1969 Chevrolet Nova - Track-Time Torque Arm Install

Speed Tech Performance Three Link Rear Suspension Install

At the last Super Chevy Suspension and Handling Challenge (presented by Nitto Tire), a dark horse of sorts figuratively, and some say literally galloped in. It wasn't the most powerful nor was it the lightest or most compact, but the Speed Tech Performance '69 Nova exceeded everyone's even its handlers' expectations.

The objective of the Challenge was to pit various suspension manufacturers' trophy cars against a '10 Camaro SS in various contests: slalom, skidpad, braking, etc. That Speed Tech's David beat GM's Goliath wasn't exceptional; a number of cars did. That it trounced the Camaro so soundly was. ResurreXion, as its handlers call it, behaved amazingly well in Super Chevy's battery of tests, especially considering its lack of fine tuning before the event.

We finished it on Tuesday night and loaded it into the trailer on Wednesday, Speed Tech's Blake Foster noted. The Nova bore Speed Tech's latest release, an adaptation of the torque-arm rear-suspension design that GM debuted with the '82 F-body. Basically a hybrid of the four-link and ladder bar, it preserves the best of both (the high instant center and anti-squat of a ladder bar and the articulation of a four-link) and dispenses with the worst (the bind and roll oversteer of a ladder bar and the marginal anti-squat properties of a parallel four-bar).

As good as GM's design was, its implementation wasn't flawless. The soft, oversize bushings the General employed helped the cars ride a little softer but deflected dramatically under load. Open-channel stamped arms and links kept costs down, but at a similar road-holding expense as the soft bushings.

Replacement tubular arms and hard-plastic bushings mitigate the deflection but not without consequences. Their near inability to flex causes the suspension to bind as it articulates, effectively altering the spring rate as a consequence. So extreme are the forces that they often loosen the jam nuts that prevent adjusters from rotating and wearing the threads in the arms. Speed Tech addressed these shortcomings in two ways. One is familiar: Thrust-type bearings in the middle of the lower links eliminate the bind otherwise caused by stiff tubing and solid Delrin bushings. Only these bearings aren't what you think; they're actually threaded joints.

Essentially the lower links resemble an oversize bolt and nut. That it was designed to move freely means it has no jam nuts to loosen or parts to wear prematurely when they do. To adjust a link's length, simply unbolt one end, turn it by hand and reinstall. The design's adjustment range exceeds that of a conventional rod end, and its threads' greater root diameter yield a stronger part too. Finally, permanent grease and positive seals ensure years of maintenance-free operation under potentially the most demanding environment of all: daily driving on dusty and wet roads.

How Speed Tech prevented the torque arm from binding is unique as far as we know. A Delrin bushing bolted to the forward end of the arm slides into a tube at the kit's center crossmember. The hardness that prevents the bushing from deflecting under acceleration or deceleration also prevents the suspension from compressing and rebounding if not for its shape. Its torpedo-like profile makes the bushing act like a spherical bearing, a giant one free to move in and out of the crossmember tube as the suspension compresses and rebounds.

Blake Foster and Roger Maniscalco demonstrated this freedom of articulation for this author before they installed the springs for this story. Though they lifted one side of the axle higher than its upper limit, the other side stayed well below its lower limit. This low-bind operation leaves the springs, dampers and anti-roll bars to control movement. Probably the best way to understand the suspension is to see how it mounts in a car. To do that we followed along as Foster and Maniscalco installed the one on the very Nova that proved the design's merit at the Super Chevy event.

Most notable was the kit's non-invasiveness; it requires no floor modifications and will work just as well on a car with stock wheelwells as it will on one with mini tubs. Its installation requires welding, but the extent is limited to two small sections directly over the rear axle that could easily be removed without harming the car's integrity. Though developed and tested on the '68-74 Nova platform, by dint of platform similarities it also fits '67-69 Camaros. Foster forecasts applications for second-generation Camaros and G-body cars within the year. If those designs fulfill the promise made by this one, rest assured more will follow.

