C1 Corvette Sport Chassis - Frame Job

Deconstructing Art Morrison's Criminally Cool GT Sport C1 Chassis

Bill Holland Jul 17, 2007 0 Comment(s)
Vemp_0702_01_z AME_c1_corvette_chassis And_suspension_package 2/19

This is what AME calls its "chassis with suspension" package. Everything you see is included in its $12,020 price tag.

As best we can tell, C1 Corvette owners can be divided into three different categories. Those in the first group prefer to keep everything absolutely original. To them, any variation from stock is something akin to heresy. Category number two's members are a bit more open-minded, going so far as to make subtle changes to enhance their vintage Vettes. Finally, there are those radical few who are willing to do whatever it takes to improve the performance of their rides. For them, noted chassis builder Art Morrison has developed the C1 GT Sport chassis.

Although Art Morrison Enterprises has been cranking out a variety of top-quality frames for more than 30 years, it wasn't until the Fife, Washington-based firm introduced its bolt-in GT Sport chassis for '55 to '57 Chevys that it hit its first home run. Thanks to a sophisticated independent front suspension and triangulated four-link in the rear, the chassis gave "shoebox" Chevy owners a vehicle with sports car handling and a superb ride.

The new Morrison GT Sport Corvette chassis offers even more stunning performance, providing contemporary suspension technology to replace the over-50-year-old C1 frame. It will also make an excellent platform for a ground-up "kit car" using one of the several available fiberglass C1 replica bodies. Talk about a pedigree. When word of the new chassis came out, noted hot-rodders such as Boyd Coddington and Chip Foose were among the first in line. Coddington's '54 Vette project was even featured on the car builder's popular SPEED TV show, American Hot Rod.

Vemp_0702_02_z AME_c1_corvette_chassis Core_support_mount 3/19

The chassis abounds with helpful touches, including a core-support mount and tabs to mount the stock license plate.

The Hardware
What makes the GT Sport chassis tick? For starters, it employs a C5 Corvette front suspension, with forged aluminum control arms and fully adjustable Strange Engineering coilover shocks. But there's more to it than simply slapping some trick A-arms in place. The entire chassis has been computer-engineered for optimum handling and zero bumpsteer, so it can corner with the precision of a slot car. Because the body of the C1 is more narrow than that of later-model Vettes, the track width has been narrowed, and AME's engineering department slightly increased the scrub radius for better driver feedback. With 9-inch-wide front wheels and 6.5-inch backspacing employed, everything is contained within the stock wheel wells. The front-view swing-arm arc has been shortened to maintain better camber angle during cornering, while the static roll-center height has been reduced to minimize side scrub and jacking force. As a result, straight-line stability and ride quality have been enhanced.

The rearend features a triangulated four-link suspension. This is a "best of both worlds" situation in which the upper, angled bars provide lateral stability while the lower bars control housing "wrap" under hard acceleration. And if you're wondering why a C5 IRS is not employed, it's because the C5's track is too wide to fit under the C1 body. The C5 setup is also quite costly.

Steering is handled through an AGR power rack. This hydraulically augmented system is offered in 15:1 and 20:1 ratios-which equate to 2.5 or 4 turns lock-to-lock, respectively. The former is best suited to aggressive driving on winding roads, while the latter is ideal for highway cruising.

Vemp_0702_03_z AME_c1_corvette_chassis Steering_rack_installation 4/19

Morrison attaches the AGR power rack to the frame. The rack is available in both 15:1 and 20:1 ratios.

Excellent braking is achieved through use of the 13-inch front discs from the C5 and an SVO rear-disc kit. For even more braking power, Wilwood six-piston calipers and 14-inch rotors are available optionally.

The frame itself is made from mandrel-bent 2-by-4-inch rectangular tubing, which is fixture-welded by AME's experienced craftsmen. To ensure perfect alignment, the core support and suspension, body, engine, and transmission mounts are installed while the frame is in the jig.

Among the most important features of the AME GT Sport chassis are the in-frame passages that allow the exhaust system to be routed through the framerails. This allows for a lower-than-stock center of gravity while also maintaining ample ground clearance.

A wide variety of drivetrain combinations can be employed, as there are motor mounts available for both the traditional small-block Chevy and the newer LS-series powerplants. Most manual and automatic transmissions will also fit.

Vemp_0702_04_z AME_c1_corvette_chassis Antisway_bars 5/19

Special antisway bars are employed to reduce body roll while cornering. This helps the GT Sport chassis provide handling that's purportedly equal or superior to that of most expensive exotics.

The Installation
What's involved in retrofitting a C1 Corvette with a Morrison GT Sport chassis? The operation is actually straightforward and can be accomplished by a competent do-it-yourselfer with access to a well-equipped garage.

To start the process, it's necessary to disconnect any items that would prevent the body from being lifted off the chassis, such as steering, pedal linkages, brake lines, and so on. Then it's simply a matter of unbolting the OEM Corvette body and core support and plucking the body off the frame. Morrison recommends using a two-post lift, with the arms positioned just in front of the door opening and forward of the rear wheelwell. The body will lift off in one piece.

After the body is removed, some minor altera-tions will be required prior to re-installation. First, the inner-fender panels will need to be trimmed slightly to clear the C5 suspension. Next is the issue of the transmission tunnel. Most aftermarket trannies will clear, with the exception of the T56 six-speed. This trans is fairly wide in the back, and the tunnel must be expanded accordingly.




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