Not to be overshadowed by the sultry skin, the Challenger's mechanical pieces are equally as impressive. Between the framerails sits a 528ci Indy Cylinder Head crate Hemi that spits out 730 hp and 660 lb-ft of torque. It's based on an Indy aluminum block bored to 4.500 inches, an Eagle 4.150-inch steel crank and rods, and Wiseco 10.25:1 pistons. Matched with a COMP 248/254-at-.050 mechanical roller cam, a Barry Grant 850-cfm carburetor, and Indy 440-cfm cylinder heads and intake manifold, the combo is both heroically nostalgic and potent. "It sounds absolutely wicked. The only appropriate motor for a Mopar is a big, naturally aspirated Hemi," Jeremy says. Moving farther rearward, the massive elephant mates to a Tremec TKO five-speed stick, which dispatches torque back to a Heidts independent rear suspension. The slick setup was originally designed by Heidts for street rods, then later adapted for muscle car applications. It's both simple and effective, and features a Ford 9-inch centersection mounted to the frame with a crossmember, 2-inch halfshafts, tubular lower control arms, aluminum spindles, QA1 coilovers, and inboard-mounted disc brakes.
The beastly Hemi has been...
The beastly Hemi has been set back as far as possible to improve weight distribution and steering rack clearance. As with the exterior, gray and black components mesh with bright red accents. A Billet Specialties serpentine belt system anchors the alternator, power steering pump, and A/C compressor.
Proving that its superb crafting skills aren't just limited to shaping sheetmetal, the Roadster Shop put on a veritable fabrication clinic beneath the car as well. Cradling the Hemi is a custom-built tubular K-member, which anchors custom control arms and aluminum spindles. A NASCAR-style splined front sway bar keeps body roll in check, and custom subframe connectors-triangulated at several points-run the length of the frame. Likewise, the exhaust system is more art than mere utilitarian piping. The elegant river of stainless steel tubing starts with custom 21/8-inch long-tube headers, which flow into 4-inch collectors and X-pipe. From there, dual 3-inch intermediate pipes tuck tightly into the trans tunnel before feeding Flowmaster mufflers, negotiating the IRS, hugging the sides of the gas tank, then merging together once again while exiting into the custom roll pan. Since band clamps and saddle clamps are just too ordinary, fancy V-band clamps join the tributaries together. "Even though this car sits very low, the exhaust is tucked in so nicely that nothing hangs less than 5 inches off the ground. This is very important, since driveabilty is a top priority," Jeremy says. "Unfortunately, it was the middle of winter when we finished this car, but we couldn't wait to drive it so we took it out anyways. It was a riot trunkin' it through the streets of Chicago during the middle of a snow storm. I can't wait for some nice summer weather so I can cruise it and run it on the autocross."
The Roadster Shop spent countless...
The Roadster Shop spent countless hours tucking the exhaust tightly into the trans tunnel. CNC-machined from thick blanks of stainless steel, even the tailpipe support brackets are works of art. To maintain the "wash and wear" appearance of the undercarriage, the stainless Rock Valley gas tank was painted black.
The Roadster Shop has proven once again that applying street rod savvy into building a muscle car yields one heck of a street machine. So why would a well-known street rod shop venture into the world of muscle cars? Jeremy says it's an escape from the stresses of building gazillion-dollar roadsters for the sole purpose of winning a trophy. "We started out as a chassis shop building frames for '32 Fords, then transitioned into building complete cars. However, indoor car shows aren't for everyone, so we're now taking on more and more muscle car projects," he says. "When it came time to build our own car, we wanted to build something that was over the top, but still completely streetable, functional, and comfortable. Personally, I have more fun building muscle cars because if you plan on running them hard, they have to be overbuilt and over-engineered to handle the rigors of abuse. As a car builder, I really enjoy that challenge."