INTRODUCTION
 |
We're still using this suspension on our '96
4Runner and working to pull more than 10" of wheel-travel out of a
stock-width truck without causing the CV's to fail. |
Almost two years ago we set out to improve the
front suspension on our Toyota Tacoma. There were already quite a
few bolt-in coil-over replacement shocks on the market, but we
weren't completely satisfied with any one particular offering. We
ended up using off-the-shelf components to develop our own custom
mid-travel setup. Our Sway-A-Way 2.5x8.0" stroke emulsion shocks
and 14"x 650lb coil springs with low-profile upper shock mounts
from Total Chaos Fabrication and Total Chaos Uni-ball upper control
arms were capable of nearly 10" of vertical wheel travel. We didn't
want to exceed the stock CV shaft's maximum operating angles or
risk damaging ball-joints, so we limited the travel to 9" by using
a pair of adjustable limiting straps from Kartek. To read the
original article about the custom Trails Less Traveled mid-travel
suspension setup including a complete parts list, CLICK HERE .
As the
Tacoma aftermarket has grown, it has also become more competitive.
Tacoma owners can now choose from a number of different coil-over
shocks. But what are the differences between models, and do the
features justify the price? It can be difficult for consumers to
determine which products will suit their needs. The intended use
for a vehicle should be the first determining factor. A
full-featured shock may be exactly what you're looking for, but
many enthusiasts would be just as well off with a less expensive
upgrade. Hopefully, this coil-over comparison article will help
enthusiasts to compare product features and make informed decisions
regarding suspension upgrades. PRODUCT
OVERVIEW King:
King Shock Technology in Garden Grove, CA was one of the first
manufacturers to develop a bolt-in 2.5" diameter replacement
coil-over. The larger 2.5" diameter shock body allows more oil
capacity, which in turn dramatically reduces fade. King's shocks
also feature an internal reservoir, which further contributes to
fade-free performance. These shocks feature a top-out damper as
well as custom valving and spring rates for each application
including Tacoma's, Tundras, Sequoias and 4Runner's. They are
completely re-buildable and can be custom valved to accommodate for
specific setups such as winches and heavy bumpers or even V6/V8
engine swaps. King's coil-overs also use a readily available14"
coil-spring which makes it easy to experiment with different spring
rates. If there were a downside to the King's, it would be that
they offer no more travel than the stock shocks. King claims that
they have observed binding of the steering components when the
suspension is extended beyond the factory travel, so they limited
the shock's stroke to 4.5", which equates to approx. 7.9" of
travel. Some of the other manufactures have squeezed out a bit more
stroke resulting in up to 9.5" of wheel travel. It's a pretty big
stretch to call the relatively short stroke of the King's
coil-overs a downfall considering the overall performance and
workmanship are top-notch.  Sway-A-Way:
Sway-A-Way's 2.0 coil-overs are one of the most popular choices
among Tacoma owners looking to increase the ride height of their
truck and clear bigger tires. Sway-A-Way shocks feature billet
construction and a 7/8" hardened chrome-plated piston shaft.
Sway-A-Way has recently improved the valving with a revised piston
design and started using a longer 15" coil-spring that allows for
slightly more spring travel. More available spring travel means
that there is a wider range of pre-load adjustment before reaching
coil-bind. Although these coil-overs only feature 2.0" diameter
shock bodies, Sway-A-Way's suspension engineers still managed to
incorporate an internal reservoir for improved fade resistance.
