We can remember a time in hot rodding when suspension upgrades consisted of larger sway bars and polyurethane bushing upgrades. But, as time marched along, more widgets to make our classic Chevys handle better came on the market. Eventually, tubular control arms became available and from there the ball started rolling even faster.
Fast forward to today and the hot ticket is a complete chassis. For those that can afford the price of admission, this is the best “no compromise” way to stuff the maximum amount of performance under your Chevy. According to Roadster Shop’s Phil Gerber, “When the Chevelle was designed, performance driving, autocrossing, and driving on a road course was never even considered. If you look at a stock Chevelle frame, it’s pretty obvious it’s not capable of handling that type of driving. We weren’t happy with trying to brace the stock frame and add components that really wouldn’t give us the geometry and performance we wanted, so we created a complete frame from front to back.” The Fast Track chassis is completely TIG welded from 10-gauge slabs of steel, which are cut to shape by a state-of-the-art CNC fiber laser.
Our 1971 Chevelle wagon is heavy, really heavy, and while we had boxed sections of the stock chassis we could tell it was still flexing under hard cornering. Over the years the wagon has grown on us, plus it’s a very versatile ride since it can easily haul people and gear. Given all of this, we’ve opted to give her an extreme makeover and first on the list is adding a Roadster Shop Fast Track chassis. The extra strength will come in handy since the new engine will be a nearly 1,000hp ProCharger supercharged LS3 stroker built by the experts over at Shafiroff Racing in New York. Stopping the wagon will be left to a full complement of Baer XTR calipers along with their rear floater kit mated to a Strange 9-inch housing. The trick will be to keep the daily driver utility of the wagon while prepping it for serious track duty with parts from companies like Forgeline, Safecraft, Classic Instruments, and others.
But, much like the human body is built around a skeleton, our cars are built around a chassis. So, with that in mind let’s take a look at how the new chassis for our wagon project got started at Roadster Shop’s 30,000 square-foot facility in Mundelein, Illinois.
All Fast Track chassis are made to order, including the one for our 1971 Chevelle wagon. Our wagon rides on an El Camino chassis, so Roadster Shop (RS) was able to do the math and come up with the right 116-inch wheelbase.
The first stop for the metal that will eventually be a chassis is the Ermaksan Fibermak Gen-3 fiber laser. This is one of the larger ones in the country and extra length was needed to cut slabs of 10-gauge steel for the longest of chassis. Many chassis use bent square tube or miter cut and welded tubes to get their shape. RS handbuilds each framerail from four pieces (top, bottom, and two sides) so they can achieve any shape they want. When the pieces come out of the fiber laser they have indexing tabs. The pieces are put in jig, with the tabs interlocked, and are then tacked together.
The Fast Track chassis are fully TIG welded. This takes a lot longer than MIG, but it makes for a better looking weld that has superior penetration. The four edges of the framerails are ground smooth, but the rest of the welds are left in all of their glory. Fun fact: There’s 2,457 feet of welding (nearly a half a mile) in a typical Fast Track chassis.
While the chassis utilizes C6 Corvette spindles (which makes finding brakes and other parts insanely easy) the control arms are TIG welded based on Roadster Shop’s revised geometry numbers. When all is said and done, there are between 100 and 125 components specifically machined for the front suspension.
The chassis from Roadster Shop come fully assembled. From start to finish, it takes over 160 hours to complete a chassis with a team of around 38 people. During assembly, antiseize is applied to all of the fasteners. Fun fact: There are 450 parts in a Fast Track chassis with 420 of those parts being made in-house.
We love rack-and-pinion steering, especially when it’s on a chassis designed for it. Here our power rack is being bolted in place. There are also options for high-end upgrades, such as a slick Woodward rack.
Single-adjustable Penske coilover shocks come standard, but we upgraded to the RS Penske double-adjustable versions.
