You may remember this article in Hot Rod a few years back when Corky Bell of Cartech headed up a re-designed Cobra replica project.
Below text is from Hot Rod.
"His original idea was to sell turnkey Cobra kit cars, but then Corky Bell thought, Why work with someone else's kit when you can build your own? And why not build the best Cobra in the world? Rather than stuffing a big V-8 into a cute-but-archaic '50s sports car like Shelby did, Bell set out to scratch-build a serious high-tech, high-powered, rear-transaxle sports car with even more power than the big-block, all stuffed under a composite 427 Cobra body. If Shelby's car is a Cobra, then Bell's should be called the Mongoose.
Bell's engineering career began in the early '70s at Bell Helicopter (no relation). His side business, Japanese GT Cars, funded his SCCA road-racing habit, and he went on to build turbo kits and intercoolers for sports cars, ponycars, and sport compacts under the Cartech brand name. By the early '90s, the annual revenue of his Bell Experimental Group Inc. (BEGi) topped $1 million.
Companies like Kirkum Brothers already make highly accurate Cobra replicas, and ERA and Superformance produce Cobra-like cars with nicer interiors, stiffer frames, and improved suspensions for about $75-90K. Factory Five has the best working-man's package based on 5.0 Mustang components. However, none packaged the entirely new sports car Bell wanted underneath the classic Cobra body. Furthermore, it didn't take too many sightings of NBA players in full-bling Escalades to make Bell think there might be a market for a sports car that tall guys could actually fit in. To make it all work with a stock 427 Cobra body and wheelbase would require a transaxle at the rear and an asymmetrical layout.
Over the years Bell made a lot of friends, and when he got serious about car building, he brought them into the Mongoose Project. Included in the group was enthusiast-investor Charles Nearburg, a Texas oil man, car collector, and former IndyCar racer who had the critical financial resources to fund the development of the prototype CB1. Also involved was Ron Nash, a buddy with a degree in physics who, before he dropped out of the car scene to became a full-time veterinarian in the '90s, designed front-engine, rear-drive, competition road-race suspensions for Newman and Sharps' Nissans, Jack Roush's first season Merkurs, and Buick's late-'80s Trans-Am racers. Nash came back to design the suspension for Bell's Mongoose. Other top-notch pros involved include Peter Schwartz (stress analysis), Todd Gartshore (marketing savvy), Bob Salzman (aesthetics), Trey Hermann (designer and stylist), and Ford drag racer Chip Havemann (attorney).
The birthing site for the CB1 Super Cobra was a private airport 30 miles northwest of San Antonio, Texas. In the winter of 2002, Bell and his team constructed a precision alloy platform on rollers, which they used to construct the prototype frame. "We had to bring together the tires, engine, transaxle, and seat then play with the layout," says Bell. "Getting all those parts in the position you want dictates where the suspension will be and where it will pivot, which, in part, dictates where the frame has to go. With those dimensions worked out, I went on paper to draw the frame."
Note that he did not use CAD software to design the prototype. According to Bell, "When you're trying to optimize space, you've got to make judgments, like how close you can get the frame to the engine and still get it out. To compile space for the driver, we were scraping for an eighth of an inch at a time. If we could do that eight times, we had an inch. I don't think you can do it with a computer."
The Mongoose came to life over the next nine months, designed around a space frame of 2-inch-square tubing. The design allowed seats to rest directly on the floor of the car rather than atop the frame like a Shelby, which provided extra inches of height for big drivers.
The engine is an early 351 Windsor that could be punched out to nearly 427 ci, a nice selling point (though it displaces 385 cubes in the prototype). Trey Hermann sketched out a turbo-EFI upper intake manifold for the 351 to fit under the Cobra bodywork, and Bell made the casting. The rear transaxle solved a lot of problems-it's a Porsche G50/50 in the prototype, running upside down and backward. You can't have a central space frame and a conventional transmission without greatly intruding on the driver and passenger. The G50/50 opened up space, though Bell used some of it for a stiffer frame and the torque tube. The remote shifter solved certain ergonomic issues related to the rearward location of the engine. Using the transaxle, Bell's team managed to put 57 percent of the weight at the rear of the car.