1 Speed Tech's design owes much of its success to unique, maintenance-free threaded joints in the links. They let the link ends rotate rather than bind as the suspension articulates. Simply turning the end alters the link's length and as a consequence the rear-axle alignment.
1 Speed Tech's design owes much of its success to unique, maintenance-free threaded joint
2 The links' forward ends attach to the factory leaf-spring mounts. Speed Tech designed forgiveness into its brackets, a godsend as proved by the off-kilter mount on this rust-free, never-hit example. Foster corrected the gap with plain washers.
2 The links' forward ends attach to the factory leaf-spring mounts. Speed Tech designed f

3 The Nova's subframes end at the rear axle, but the spring crossmember relies on a continuous arch. The plates Speed Tech supplies weld in place but require no cutting.
3 The Nova's subframes end at the rear axle, but the spring crossmember relies on a conti
4 Foster bolted the coilover dampers to the crossmember prior to lifting it into place. Though entirely possible to install the dampers after the crossmember mounts to the chassis, he explained that the confined space under the car makes it a bit tougher.
4 Foster bolted the coilover dampers to the crossmember prior to lifting it into place. T
5 Like the plates, the spring crossmember location corresponds with existing chassis holes. It too welds in place, but its installation concludes the extent of the welding.
5 Like the plates, the spring crossmember location corresponds with existing chassis hole

6 The torque arm mounts to the axle in two locations, once at a billet aluminum pinion mount and again to tabs welded to the back of the housing. The baseline kit includes the tabs and brackets for 12-bolt and 9-inch housings, but Speed Tech's optional Strange Engineering OEM- and fabricated-style housings (shown) come fully prepared.
6 The torque arm mounts to the axle in two locations, once at a billet aluminum pinion mo
7 This Delrin bushing bolts on the end of Speed Tech's torque arm. It eliminates deflection yet its shape lets it tilt, slide, and rotate freely within the sleeve.
7 This Delrin bushing bolts on the end of Speed Tech's torque arm. It eliminates deflecti
8 Rather than into a bushing that bolts to the tailshaft, the Speed Tech torque arm slips into a sleeve in the middle of the center crossmember. That, in turn, bolts to the subframe's pickup points.
8 Rather than into a bushing that bolts to the tailshaft, the Speed Tech torque arm slips

9 The torque-arm bushing slides right into the crossmember boss but only once the axle is on a close enough plane. Roger and Blake jacked the axle into place while Gary Yorston guided the forward end in place.
9 The torque-arm bushing slides right into the crossmember boss but only once the axle is
10 For the time being, Foster hung the axle on the dampers. As future alignments require removing the dampers, he tightened their fasteners just enough to prevent them from falling out.
10 For the time being, Foster hung the axle on the dampers. As future alignments require
11 With the axle in place, the links can be pinned to the axle. As with the dampers, their fasteners were kept intentionally loose for future adjustments.
11 With the axle in place, the links can be pinned to the axle. As with the dampers, thei

12 To set alignment, Blake removed the coilovers and jacked the axle up to ride height. He centered the wheel in the housing before setting the final alignment.
12 To set alignment, Blake removed the coilovers and jacked the axle up to ride height. H
13 With the axle at ride height, Blake then measured the pinion angle. Set the pinion angle to the inverse of the tailshaft's angle. For example, if the tailshaft points down 3 degrees, the pinion should point up by the same amount. Any deviation beyond about half a degree will induce vibration.
13 With the axle at ride height, Blake then measured the pinion angle. Set the pinion ang
14 Speed Tech designed the torque arm to set the pinion angle inverse to the stock drivetrain angle. The angle is adjustable for those non-matching exceptions; simply slip washers between the arm and pinion block to rotate the axle back and increase pinion angle.
14 Speed Tech designed the torque arm to set the pinion angle inverse to the stock drivet

15 After replacing the springs, Blake installed the Panhard rod. Its initial location isn't critical, but its bearings must thread into the rod equally if it's to retain its full range of adjustment.
15 After replacing the springs, Blake installed the Panhard rod. Its initial location isn
16 Measuring with a square and tape, Blake set the axle's lateral position by rotating the Panhard rod. Left- and right-hand threads at its ends means the Panhard rod expands or contracts when rotated. Once satisfied, he snugged the fasteners and re-checked.
16 Measuring with a square and tape, Blake set the axle's lateral position by rotating th
17 The kit's adjustability means the wheels will align despite chassis deviations; the strength of its components means those wheels will stay put, even under extreme conditions.
17 The kit's adjustability means the wheels will align despite chassis deviations; the st