They might not have the endurance of a 2.5" reservoir shock, but
for just over $700 the Sway-A-Way Tacoma Racerunner's are pretty
hard to beat. Donahoe:
 The Donahoe family has
been winning desert races since the late 1970's. The same attention
to detail that has brought Donahoe to the podium so many times over
the years has been paid to the design and execution of Donahoe's
new Tacoma coil-over shock. Dylan Evans and the crew at Donahoe
systematically addressed every conceivable issue before releasing
what is arguably the most advanced shock in its class. Donahoe
starts with a large 2.5" diameter shock body featuring an internal
reservoir and an advanced piston design. They chose to spec' a
NitroSteel® piston shaft for smooth shock operation and to
help prevent corrosion and rust. They also feature a top-out damper
that softens the last 1/8" of the downward stroke, eliminating
potential damage to the ball-joints and other stock  suspension components. Donahoe had custom
high-tensile chrome silicon steel coil-springs made for their
Tacoma coil-overs that offer more spring travel than the
competition and are guaranteed never to sag. The high quality
coil-springs have fewer winds which allow Donahoe to use a
relatively short 13" spring length without having to worry about
coil-bind.
Donahoe offers two models of their Tacoma coil-over, one is a
direct replacement bolt-in coil-over designed to work with
otherwise stock suspension trucks that allows for 8.75" of
suspension travel. They also offer a 0.5" longer stroke model that
is specific for Tacoma's equipped with aftermarket uni-ball upper
control arms such as those made by Total Chaos, Camburg or All-Pro,
which offers .75" of additional travel, totaling 9.5" of vertical
wheel travel. Donahoe makes one of the most expensive replacement
coil-overs available, but we feel that the extensive R&D has
resulted in the highest level of performance that we have
personally experienced in a stock-width truck. Bilstein / All-Pro Off Road:
 All-Pro Off Road wanted
to offer a simple and cost effective option to Tacoma owners
looking to enhance their suspension performance. So they teamed up
with Bilstein, maker of high quality race/OEM replacment shocks, to
develop what is arguably the best value of all the different models
that we have compared. Bilstein already made a 2" diameter 6100
series Tundra coil-over, so All-Pro simply decreased the spring
rate to 550# and designed a custom upper mount to allow the
Bilstein to fit into a stock Tacoma coil bucket. All-Pro offers
these coil-overs by themselves or packaged in a money saving kit
paired with TIG welded cro-moly uni-ball upper control arms and
differential lowering spacers.
 All-Pro recommends the
use of differential drop spacers and uni-ball control arms to help
handle the additional droop (0.53" more than the Donahoe uni-ball
specific arms which have the second longest stroke) that the
Bilsteins are capable of providing. However we are not convinced
that the stock ball-joints and CV drive shafts can handle the full
10+" of travel the Bilsteins are capable of providing. In light of
this we would suggest installing limiting straps to be safe. The
All-Pro Bilsteins use a relatively small 14mm (approx. 9/16")
piston shaft and metal sleeved rubber bushing mounts, while all of
the other shocks in this comparison have a 7/8" piston shaft as
well as 5/8" spherical bearing shock mounts. Considering the
All-Pro Bilsteins are the lowest priced option of the group at $699
by themselves or as an incredible package for $999 complete with
All-Pro's uni-ball control arms and differential spacer kit, they
are definitely worthy of any Tacoma owner's consideration.  Fabtech
Dirt Logic:
Fabtech has been in the Tacoma bolt-in coil-over game for many
years. In the past they offered a 2.0" rebuild-able shock that was
custom made by Fox Racing Shox. Recently Fabtech has shifted
manufacturing to Sway-A-Way, and they are now offering a
significantly upgraded 2.5" diameter shock. The new Fabtech "Dirt
Logic" series Tacoma coil-over features a billet aluminum upper
mount, an internal reservoir, custom valving and many other
significant improvements. Due to their large 2.5" diameter and
internal reservoir, these shocks will resist fade and maintain
performance through extended high speed off road runs. They now use
5/8" stainless heim-joints at both ends as opposed to the
metal-sleeved rubber bushings of the older offering. Fabtech offers
their new Dirt Logic coil-overs as a complete suspension lift kit
paired with rear shocks for just under $1,000. Camburg:
 Camburg Engineering of
Huntington Beach CA, is a company known for building high
performance desert racing suspension products. They offer
long-travel kits for many makes and models of trucks including Ford
Rangers, Chevy Colorado's and of course Toyota Tacoma's. The latest
addition to their extensive product line is a 2.5" diameter Tacoma
bolt-in shock. Camburg enlisted Sway-A-Way's help in manufacturing
these new shocks which have many of the same features as the
Fabtech Dirt Logic coil-overs (also produced by Sway-A-Way).
