easily access them from above or below the chassis,
depending on which vehicle you install it in.

BUKU SPEED TUNE CLUTCH

Buku is well known for its easy-to-adjust tuned pipes for just about every nitro engine on the market. These pipes have been around for years and achieved success on the track and among backyard bashers. But a company can’t sur- vive with just one line of products; it has to offer something new. The Buku
Speed Tune clutch is that well-thought-out new product. It’s an adjustable off-road
clutch for use on big- and small-block nitro engines. You may be thinking, “That’s noth-
ing new; we’ve seen adjustable clutches before,” but you haven’t seen anything like
this trick clutch.
out; then, when you add the centripetal
force of the flywheel, it adds more force to
the setscrews and locks them in place. The
stock setting was a great starting point, as
my truggy felt like it did before I installed
it. The track I race on is on the loose side,
so I loosened up the clutch shoes slightly,
and my traction out of the turns increased.
Just for fun, I reset the tension and then
increased it; my truck accelerated harder
out of the turns. This time, the truck had a
lot of axle-snapping power when I nailed
the throttle.
I really like this clutch and am excited
to have it in my truggy. The only problem
I see with this system is that if you aren’t
paying attention to the screws you adjust
while you turn the flywheel, you may
make an adjustment to a clutch shoe that
you already tweaked. To prevent this, I
simply marked up the flywheel at each set-
screw location so that I can tell them apart
while making my adjustments. I still have
a lot more testing to do on this clutch;
there are so many ways you can tweak
it. You can have two loose shoes and one
tight one, or maybe set each to come in at
a different rate. Only more time with the
clutch will tell. —Kevin Hetmanski
The Buku clutch consists of a flywheel,
clutch shoes, springs and shims. The fly-
wheel has three tapped holes on the out-
side edge, and they line up with one edge
of each spring. The springs are attached
to the long-wear aluminum clutch shoes.
Now here’s where it gets fancy: inside
those tapped holes are setscrews; they
apply pressure to the springs and that, in
turn, changes the spring pressure on each
of the clutch shoes. So that allows you to
adjust the spring tension on each clutch
shoe individually, and you can make your
adjustments without having to remove
any parts from the vehicle.
I installed the clutch on my RC8T FT
Championship Edition truggy. I’d been
running it for a while, and I was looking
for a slight advantage at the track. The in-
stallation took me a little longer than usu-
al because it was my first installation of
this type of clutch. Now that I understand
how it works, I’m confident it will go more
quickly the next time around. I set the
tension on the springs to the recommend-
ed settings and ran some laps. One of my
concerns about this system was that the
setscrews may loosen and fall out when
my engine was running, but that wasn’t
the case. The spring tension alone on the
setscrews prevents them from rotating