A Major Steeda Innovation – Steeda’s Watt’s Linkage

April 30, 2008 2:59 pm

The Steeda Autosports Engineering Team latest creation is the most technologically advanced and best performing suspension upgrade you can provide for your 2005 through 2008 Mustang…

Steeda’s Watt’s Linkage

Under development for an extended period of time, Steeda Engineers using ISO 9001-2000 Certified Procedures, have set a new benchmark standard for Watt’s Linkage suspension systems for the Ford performance enthusiast. Do not be fooled by advertising hype into thinking that all Watt’s Linkage systems are the same – because they are not.

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Rather than rushing to market like many of our competitors have done and potentially providing inferior products that do not provide the best possible performance attributes, we took our time and designed it the right way from scratch. Our company founder, Dario Orlando, has always mandated that if the Steeda name is on it, it has to be the very best possible, he would not have it any other way.

We started with a “blank sheet”….doing extensive product evaluations and engineering simulations to form a basis for the current suspension dynamics on the Mustang. Then we combined our ISO Certified design process, engineering procedures, and computer animations along with real-world performance track driving sessions with the 2005-present Mustang to re-invent the best Watt’s Linkage upgrade possible for your vehicle.

Remember – Anytime you give our most experienced and senior engineers a “blank sheet” and unlimited budgets and tell them to go do it – you know for certain that the end result will be something really great…and it certainly is! The end result is the Steeda Watt’s Linkage that is all new and a definite “step above” EVERYTHING available today in the marketplace. When you combine this rear suspension element with the other track tested and proven suspension products, you will certainly end up with a suspension system that is the very best available anywhere.

Following is a technical discussion that fully explains the Steeda Watt’s Linkage suspension system upgrade:

What is the purpose of a Watt’s Linkage?

A Watt’s Linkage is used as the lateral positioning element in a multi-link suspension where the other links do not provide any (or minimal) lateral positioning.

Which part does a Watt’s Linkage replace in an S197 Mustang?

A Watt’s Linkage replaces the Panhard Bar that was added when Ford re-designed the suspension and made the trailing arms parallel with the length of the chassis. When all of the trailing arms were made parallel, they no longer provided lateral (side-to-side) positioning by themselves (as they did on the Satchell Link of the Fox/SN95).

What is wrong with a a Panhard Bar?

As the body mount of a Panhard Bar rises and falls with suspension motion, the axle moves laterally with respect to the chassis due to the arc described by the Panhard Bar. This, in effect, binds the suspension; preventing it from moving to where load transfer and geometry would like it to be. Therefore, the lower the movement the better. A perfectly set up Panhard Bar (that is, horizontal at ride height) with a length of 42.5″ (about what the S197 is) has a lateral motion of about 0.189″ (roughly 3/16″ or 4.8mm) toward the passenger side for 4″ of travel in both bump and rebound. When the Panhard Bar cannot be set up perfectly, the amount of lateral movement increases in either bump or rebound (depending on which end of the Panhard Bar is lower). Further, since the axle moves toward the passenger side in both bump and rebound, there is a different cornering characteristic when turning left vs. right.

Why is a Watt’s Linkage better?

A Watt’s Linkage nearly eliminates lateral motion in the middle of its operating range. With the lateral and center link lengths that Steeda uses, the lateral motion for 4″ of bump travel is about 0.018″ (roughly 1/64″ or 0.46mm or 1/10 of the Panhard bar amount). At 4″ of rebound it is about 0.017″ (again, about 1/64″ or 0.43mm or 1/10 of the Panhard bar). At 2″ of bump/rebound travel, the Watt’s Linkage is even more impressive. The Panhard Bar has moved 0.047″ (1.19mm) while the Watt’s Linkage has moved less than 0.001″ (0.0005″ or 0.01mm). This reduced amount of lateral motion allows the suspension to react to cornering forces in a more consistent manner. The wheels will be able to track the road more consistently. From a driver’s view, the axle will feel better controlled when, for example, encountering a bump or dip during a turn. The rear end will feel more connected and stable to the chassis. Because the lateral movement is near zero, the left vs. right turn dynamics are effectively eliminated. Another minor point is that since the axle locates consistently between the wheel wells, a slightly larger tire can be used without fear of rubbing the tire.

Why is Steeda’s Watt’s Linkage better than others?

The Steeda Watt’s Linkage is better than the rest because it is fully adjustable while maintaining proper geometry (that is, horizontal lateral links and vertical center link at ride height). On a Watt’s Link-equipped vehicle, the center pivot of the center link is the rear roll center. Moving the center pivot up or down moves the roll center up and down. Further, the lateral links should be horizontal and the center link vertical with the vehicle at ride height. When the links are not set up horizontal at ride height, there can be significant increases in scrub in one or both of the travel directions. Steeda’s design allows an adjustable roll center while maintaining proper geometry of the Watt’s Linkage to give minimal lateral movement. Steeda also uses polyurethane on both ends of the lateral links for decreased NVH (noise, vibration, harshness) over competitive designs.

Why should I buy the Steeda Watt’s Linkage upgrade for my Mustang?

This product is for the most discerning street performance enthusiast and also for those tracking their car. The loose axle feeling with the Panhard Bar (due to lateral axle movement) doesn’t always inspire confidence when tossing the car around. The more stable feeling with a Watt’s Linkage should allow a typical driver to control the car closer to the vehicle’s limit.

This product will become available during the month of May. Make sure to check back on Steeda.com for more info!