Made-to-order means RS can give you any transmission crossmember required and ours is for a TREMEC Magnum. The crossmember is designed to allow the exhaust to drop out without removing the crossmember and to allow for the exhaust to be tucked up close to the body.
The cross support for the integrated driveshaft safety loop is a nice touch and adds even more rigidity to an already stiff chassis.
The rear suspension uses a parallel four-link arrangement with extra-large bars. Knowing this is going under a rather long wagon, Phil Gerber had some tweaks made to the Panhard rod design. Roadster Shop also offers a complete IRS system that focuses on performance as much as looks.
Both the front and rear sway bars are splined setups, which helps with packaging and makes the system very tunable. The rear framerails have been narrowed and can accommodate a 12-inch wide wheel with a 345mm tire.
And here’s our completed chassis. The structural center crossmember triangulates the frame for increased rigidity. It also has front and rear torque boxes to eliminate areas where Chevelles are prone to flex. The whole deal tucks up close to the body and ends up sitting 1/2-inch closer to the rocker panel than a stock chassis.
Of course, shipping a chassis is a bit more complicated than sending small parts. Each chassis is crated up at Roadster Shop before being shipped via truck freight to the customer.
We got a bare chassis, but Roadster Shop can set things up however you want. This lucky customer is getting a C10 truck chassis with a six-speed Magnum, Mercury Racing SB4 engine, and a complete RideTech air-bag suspension. Currently, RS offers over 80 different chassis choices.
When our chassis arrived at Best of Show Coachworks in Escondido, California, we uncrated it and started getting it ready to slide under our wagon. Our plans called for a Baer floater to be added, so the Roadster Shop left the axletubes on the Strange 9-inch bare and sans flanges.
We’re suckers for beautiful welds and we were really tempted to just clear powdercoat the frame.
By designing their own arms, RS is able to make critical changes. For example, the swept back design of the lower control arms allows for a front wheel that can be up to 10 inches wide! Another option we opted for was complete stainless brake lines bent, mounted, and ready to rock. Having RS do this was cleaner and cheaper than paying to have it done later. It will also help us get this project done faster.
After blowing apart the chassis, we sent the frame off to get a medium grey powdercoat.
The suspension components were taken out and powdered a nickel color. Here you can also see the design of the lower arm, which accommodates very wide wheels.
The ball joints had to be pressed out of the arms and then pressed back in once the arms were powdercoated.
We made sure to note how the control arms are put together before blowing them apart for coating. The Delrin bushings align a certain way with the “thin” edge to the inside on both the upper and lower arms. The dog bones also have a correct and incorrect way of aligning.
As we mentioned, the Fast Track chassis uses a C6 Corvette spindle with the associated sealed bearing hub. Our wagon will be tipping the scales close to 4,500 pounds so we upgraded to the heavy-duty SKF bearing hubs.
To get the geometry just right and eliminate bumpsteer, RS uses billet steering arms designed for each chassis.
The upper shock mounts also have a certain way to mount with the spacers forward of the shock eyelets.
Here you can also spy our LS engine stands. Of course, RS can hook you up with mounts for just about any engine you can think of.
After getting all of the freshly powdercoated front suspension parts installed, we could go ahead and install the bumpstops and put the front of the chassis in the finished category.
The parts for the parallel four-link were then reassembled and installed on the chassis.
The splined bars ride on inner Delrin bushings and are held in place laterally by lock collars.
And here’s the rear sway bar completely installed. Having the splined sway bar above the frame is really clean looking, but more importantly, it frees up more space for exhaust routing.
We opted to mount our RS-Penske shock inverted since we tend to adjust rebound more often and this makes the knob easier to get to. The shock doesn’t care which way it’s mounted so the choice is up to you. Next up will be filling this chassis with a bunch of go-fast parts, including a ProCharger-boosted Shafiroff-built LS3 stroker, American Powertrain Magnum six-speed transmission, Centerforce DYAD clutch, and more.
Photos by Steven Rupp and Robert McGaffin