By Dale Wilson
a 160-mph bracket dragster is just as important
as its starting line leave, and for our new
front-engine dragster built by Tommy Harris/Fabrication
Concepts (Douglassville, GA), we chose a new
brake kit from Wilwood Engineering. It is ultra-trick.
Why? Wilwood's Carl Bush explains the ins and
outs of the company's new Dynamic Mount dual
caliper rear axle drag brake system. (Also available
but sold separately is Wilwood's dual tandem-outlet
master cylinder that operates two separate and
isolated brake systems on the rear axle.) "We've
added the additional brake-clamping force of
the second calipers, and it therefore becomes
a redundant system in case half of the braking
system should fail; if it does, you still have
two more brake calipers to stop the car," Bush
That means that Wilwood's Dynamic Mount braking system has four calipers, two per wheel, that act as two separate and independent pair. Two of the calipers are in front of the axles and two are behind them. "You essentially have front and rear brakes, two in front and two in the rear of the axles," he said.
What a dragster sees is very high brake torque loading and very high temperature spikes into the brake system, Bush said, even though it's only for a short period of time. "The key to the system is how the steel rotors are attached to the mounting hats," he said. "The rotor is able to expand and contract or 'float,' and that's where the 'Dynamic Mount' comes in, as opposed to static mount, where the rotor is mounted directly to the hat. Our rotor is mounted in a T-hut and slot system that allows the rotor to move independently of the aluminum mounting hat. It completely eliminates all the stresses and strains that would otherwise be imposed on the mounting bolt circle trying to also expand and contract." Meaning this Wilwood Dynamic Mount kit dissipates heat a lot quicker and better than other disc systems.
assembly, made of steel and aluminum, is also
lighter than other systems, thus not only cutting
down on overall weight, but rotating weight
or rotating mass as well. "It stops rotor warpage,
the rotors run more true and it eliminates all
that stress in braking," Bush said. "You'll
get a long longer service life out of these
rotors and of the hats," he said. Plus I'll
be stopping a lot quicker --- very important
in top end bracket or "Super/Rod" racing.
Photos courtesy of Wilwood Engineering
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check out this month's column by Dale Wilson.
4700 Calle Bolero
Camarillo, CA 93012