The Bell team labored to perfect everything, from the rigid engine-to-rear-transaxle torque-tube design to the door hinges, which were unexpectedly difficult to refine. They created molds and cast 11 special parts for the Mongoose. High points included jacking up the car and feeling the remote shifter snick into all six gears on the first attempt, and the moment Bell turned the key and the Mongoose started up and just drove away with zero problems. Strapped to the Dynojet chassis dynamometer, the twin-turbo 351 ripped off a 505 rear-wheel horsepower run at just 7.5 psi boost.
Eventually, the entire Mongoose team assembled at the Motorsport Ranch test track south of Fort Worth, Texas, to kick the tires and light the fires, and there came the sublime moment when Charles Nearburg drove into the pits from the maiden flog, stepped out of the car, and pronounced it a "marvelous machine that drives a gnat's ass from perfect." The only consequential change would be to modify the front frame to lower the ride height.
"I think everything with the exception of the torque tube can be a production design," says Bell. "But everything will change a little bit. We're going to use the same basic suspension-upright casting patterns to build the production pieces, but we may fatten up a little bit here, lighten up a little bit there, or make the steering arms slightly longer or shorter, but they'll be the same basic pattern."
The planned production of 12 to 15 cars a year will require new capital from here on. "We'll need tool-up assistance and money," says Bell. "We have a frame designed for the first prototype, and it will closely approximate the next one. We have suspension members, and we'll start doing a stress analysis on those. By the time the next car is done, we should also have a stiffness analysis."
www.bellengineering.net.
Powertrain Engine: The '73 385ci Ford Windsor engine is equipped with Canfield aluminum cylinder heads, JE 8.5:1 forged pistons, an Eagle steel crankshaft and rods, and a BEGi EFI turbo upper intake manifold. It was assembled and machined by BEGi. Forced-induction power enhancement comes from a TIG-welded stainless steel hot-side turbo system using Garrett T4 turbos and Tial wastegates providing 0.5-1.0 BAR boost on 93-octane pump gas using Electromotive TEC III engine management. The camshaft and gear are by Crower. The radiator is a Ron Davis custom piece. The CB1's twin side pipes use 3-inch mandrel-bent Burns Stainless tubing and mufflers. The fuel system uses twin Pierburg fuel pumps, a TWM regulator, and 52 lb/hr fuel injectors. Ignition comes from four Electromotive wastespark direct-fire coil packs.
Power: It makes 505 hp and 540 lb-ft of torque at the rear wheels at 7.5 psi of boost measured on Henderson Performance Technologies' (New Braunfels, Texas) Dynojet chassis dynamometer.
Transmission/Transaxle: It's a modified Porsche G50/50 five-speed transaxle with a Porsche limited-slip differential and 2.5:1 final drive ratio and a remote BEGi shifter and ball-bearing U-joint-based shift linkage. The engine has a single-disc Centerforce clutch, pressure plate, and flywheel and is connected to the transaxle with a custom torque-tube and driveshaft.
Chassis
Frame: Monocoque-reinforced 1018/1020 alloy TIG-welded steel central backbone space frame.
Suspension: Front independent struts are located by double wishbones, with Aldan coilovers and antiroll bar. Rear independents are located by double wishbones with toe-control links and Aldan coilovers.
Brakes: Baer four-piston calipers with 13.0x1.25-inch vented front discs and 13.0x1.125-inch vented rear discs.
Wheels: The fronts are 17x9.5 and the rears are 17x11, all from Team Three.
Tires: BFG G-Force TAs, with 245/40ZRs up front and 275/40ZRs at the rear.
Style
Body: Composite 427 Cobra from Antiques and Collectibles.
Paint: The CB1 was sprayed Bright Yellow basecoat/clearcoat in acrylic urethane by Darrell Connell at Trevcon in San Antonio, Texas.
Interior: BEGi created the custom bucket seats. A complete Simpson five-point racing harness and Auto Meter Sport-Comp gauges (for speedo, tach, fuel level, coolant temperature, volts, boost, oil pressure, oil temperature, transmission temperature, and clock) make the interior comfortable but serious."
http://www.hotrod.com/featuredvehicl...bra/index.html
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