Corvette Central

Concept 57 - Chassis

Readers will remember last year's project vehicle named Rex, which culminated in one gorgeous Silver Blue 1958 Corvette, feathered on the cover of the October issue of Corvette Enthusiast. This year , we're tackling another project vehicle, and we're going a little further back in chronological order, sort of.
We're combining forces with Walden & Younger Corvette Restorations, Corvette Central and Street Shop to build, in essence, a 1957 Corvette with a modern twist. Titled P-57, it will have the style, feel and appearance of a slightly modified '57 but, under that gorgeously styled skin, it will be as modern as anything on the road.
In this, the first segment of a continuing story, we are starting at the frame, the base of the car, and we will be adding to that foundation until we have completed the car. Then, just like Rex, we'll be showing the car to our readers in a complete feature in Corvette Enthusiast. Unlike Rex, which was a numbers-correct project, the goal of P-57 will be to have fun, driveable car that has modern amenities with that classic styling so many Corvette enthusiasts love. Follow along and we'll get started mixing today's technology with yesterday's style.
1. The most basic element of the chassis is the frame. Street Shop starts with .120-inch (approximately 1/8") walled 2X4" square tubing which is then mandrel bent to Street Shop's specifications. One of the problems on these cars is the rear section of the frame interfering with the underside of the body. Street Shop has extensive R&D in creating a frame with a minimum of interference between the body and frame.
IN THE BEGINNING: Unlike Rex, where we had almost nothing to work with, we really did have nothing to work with on P-57. Other than a pile of square and round tubing and some discarded C4 suspension pieces, everything had to be created, and that's where Street Shop comes into the story. We wanted a solid foundation for our Corvette but we didn't even have an original frame to begin with, so Tray at Street Shop custom-built a complete rolling chassis for us that will serve as the foundation for our '57. Upon that foundation, we will be putting a Corvette Central Concept '57 body. Both chassis and body duplicate the original 1957 mounting points and hardware so the marriage should be a good one, but we'll have more on that later.
2 The frames are actually assembled in stages. The rear crosspiece is assembled in a specific jig to ensure that its measurements are correct. Also, all the welds inside the tubing are chased (ground out) before mandrel bending to ensure that the bends are always accurate and correct. The two round holes in the rear crosspiece are for the exhaust, which can accommodate a three-inch pipe with adequate clearance.

3 The front cross member is also preassembled. This is the basis for the entire front suspension. This needs to be correct or nothing else will matter.

4 The next phase of the frame-building process is to completely jig assemble the frame. This is where all the chassis mounting points are installed and checked for accuracy, as well as the frame's overall dimensions.

5 The frames are entirely MIG welded on the frame jig to prevent any distortion, and each frame is serial-numbered once it is finished.

6 The Street Shop frames are designed to use C4 suspensions, so the customer will need to locate a rebuildable chassis - or Street Shop can provide one. All the ball joints and bushings get replaced.

7 The rear suspension gets rebuilt because there are some parts that are specifically manufactured for Street Shop to make the chassis operate correctly under their frames.

8 The last phase of the frame's construction is the upper brace. This fixture checks the additional points such as the engine mounts and the body mounts to make sure they are placed correctly.

9 We wanted modern motivation, so P-57 will receive a 2004 LS6 replacement motor from Conley Smith Chevrolet in Stevenson, Alabama.
10 Tray from Street Shop is preparing to mate the LS6 engine to the Keisler Automotive Engineering-supplied Tremec TKQ-500 5-speed transmission via the Lakewood bellhousing designed for this purpose. The 5-speed will give us a lower first gear while still providing overdrive for highway cruising - and we still get to row through the gears in a classic Corvette!

11 Since we're not doing a restoration, we could take some liberties with the wheel/ tire combination. P-57 will ride on a set of American Racing Torque-Thrust Classic wheels measuring 17X7-inches front and rear. Tray reports that eight-inch wide wheels will fit but it's very tight. Kumho Ecsta 215/50-17 tires keep the ride quiet and comfy.

12 While many of the chassis components are factory GM parts, there are several pieces specific to Street Shop that make the suspension work together. Chassis components are available powder-coated or bare. While other colors are available, black is the standard color for the components.

13 Street Shop can provide either solid-axle or IRS rear ends with their frames, and Dana 36 or 44 differentials are available, but Tray emphasizes that if you are using a standard, opt for the Dana 44 differential. Also note that all the brake and fuel lines are CNC formed to ensure consistency and fit. Street Shop also uses only the 1989-and-up rear suspensions for several reasons, one being the improved and easier-to-accomodate emergency brake assembly.
The bottom line: We're not trying to mislead anyone into thinking that you could build a modern '57 Corvette for less than what you could probably find an original one, but when it's all said and done, you will have a '57 Corvette, in concept, that will include all the cues that you personally find important. In the case of P-57, it will have all the modern amenities that make driving today's cars so enjoyable, along with the design and styling that make driving a classic Corvette such a kick. With that said, let's get started.
Thanks to Corvette Enthusiast - Written by: Andy Bolig
Copyright 2006