Although it is a major undertaking to install an independent rear suspension in a classic muscle car, it is a very popular upgrade for the true performance enthusiasts. Art Morrison Enterprises (AME) understands the popularity, and wants to give those enthusiasts a great IRS for their car. The AME Multilink IRS is an all-assembled, almost ready-to-install kit that is waiting to be bolted into a chassis. Because it has its own subframe, this IRS is great for installing into unibody cars, those with an original chassis or with an aftermarket frame. The suspension comes in a choice of three different cradle sizes and four different track widths. These various attributes make this an option for just about every vehicle out there.
AME has taken many steps to ensure a high-degree of performance delivery with its new suspension system. One important aspect to aid in obtaining this performance level, is the available adjustment of the toe-link eccentric, which is preset at Art Morrison Enterprises.
The adjustment of the toe link does not adjust actual toe in/out, but actually the toe curve or “bumpsteer.” The bumpsteer curve has been engineered in a way to steer the rear of the vehicle into a corner in a safe manner. The adjustment of the eccentric will control the amount of steer experienced while cornering.
Track vehicles will greatly benefit from this method of adjustment, as it allows high-horsepower vehicles to control the effects of throttle steer. Those wanting to improve how their street car handles, you will feel an enhanced turn-in response that further enhances vehicle control. Art Morrison Enterprises will have a pre-set adjustment that will work for most vehicles that will enhance handling without adding oversteer.
When asked to evaluate the handling of a Multilink IRS-equipped 1969 Camaro, test driver Mary Pozzi summed it all up by saying “This is the best suspension I’ve ever felt underneath a car on a track.” That’s an endorsement worth mentioning.
It’s important to understand that not all independent rear suspension systems are the same. Early IRS setups, like those used in Jaguar, Cobra, and C2/C3 Corvette (which have been mimicked by several aftermarket manufacturers), have a number of disadvantages. These include poor toe and camber control, little anti-squat and spindle support, limited wheel-offset fitments, and require a relatively large “package.” They also have horsepower limitations.
The Art Morrison independent rear suspension can trace its design lineage to a number of the world’s most renowned exotic automobiles. There are a number of important advantages to the new Morrison Multilink IRS; all of which add up to optimum handling and long-term dependability.
Technical Features and Benefits
Functionally Independent Design.
The decoupled links allow changes to one parameter without affecting others. For example, during the design phase we were able to make an adjustment to the camber curve with little or no effect on the roll center. This gives you the freedom to set the car up for optimal handling under varying conditions.
Direct Load Paths
Through use of decoupled lower links, a direct-load path is created that prevents control arm failure. Moreover, most bushings are loaded in their radial direction for maximum stiffness.
Superior Knuckle Support
Typical wishbone designs attach at three points in single shear. The Morrison Multilink IRS has four attachment points to control freedom of movement, three of which are double-shear attachments.
Improved Wheel Control
With the AME Multilink IRS you can establish functionally independent camber, caster and toe curves. Moreover, critical toe-link locations can be tuned to allow dynamic steering while maintaining stability in high bump situations.
Ride Quality Improvements
Unsprung vehicle weight is reduced by approximately 100 pounds, requiring less spring rate to control wheel movement. NVH (noise/vibration/harshness) is reduced because it must travel through three sets of bushings before reaching the driver’s compartment.
Unique Cradle Design
Not only does this facilitate installation of the Multilink IRS in most Morrison GT Sport chassis, but makes it easily adaptable to other vehicles. It can be aligned to the vehicle during installation and provides excellent serviceability. Loads from the coilovers transfer to the vehicle frame, not the suspension cradle.