No, it’s not a late-model Corvette. Thanks to the chassis wizards at Detroit Speed & Engin
Aluminum is some peculiar stuff. On one hand, it's the most abundant metal on the earth's surface, and the third most abundant element on the planet. When cast into engine blocks or cylinder heads, however, it suddenly becomes a very exotic material that commands a premium price. This may seem out of whack, but despite its abundance, extracting aluminum from ore is an extremely labor intensive and costly process. Not surprisingly, with the exception of a few common engine and driveline components, aluminum is used very sparingly at the OE level and just about never in the aftermarket. That's why the hot rodding world gasped in shock last summer when Detroit Speed & Engineering pulled the wraps off its all-new aluminum front suspension system for '64-70 Ford Mustangs. With all the buzz this hot new setup has generated in recent months, the big question is whether or not the new Aluma-Frame lives up to the hype.
Early indications suggest a resounding "hell yes!" but you don't have to take our word for it. On its maiden trip through the Goodguys autocross at the 2012 Nashville Nationals, DSE's Aluma-Frame–equipped '66 Mustang took the win in the Pro Class. Likewise, the DSE Mustang won PHR's inaugural Muscle Car of the Year competition, posting the quickest autocross times of the event while beating down some of the meanest Pro Touring rides in the country. As track results prove, when the road starts winding, the Aluma-Frame flat out gets the job done. The slick setup replaces the factory steel front suspension cradle with an all-aluminum unit matched with tubular control arms, aluminum spindles, coilovers, a heavy-duty splined sway bar, and a rack-and-pinion steering rack. Furthermore, by building the suspension from scratch instead of modifying stock hardware, Detroit Speed was able to revise the suspension geometry to optimize the camber curve, ride height, suspension travel, Ackerman angle, and static camber and caster.
The brainchild of two former GM engineers—Kyle and Stacy Tucker—Detroit Speed has established a reputation for building track-honed suspension hardware for the General's most popular muscle cars. While the company has a stable full of Camaro and Chevelle development vehicles in-house, the Aluma-Frame represents its first foray into the Ford market. Nevertheless, the Detroit Speed crew are hot rodders first, and brand loyalists second, so they approached the R&D process of the Mustang no differently than any other engineering challenge. After assessing the strengths and weaknesses of the Mustang chassis, they concluded that the factory front suspension offered few redeeming qualities and required a complete clean-sheet redesign. "The '64-70 Mustangs have very little structure to them. With a very poor foundation like this that flexes around a lot, the suspension can't do its job and you end up with poor ride quality and handling," Stacy explains.
Realizing from the get-go that they had their work cut out for them, DSE combined their engineering and racing know-how to tackle the problem. "The first thing you need when designing a suspension is a solid structure and good geometry, and these Mustangs have neither. Since we didn't want to make any compromises in suspension geometry or maximum tire size, it made the most sense to design an all-new suspension," Stacy says. "A big advantage of this approach is that you're not limited by the stock suspension architecture. With a clean-sheet design, you can set goals for camber gain, caster, geometry, suspension pickup points, and steering independently of the factory suspension packaging constraints."
Interestingly, some of the Mustang's fundamental chassis flaws are what inspired the DSE team to come up with such a creative and exotic solution. "Since Mustangs don't have a full subframe, hitting our strength targets required adding lots of structure, which would have also added lots of weight. Consequently, we tapped into our OEM engineering experience to design a cast-aluminum suspension cradle that substantially increased strength without a weight penalty," Stacy says. Furthermore, an outstanding strength-to-weight ratio wasn't the only advantage to opting for aluminum. "By nature, the casting process is more precise and repeatable than bending suspension components from steel. We machine the Aluma-Frame cradles in-house using very precise CNC equipment to ensure the mount locations and bolt holes are exactly where they need to be. Why rely on old technology when you can take advantage of the latest technology at your disposal?"
With the staggering improvements in suspension geometry and handling that the Aluma-Frame offers, those with sharp inferential skills have probably already figured out that it isn't your typical bolt-in-and-go suspension system. Truth be told, installing it does require a moderate amount of fabrication skill to cut out the factory shock towers and trim bits and pieces of the framerails. Nevertheless, any DIYer with basic welding ability should be able to pull off the install over a weekend, and considering the performance payoff that awaits, we're sure many hot rodders will decide that it's well worth the effort. To give you a better idea of what's involved, we followed along as Detroit Speed installed the very first Aluma-Frame in their '66 Mustang test car. If an aluminum front suspension isn't exciting enough for you, four-links, mini-tub kits, and subframe connectors are also on the way, so Mustang fans have plenty of reasons to celebrate.
The Detroit Speed Mustang Aluma-Frame (PN 032050) fits all '64-70 Mustangs and includes an aluminum suspension cradle, twin A-arms, forged spindles, coilovers, a splined sway bar, and a rack-and-pinion steering rack for $6,500. The standard system includes a set of high-performance shocks with DSE's own valving specs, but single-adjustable ($450), double-adjustable ($999), and remote reservoir ($1,300) units are available as well.
Detroit Speed’s Mustang was already stripped down before the install process began, but needless to say, anyone with a running Mustang will need to remove the engine and trans, along with the front suspension and subframe assembly. After disassembly, note that the rear lower control arm bolthole will be reused by the Aluma-Frame, so both the bolthole and its reinforcement flange must be retained. Before making any cuts around the shock tower, it’s a good idea to mark around the bolthole to make sure it’s not inadvertently cut off. It doesn't matter which shock tower is cut first, but DSE elected to start at the driver side.
