A few short years ago, The Roadster Shop realized the potential of a purpose-built musclecar chassis after spending years in the street rod market. The company actually decided to found a separate division (under the same roof) to market the product, and called it RS Performance.
After searching out a musclecar make and model that would hopefully appeal to the masses, RS Performance decided on a chassis for '64-72 Chevelles, a choice made after looking at a few factors in the marketplace:
1) Popularity. Who doesn't want to drive a Chevelle? Just about any of the body styles are timeless, and nothing shouts musclecar at a local drive-in louder than an A-body.
2) Relative availability. There are tons of them out there, from old, granny-driven '66s, on up to '72 Super Sports.
3) Original frame/suspension shortcomings. Let's face it, A-bodies are absolute slouches in the corners, and on the highways and byways around town for that matter. They handle like a two-year-old on a tricycle, plowing into things, sliding all over the place. This factor left RS Performance plenty of room to improve with its new design.
Says Phil Gerber of RS Performance, "There are three different year ranges for the Chevelle chassis: 1964-65 are the same, 1966-67 are the same, and 1968-72 are the same. The main difference is in the front and rear frame horns where they meet the bumpers. We build a specific chassis for each year. We also do the chassis for every model-hardtop, post, convertible, wagon, and El Camino."
The test mule for the chassis, the car that appears in these pages, was snatched up as a 60,000-mile, numbers-matching 1966 that was, it turns out, a grandma car, probably never taken up to the stratosphere of even 4,500 rpm. The build actually started out harmlessly: Jeremy Gerber, along with dad Neil and brother Phil, and a host of other Roadster Shop employees, originally planned for this to be a direct swap of the RS Performance Chevelle chassis-in with the new, out with the old, and the hulk of the original car would stay the same as it was. However, after further deliberations, the decision was made to turn this car into a true R&D machine, with a fully custom powertrain and killer exterior looks (not to mention the prototype chassis and suspension setup under the skin).
The build took just seven months, and the Chevelle now packs a Bill Mitchell Hardcore Racing aluminum 540 big-block, with an Eagle rotating assembly, Mahle pistons, and World Products Merlin aluminum heads and solid-lifter camshaft. A single Hardcore 1050-cfm 4-barrel and Merlin X single plane intake cap things off. With a pump gas-friendly 10:1 compression ratio, the lightweight rat makes an advertised 685 horsepower and 685 lb-ft of torque.
Obviously, power is great, but when dealing with G-Machines and Pro Touring circles, it's equally (if not more) important that the car handle and stop. For its Chevelle chassis, RS Performance has spared no expense, while keeping the price tag on the affordable side. The RS Performance chassis, which starts at $15,495, includes just about everything you could want to make a Chevelle handle some of the most aggressive, twisty roads out there. To start, the front end carries a jointly developed Detroit Speed and Engineering/RS Performance-modified C6 Corvette spindle setup, with Afco remote-reservoir double-adjustable coilovers, tuned specifically to the application (in this case, the '66 test mule). There's also a splined sway bar that definitely helps with body roll.
The rear is a four-link designed by RS Performance, with QA1 adjustable coilovers, and heim-jointed rod ends. The rear also packs a Ford 9-inch with heavy-duty 31-spline axles, designed to withstand massive amounts of loading. The frame itself is narrowed at the rear, in the expectation that customers will go wild with rubber, and can accept up to a 14-inch-wide rear tire.
With all this potential grip and nearly 700 horsepower, brakes and tires are critical. Wilwood 14-inch drilled and slotted rotors reside at all four corners, with 6-piston calipers in front and 4-piston calipers in back. While some would have snuckk in barely DOT-legal road race rubber to improve the track times, RS Performance went with Michelin Pilot Sport SP2 tires-high end sports car tires to be sure, but they are full-depth skins with a street compound. They measure 255/35R19 and 335/30R20 (fore and aft) and encircle 19x9 and 20x12-inch Boze alloy wheels.
To be able to go find some grocery-getter Chevelle (the chassis fits all models up to 1972), and throw this amazing example of fine engineering at it, is just awesome. We're talking a 3,500-pound car that would probably out-handle a Corvette.
To see if that hypothesis is true (unfortunately without the Corvette side-by-side comparo), we tested out the vehicle at Autobahn Country Club Joliet, just outside of Chicago. The 2.04-mile South Course happened to be a more than adequate proving ground for the Chevelle, which had seen very little aggressive throttle use, much less heavy loads under cornering. We strapped into the Cobra seats, mated to Corbeau four-point harnesses that keep the upper torso pinned to the shoulder bolsters of the awesome buckets, and prepared to literally beat the hell out of the car.
After turning on the master power switch and the fuel pump, a press of the big red button labeled "Start Engine" brought the horses from the Hardcore Racing 540 big-block to life. A slow jaunt around the track-to throw some heat into everything and to get a feel for the sightlines in the 14 turns-helped familiarize us with the Master Control paddle shifters, and also helped in learning to flick the paddle-shift unit a few times to understand the inner workings of that unit. The steering wheel-mounted shifters are mated to a 4L65E semi-auto transmission, which handles even the hardest upshifts with aplomb.
Autobahn's South Course represents all types of corners-from off-camber, slow-as-a-sermon, patient, increasing radius turns to if-you-have-the-balls, uphill braking entry, flat-out exit, long sweepers that will cause a certain muscle to tense up, even in the most experienced driver. Remarkably, the Chevelle was up to the task, and then some: the car handled absolutely flawlessly for a 3,500-pound-plus vehicle (not really that remarkable, considering that we expected nothing less from The Roadster Shop/RS Performance in terms of chassis and suspension).
Furthermore, from all exterior vantage points, no single person watching yours truly hustle the Chevelle around witnessed any signs of body roll (when traveling in excess of 120 mph, you tend to not notice much else but the 90 right hander rapidly approaching). Even some of Autobahn CC's members on hand for lapping noticed how planted the car seemed, and were gawking at the car all day long.
Another interesting facet to the car was its behavior on corner entry and exit. With such a heavy front end, we expected the car to push on entry, and had planned lots of trail braking to induce some rotation at the beginning phase of the corner. However, on the first hard lap, there appeared to be very little, if any, understeer-quite a pleasant surprise. At exit, if there was even the slightest signal of a push, it was nothing the car couldn't correct with a little throttle.
But we weren't done yet. Two weeks later the car arrived at our West Coast test facility in Southern California, where we subjected it to our battery of braking, slalom and skid pad tests. Once again, the Chevelle left us with nothing but smiles. It pulled .98g on the skidpad, stopped from 60-ft in a scant 117 feet and ran our 420-ft slalom in 5.76-seconds, which equals 49.71 mph. This is the fastest slalom time we've ever recorded.
In summary, the car represents the best offerings in the aftermarket, in terms of driveability and performance combined. The chassis/suspension combo is absolutely one of the finest we have ever encountered, and should be absolute dynamite on the market.
With the current trend in Bow Tie customizations veering into the G-Machine/Pro Touring realm, RS Performance is poised to shake things up with its Chevelle chassis and suspension for A-body monsters.