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Kroeker Off-Road Engineering
(KORE) founder and CEO Kent Kroeker is a real thinking man's
thinker when it comes to the design and manufacture of
high-quality suspension components for off-road vehicles. A
former Marine Corps pilot, Kroeker has consistently set
lofty performance goals for all parts that bear the KORE
name and then applied military-like discipline to achieve
those goals. KORE's newest long-travel front suspension
system for the Dodge Ram 1500 and new "DS" Ford F-150 and
Toyota Tundra trucks is a perfect example of KORE's
problem-solving philosophy.
"The problem is that the
average guy who buys a nice, new half-ton pickup is very
reticent to change his bodywork to accommodate longer
A-arms," Kroeker says. "He wants the performance of long
travel but doesn't want to chop up the body on a $30,000
truck, so he settles for drop bracket/spindle lifts. Fire
years later a kid from Norco buys the truck and the first
thing he does is whip out his plasma cutter and install a
long-travel kit with glass fenders."
KORE's goal was to attain 12
inches of real travel as measured at the spindle for Dodge,
Ford and Toyota 4WD IFS trucks, three brands that feature
similar front suspension designs. However, the real design
mission that KORE accepted was to create a long-travel
suspension system that retains the stock track width on
these vehicles. That's a very tough assignment when you take
into account the geometry that's involved.
The real trick is in
retaining 4WD, and the OE half hafts simply aren't up to the
demands of long travel. The outboard CV, which goes through
the spindle on the steering side of each half shaft isn't
the problem. It can handle up to 30 degrees of motion as the
suspension swings through its arc. The inboard side,
however, is only good for about 16 degrees -- not nearly
enough to handle the demands of a long-travel system that
retains the stock track width. Of course, the time-honored
solution has been to increase the front track width.
"It's pretty easy to increase
travel by increasing the length of the arms because the
geometry becomes less critical," Kroeker says. As the angle
becomes more oblate at every pivot point, you require less
movement. But our goal was to keep everything inside the
stock fenders."
That said, it is important to
note that the new KORE kits are not designed for racing.
"These kits are for uncaged vehicles -- to provide comfort
over washboard and cross grain -- but not to get on top of
big whoops," Kroeker says. "These are mass-market kits that
we've designed to require no body work because we're not
using long A-arms to reduce pivot-point angles."
So how do you attain 12
inches of travel without increasing the track width? It's a
tough challenge, but KORE has come up with a brilliant
solution. To break new ground in suspension technology,
Kroeker turned to 1970s engineering, the Porsche 930-style
CV joint.
"As the A-arm moves up and
down, the axle also has to plunge back and forth because the
relationship between the axle and the differential changes
ever so slightly -- about an inch," Kroeker explains. "The
930 CV also moves in and out as well as at an angle. We
could do an entire half-shaft replacement, but the OE part
is basically a good part. So here's a new piece that you
just open up, undo everything, pop it in with a circlip and
just slide it in place."
"The other critical thing is
the adapter," Kroeker adds. "In a Dodge the CV is female to
the axle stub, whereas with the Ford and Toyota, the stub is
the female part. So we make an adapter that allows it to
work with our 930-style CV, which has cooling fins to fight
friction-induced heat as the inboard CV angle is increased."
Like the outer CV joint, the
lower A-arm has no trouble withstanding the demands of a
long-travel suspension, but the upper A-arm's geometric
disadvantage is similar to that of the inner CV joint -- not
enough arm length creates too much angle through the
suspension arc. As suspension travel is increased, the angle
of the ball joint becomes so acute when the suspension is
compressed that the ball joint is taxed severely. To retain
the stock A-arm length, KORE designed a stout billet
aluminum upper control arm with a unique, rebuildable
high-angle ball joint that is asymmetrical, featuring more
throw in the outward direction the ball joint moves when the
shock is extended and less throw in the opposite direction
when the suspension is compressed.
The spring is the third
critical design parameter in the KORE kit. Working with
Eibach, KORE developed a special spring with the right
length and the right wire diameter to be able to work with
the suspension. The spring is designed to produce a
tremendous amount of travel for its length.
"It's not just some
off-the-shelf spring," Kroeker says. "It has a very light
spring rate that is similar to stock. An additional 2.5 to 3
inches of lift is achieved by lengthening the overall
coilover assembly, increasing the spring rte or simply
adding preload. With the motion ratio of these trucks, we
needed to develop a spring with the proper spring rate but
also one that would cycle enough. If you just have a spring
with 7 1/2 inches of stroke and 2 inches of preload to set
your ride height, you will bind the spring as it collapses.
You won't even be able to bottom the suspension out on the
rubber bumper or bumpstop."
What you get when you combine
all these parts is a suspension kit that is truly on the
cutting edge -- the pointy end of the spear, as Kroeker
likes to call it. The KORE kit requires no drilling, welding
or cutting. It is a 100-percent bolt-on, fully rebuildable
long-travel kit that permits 35-inch tires in the OE wheel
house. Until now, nobody has offered this kind of package,
and it took KORE over two years of R&D to bring it to
market, but now there is a long-travel system that could
take the notion of long travel out of the realm of the
back-yard fabricator and place it firmly in the mass market.
The idea is that eventually the very concept of the "lift
kit" could be changed forever. |
KORE's new long-travel suspension kit for Dodge, Ford and
Toyota 4x4 trucks is designed to offer 12 inches of front
suspension travel while retaining the stock track width.
Eliminating the need for longer A-arms, longer half shafts
and the flared fenders usually required by long-travel
suspension kits, the KORE kit retains the stock bodywork on
your ride.
KORE's billet aluminum upper A-arm is virtually
indestructible. The unit's rod ends sport
nylon/Kevlar-impregnated spherical bearings for increased
durability, while the zerk fitting on top of the ball joint
makes servicing the joint a breeze.
KORE's unique upper ball joint features a
housing (right) with an asymmetrical slot to handle the
wider swing of the ball joint. The "slug" that rides atop
the ball joint (center) can be adjusted with an allen wrench
to remove any slop in the joint.
The trick constant velocity joint is the
heart of the entire KORE system. Inspired by the legendary
Porsche 930 CV, this CV is designed to simultaneously handle
the up-and-down motion and in-and-out (plunge) motion of the
suspension.
KORE's CV arrangement replaces the stock
CV on the inboard (differential) side of the stock half
shaft, increasing the range of motion on the inboard side
when the suspension swings through its travel arc. |
The article below covers KORE's
new Long-Travel Suspension System, which won the
