Comparing Tacoma Coil Over Shocks - August 2004 Off-Road.comToyota Tacoma Comparing Tacoma Coil Over Shocks
Publish date: Aug 1, 2004
By: Jesse Katz
Source: Toyota at Off-Road.com
Publish date: Aug 1, 2004
By: Jesse Katz
Source: Toyota at Off-Road.com
Plus Glossary By Jesse Katz and Sean Estes
"Trails Less Traveled" Toyota 4x4
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 . GLOSSARY
-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.