Camburgs coil-overs are custom valved, have an internal reservoir
and nickel plated shock-bodies for corrosion resistance. Contact
Camburg for more details about their new 2.5" Tacoma
coil-overs.
ACCESSORIES Uni-Ball Replacement
Upper Control Arms:
The stock upper
ball joint is the first limiting factor in the travel of IFS Tacoma
trucks. By replacing the upper ball-joint with a Uni-ball (large
spherical bearing) you can achieve different range of angularity
resulting in as much as 9.5" of wheel travel. Uni-balls also
provide an increased level of strength and reliability. The easiest
way to mount a uni-ball in the location of the stock upper
ball-joint is to integrate it into a custom upper control
arm.
Total Chaos was the first to offer a uni-ball upper control arm for
stock width Tacoma's and we were one of the first to install and
test them out as a part of our custom mid-travel setup nearly two
years ago. The Total Chaos arms are MIG welded cro-moly and feature
urethane bushings and race quality uni-balls. Total Chaos also
manufactures a tool for pressing out the factory ball-joint and
pressing in the uni-ball slug. The tool is available for about $15
and the arms will run you about $650, both are available from
Kartek.
In recent months, All-Pro Off Road and Camburg Engineering have
also released their own uni-ball arms. Both of these companies arms
feature less expensive uni-balls than the Total Chaos arms, but
aside from that they are all relatively similar in construction.
All-Pro or Camburg arms can be had for around $390-$450
respectively. Also both companies offer a substantial discount on
their uni-ball arms when purchased as a part of a complete
suspension package. Contact the manufacturers for more
details.
Diff Drop Spacers:
 All of the bolt-in
coil-over shocks that we reviewed in this article have the ability
to increase a vehicles ground clearance, ride height and in most
cases suspension travel. In order to do so they must also place the
CV drive shafts at slightly more severe angles than stock. Severe
angularity can lead to CV boot failure, which in turn quickly leads
to CV joint failure. As long as the coil-overs are set to 2.5" of
lift or less the CV's and boots should not wear out much faster
than on a stock vehicle. However the closer to stock angles you can
maintain for the CV's, the longer they will last. A few companies
are offering differential drop spacers to help remedy this
potential problem. These spacers are simple metal pucks that when
coupled with longer bolts, allows you to lower the front
differential approximately 0.5". Lowering the differential does not
require lowering the factory skid plate and therefore does not
decrease precious ground clearance. Total Chaos Fabrication, Revtek
Industries and All-Pro Off Road all offer diff. drop spacer kits
for around $30. The kit pictured above is made by Total
Chaos.
CONCLUSION
Each shock compared in
this article fits nicely into a slightly different place in the
market and they are all represent a good value relative to their
price. The purpose of this article was not to pick any one standout
or an outright winner, as much as to illustrate the differences
between the various shocks so that you, the potential buyer, can
make your own decision. Another purpose of this article is to
better familiarize you with the basic inner workings of high-end
race shocks and the related terminology. Below is a glossary of
terms used throughout this article that should help to define any
of the more common shock technology related terms. We have also
created an easy to read comprehensive spreadsheet that lists all of
the important spec's relevant to each shock reviewed in this
article,
CLICK HERE .-Shocks- Emulsion: An emulsion shock has no internal floating
piston to separate the nitrogen from the shock fluid. Emulsion (or
aeration) quickly leads to shock fade and less efficient damping
because the shock fluid changes viscosity allowing it to freely
pass through the piston and valve-shims. Reservoir: Reservoir equipped shocks (both external and
internal) feature a floating piston that separates the nitrogen
from the shock fluid in order to eliminate the possibility of
aerating the shock fluid, which quickly leads to fading
performance. External Reservoir: An
external reservoir can mounted either piggy-back (mounted directly
to the shock body), or remotely (attached to the shock body by a
flexible hose). External reservoir shocks are often used in
applications where a long shock stroke is needed in relation to
