Install A Coilover Front Suspension
Control Freak offers an adjustable coilover and tubular control arm setup for'65-'70 Mustangs
From the July, 2012 issue of Mustang Monthly
By Dale Amy
Photography by Dale Amy
In the Mustang hobby, we are spoiled rotten by an aftermarket that is ever-expanding to meet our every conceivable parts need. Or whim. Got a front suspension in need of a little TLC? No problem; everything from stock replacement hardware to more exotic upgrades are just a phone call or web-search away--sometimes from the same vendor. Case in point is National Parts Depot, whose parts menu is perpetually expanding. And while some might think of NPD primarily as a source of factory-type components, the company's catalogs also list high-performance options such as our subject coilover front suspension setup made by Control Freak Suspensions.
The U.S.-manufactured Control Freak line of suspension products has been around for a few years now but this kit is a fairly recent addition to the NPD catalog. Aside from conversion to quickly adjustable coilovers, this particular kit banishes the factory stamped upper and lower front control arms in favor of lighter, stronger tubular-steel replacements engineered for notably improved suspension geometry. As on the'65 Shelby G.T. 350, Control Freak's upper control arms utilize lowered chassis pickup points for a greatly improved negative camber curve as the suspension compresses, keeping more tire contact patch on the pavement. They also benefit from ball-joint angles engineered to deal with lowered ride height without binding.
The recipient of our installation is a'68 390 GT owned by Harry Martyniuk, a fastback that was recently converted to a deliciously authentic Bullitt clone by Legendary Motorcar. As our photos will show, the kit was pretty much a straight bolt-in proposition, though some good-sized holes have to be drilled to relocate the upper control arm mounting points, and you'll need a spring compressor on hand to safely extract the old coils.
Aside from being host of Dream Car Garage, not to mention the head honcho at Legendary Motorcar, Peter Klutt is an experienced and nauseatingly capable road-racer, so we sought out his feedback on the effect of the Control Freak suspension mods following some before-and-after road testing. Says Peter: "As the car goes into a corner and takes a set, it feels a lot better than the original. Once it takes that set, it doesn't do anything radical as [the suspension] goes through bump or droop. Being able to adjust the shocks' compression damping also helps perfect how the car takes that initial set on cornering. The increased positive caster also makes the car more stable at high speed--it doesn't want to wander at speed."
Ours weren't the only cameras...
Ours weren't the only cameras documenting this suspension installation at Legendary Motorcar - also home to TV's weekly Dream Car Garage series - as the work was also being videotaped for a 2012 episode of the popular show.
Dream Car Garage host Peter...
Dream Car Garage host Peter Klutt drove our subject Bullitt clone before and after its suspension makeover to provide us with his impressions. Thankfully, they were favorable.
Though not covered in our...
Though not covered in our install, this GT was also fitted with Control Freak's 4-link/coil-over rear suspension and adjustable rear sway bar - the perfect complement to the coil-over front setup we installed.
Driving on urban roads, he couldn't really comment on ultimate grip, as that would have required a race track to safely quantify, but he did opine that ride quality was as good or better than stock, a result he contributed primarily to the characteristics of the kit's much higher quality dampers.
1 Control arms need to be...
1 Control arms need to be all about strength and rigidity. Control Freak's upper and lower arms utilize tubes of seamless DOM (drawn over mandrel) construction, with plate, bracket, or gusset sections that are laser cut. They are welded together on vibratory tables for complete penetration, and then powder coated for durability. Ball joint housings are CNC-machined at an angle that eliminates bind even on lowered vehicles. Fastener hardware is all Grade 8, including the supplied Nyloc nuts, and all are yellow zinc-coated for corrosion resistance.
2 The kit's machined-aluminum...
2 The kit's machined-aluminum coil-over shocks are manufactured to Control Freak's specifications by AFCO Racing. They are U.S.-made and rebuildable. Ride height is adjustable via the threaded collar on which the small end of the coil spring seats, and compression damping is quickly adjustable via a knob at the top of the shock (not visible in this photo). Note that, unlike typical coil-overs (which have a small-diameter spring mounted top and bottom to the damper unit), this kit has conical coils which at their wide (top) ends are of the same diameter, and seat in the same shock tower spring pockets as factory springs. The kit also includes new rubber spring isolators.
3 The factory upper shock...
3 The factory upper shock mounts are thin stamped steel. By comparison, the kit's powder-coated upper shock brackets are laser-cut and CNC-bent chunks of thick steel (with welded-on gussets), despite the fact that these brackets take only the damper loads, not the spring loads, which remain handled by the shock tower structure that was engineered for that purpose.
4 Typical of early Mustangs,...
4 Typical of early Mustangs, our subject '68 GT's factory front suspension architecture has the shock absorber surrounded by a coil spring atop the upper control arm. In other words, it kind of looks like a coil-over but certainly doesn't act like one due to its lack of adjustability.