Although it looks intimidating, cutting out the shock tower is very straightforward. Using a cutoff wheel, DSE recommends first cutting around the lower control arm mount, then working upward to the top of the tower. The factory seam between shock tower and inner fender serves as a handy cut line to assist with the process.
The shock tower, lower control arm mount, and engine mount sections detach as a single unit. Afterward, cut any remaining sections of the shock tower flush to the framerail. Removing the shock tower will also reveal several reinforcement flanges attached with spot welds, which must be drilled out. After detaching the flanges with a chisel, grind and deburr any sharp edges that remain. With the cuts on the driver side complete, repeat the process on the passenger-side shock tower.
The Aluma-Frame cradle attaches to the framerail using five bolts per side. This requires drilling four additional boltholes into the driver and passenger side of the framerail. To establish the hole locations, mock the Aluma-Frame into position by lining up the existing factory lower control arm bolthole on the framerail to the third bolthole (from the front) on the cradle. Bolt the Aluma-Frame to the framerails, and then check that the assembly is parallel to the rockers using a tape measure and a straightedge. Next, mark the holes with a transfer punch and hammer.
On later-year Mustangs, there may be some interference between the front edge of the Aluma-Frame and the factory crossbrace that ties the framerails to the radiator core support. Mark this area with a marker, and trim back the bracing with a cutoff wheel if necessary.
With the Aluma-Frame removed, locate the punch marks and drill ⅛-inch pilot holes before repeating the process with a larger ¼-inch drill bit. The hole closest to the front of the car requires cutting through a small section of the factory reinforcement flange with a 1.5-inch hole saw. The goal is to cut through the flange without cutting into the framerail. Next, cut into the framerail using a ¾-inch hole saw and remove the cut section of the factory flange with a chisel.
While the second hole from the front can be drilled using the same ¾-inch hole saw, the two holes closest to the rear of the frame require a larger 1.375-inch hole saw. The location of the rear-most hole will create interference with the stock steering box bolthole, but since it won’t be reused it’s OK to cut through it. When cutting through the sloped sections of framerail, hold the drill as close to vertical as possible.
After mocking the Aluma-Frame back into position, drill pilot holes from the bottom of the framerail to the top of the framerail using the supplied drill guide. Next, finish drilling the four crush tube holes from the top side of the framerail using a ¾-inch hole saw.
The Aluma-Frame uses a billet steel adapter plate that bolts to the top of the framerail, and serves as a support structure for the upper control arms and coilovers. To enhance the rigidity of the framerails, DSE includes four crush tubes (per side) that slide into the framerails.
Insert the crush tubes into the bottom side of the framerail, then screw them into threads in the upper adapter plate. A DSE spanner wrench is included with the Aluma-Frame system to make tightening the tubes a breeze. Next, stitch and plug weld the crush tubes to the framerail.
The upper adapter plate bolts to the framerail using supplied Grade 8 hardware. After bolting it down, locate the upper coilover mounting hole and use a transfer punch to mark its spot on the upper framerail. Afterward, remove the adapter plate, drill out the marked location with a ¾-inch hole saw, insert the coilover mount crush tube, and weld it in place from the bottom side of the framerail. Finally, reinstall the adapter plate before welding it to the framerail.
With the bulk of the cutting and welding complete, it’s time to start assembling the suspension. Secure the Aluma-Frame to the chassis using the supplied hardware, then install the lower control arms. The Aluma-Frame system includes bumpstops that function as progressive-rate springs should the suspension ever bottom out. It welds to the outboard side of the framerail, and locating it involves compressing the control arm upward and aligning it to the bumpstop pad on the control arm. Mark the corresponding location on the framerail, and weld the bumpstop bracket in place.
The Aluma-Frame system replaces the mushy factory steering box with an ultraprecise DSE rack-and-pinion unit. It secures to the frame using two Grade 8 bolts and some isolating washers to reduce vibration.
After installing the steering rack, slide the sway bar and Delrin bushings into the front of the Aluma-Frame assembly. To properly square up the bar, make sure that it protrudes 2.8 inches from the bushing on each side, then install the split-lock collars to prevent any side-to-side movement. Next, slide the sway bar arms over the splined section of the sway bar before bolting the endlinks to the lower control arms.
The upper control arm bracket bolts to the framerail adapter plate using a pair of shims stacked between it and the adapter. The bracket features slotted holes, which enable it to slide forward and rearward for easy caster adjustment. DSE recommends setting the proprietary Speed-Lign adjusters in the center groove for a nominal caster setting of zero.
Installing the coilover assembly is as easy as bolting the shock eyelets to the lower control arm on the bottom, and the upper control arm bracket on the top. By offering 6 inches of suspension travel in addition to a rock-solid cradle, Aluma-Frame–equipped Mustangs promise outstanding ride quality and handling.
Like the control arm bracket, the upper control arms also use DSE’s Speed-Lign system for simple camber changes. For baseline tuning, DSE recommends setting the adjuster in the first outboard groove for a nominal camber setting of ⅛ inch. When sliding the control arms into the bracket, they may require a gentle tap from a mallet.
Located at mounting points for the upper control arms and the upper control arm brackets, DSE’s Speed-Lign system makes on-track camber and caster tuning a reality. With this slick arrangement, the bolts are located by washers that look like ninja stars to ensure that once alignment is set, it doesn’t move around.
After bolting the spindle onto the ball joint, thread the tie-rod ends 1-inch deep into the steering rack. Finally, insert the outer tie-rod end onto the steering arm, and tighten down the castle nut before installing the cotter pin.