overall shock length in a confined mounting space.Internal Reservoir: Similar to an external
reservoir in purpose, but contained within the actual shock body
and not visible. Internal reservoir shocks are often used when a
relatively short shock stroke is needed in relation to the overall
length of shock. Shock Fade:
Performance deterioration due to overheating or emulsion/aeration
of shock fluid and the nitrogen charge. Excessive heat within the
shock can cause the shock fluid to thin (lose viscosity). Shocks
are usually valved for a specific oil weight and changes in
viscosity compromise the intended damping characteristics of the
shock. Shock fade is often a result of prolonged periods of high
speed driving over severe terrain such as "whoops" or braking
bumps. Piston / Valving: All shocks
feature a shaft-mounted piston (not to be confused with a floating,
reservoir piston). The piston functions by forcing fluid through
small holes (valves) for low-speed compression damping and larger
holes (apertures) for high-speed compression damping. Apertures are
larger holes in the piston that regulate oil flow via a series of
thin flexible steel washers (shims) that deflect once a certain
amount of pressure is achieved. Once the shims have deflected, the
shock fluid can pass more freely through the piston. There is a
separate shim-stack for both the rebound and compression side of
the piston and they can be individually tuned to have distinct
compression and rebound characteristics. By modifying the
shim-stack different flow characteristics can be achieved. This is
commonly referred to as "custom-valving". Stroke: The total amount of piston shaft travel within
the shock body. Also measured as the difference between the
extended and compressed length of any shock. Bottom-Out: When a shock reaches full compression (the
opposite of top-out). Top-Out: When
a shock reaches full extension (the opposite of bottom out).Eye-To-Eye (I-2-I): Distance from the
center of one shock mounting hole to the center of the opposite
shock mounting hole. Useful measurements are often taken at full
compression, ride height and full extension. Heim-Joint (spherical bearing): Often used for shock
mounts, steering and suspension pivots on race cars and off-road
vehicles. These joints allow for a high degree of angularity (when
used with hi-misalignment spacers) and are an excellent method of
attaching articulating components, although they do require some
degree of maintenance and infrequent replacement (depending on
use).
-Coil Springs- Spring
Measurements: Usually printed on the coil- spring with the
spring free length first, spring diameter second and spring rate
last. For example; if a spring reads, 1600/0300/650 it is a 16"
spring, 3.0" in diameter spring with a 650lb spring rate.Spring Rate: Measured in ppsi (pounds per
square inch). For example: if a spring is rated at 500 ppsi, then
it will require 500 pounds of pressure to compress that spring one
inch. The spring will compress another inch for every additional
500 pounds of weight placed upon it. Spring Travel: The distance in inches that a
coil-spring can be compressed before being over-compressed (causing
fatigue) or reaching coil-bind. For example: if a spring measures
16" at free length and 9" compressed, it has 7" of spring travel.
This number is important for determining the maximum amount of
pre-load that can be placed on a coil-spring before it achieves
coil-bind and therefore limits the available shock travel.Coil-bind: When individual winds of the
coil-spring come into contact with each other prior to full
compression of the suspension, resulting in a loss of suspension
travel and harsh metal-on-metal contact as the spring bottoms out.
Usually a result of using the wrong coil-springs or too much
pre-load being placed on a coil-spring. Causing a spring to reach
coil-bind can damage suspension components and may cause the spring
to sag. Pre-Load: Affects the
ride-height of the vehicle by placing initial load on the
coil-spring. Pre-load is set by adjusting a collar up or down a
threaded shock body to a desired position and then locking it into
place with either a set screw or by jamming two collars against
each other. Typically a spanner wrench is required to adjust
pre-load on an adjustable coil over shock.
www.kingshocks.com
www.swayaway.com
www.donahoeracing.com
www.allprooffroad.com
www.bilstein.com
www.fabtechmotorsports.com
www.camburg.com
www.chaosfab.com
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