5 After measuring the "before"...
5 After measuring the "before" ride height, Legendary Motorcar technician Bob Clemmens begins the teardown (we're just showing the driver's side) by disconnecting the steering linkage from the spindle using a puller.
6 With the cotter pins removed...
6 With the cotter pins removed and the top and bottom castle nuts loosened, Bob then dislodges the upper and lower ball joints from the spindle with a pickle fork. The spindle is left loosely attached for now.
7 Next, the caliper and its...
7 Next, the caliper and its sheetmetal shield are unbolted and hung aside. No need to disconnect the brake line from the caliper.
8 The sheetmetal spring "pocket,"...
8 The sheetmetal spring "pocket," or shield, with its integral rubber bump stop, is next on the removal list - a simple task of undoing six nuts that secure it to the shock tower. With the pocket out of the way, access to the upper reaches of the spring and shock is greatly improved.
9 Bob then turns his attention...
9 Bob then turns his attention to pulling the shock absorber, starting by unbolting it from its control arm bracket.
10 In the engine bay, the...
10 In the engine bay, the upper shock bracket is unbolted from the tower and the shock and bracket are pulled up and out.
11 A spring compressor is...
11 A spring compressor is then inserted through the shock tower and, once the coil is compressed, it can safely be removed.
12 With the coil gone, the...
12 With the coil gone, the previously loosened castle nuts securing the spindle to the upper and lower arms are removed and the spindle and brake rotor can be taken off as one assembly. No changes or modifications will be required for these parts - they will simply bolt back onto the new control arms once installed.
13 Bob then unbolts the sway...
13 Bob then unbolts the sway bar link and strut rod from the lower control arm, and proceeds to disconnect the arm itself from the chassis mounting point. Sharp-eyed readers familiar with '68 Mustangs may notice that the strut rod shown here is actually a '67-style straight piece, thus the extra hole in the control arm. Somewhere in its history, this particular GT had inherited a '67-style strut on the driver's side, but it still had a correct (angled) '68 strut on the passenger side.
14 Bob uses a bungee cord...
14 Bob uses a bungee cord to support the upper control arm for easier access to remove the two bolts securing it to the shock tower structure.
15 Here's a comparison of...
15 Here's a comparison of the factory upper arm and the Control Freak replacement. Notice the spring seat on the factory arm. On the coil-over setup, the new spring will instead seat on a threaded ring on the new damper itself, thus providing easy ride height adjustment.
16 Before the new upper arms...
16 Before the new upper arms go on, a provided template temporarily bolts to the old mounting holes to allow marking for new lower mounting holes that will have to be drilled. This is, of course, what Shelby did on the '65 G.T. 350 to improve its front suspension geometry for better handling. Lowering the inner pivot point of the control arm provides both a better camber curve as the suspension compresses, as well as more positive caster for improved steering feel.
17 A supplied spacer goes...
17 A supplied spacer goes between the inboard end of the control arm and the shock tower.
18 Here you can see the position...
18 Here you can see the position of the newly installed upper arm in relation to the factory mounting holes for the old arm. The new arm mounts about 1.25 inches lower.
19 The new lower arm simply...
19 The new lower arm simply bolts to the original inner mounting point, then the spindle/rotor assembly can be loosely secured to the upper and lower ball joints.
20 Now the various components...
20 Now the various components of the coil-over assembly go together and you end up with something like this. The narrow-diameter bottom of the conical spring sits on the shock's threaded collar for height adjustment. But note that, unlike most coil-overs, the wide upper end of the Control Freak spring does not mount to the shock body. It will instead tuck into the same spring pocket at the top of the shock tower as the factory spring did (note the new rubber isolator supplied).
21 The coil-over assembly...
21 The coil-over assembly is maneuvered up into the shock tower after removing the old, worn out rubber spring isolator. The lower T-bar bracket is secured to the upper control arm.
22 Note that the coil-over's...
22 Note that the coil-over's lower T-bar bracket mounts to the underside of the control arm, not on top (unless for some reason you're wanting to dramatically raise your front ride height). In this shot, the sheetmetal spring shield has also been bolted back in place.
23 Up top, the beefy new...
23 Up top, the beefy new shock brackets go in place to secure the top of the coil-over damper. This shot also shows the shock's easily accessible knob for adjusting compression damping.
24 Prior to heading off for...
24 Prior to heading off for an alignment, the trial and error process of setting ride height is accomplished by rotating the coilover's threaded collar clockwise. Spraying some lube on the coil-over body's thread eases the task. No tool was included, so we just used a large punch inserted into the holes in the collar to facilitate the turning. The collar position shown is where we ended up for our particular car's 215/70R15 tires. As they say, your results may vary...
25 Harry Martyniuk's '68 GT served as our test victim (after having been converted to a faithful Bullitt clone by Legendary Motorcar - right down to the body-colored side mirror and rocker trim of the movie's star car). This is its menacing stance after fitment of the Control Freak suspension hardware.
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