We’ve all been there before. Projects that take so long to get done that the parts on it, which were once the “latest and greatest,” have become surpassed by newer designs. Well, that’s our world, too. Our 1968 Camaro, Project Track Rat, has been moving along at a snail’s pace and after we assembled and installed the Chassisworks front subframe the wizards over there came out with some new, really cool stuff for it. Since our Camaro is waiting for its RHS block to come back from the machine shop we had the time and tools to bolt on this new suspension tech.
What Chassisworks did was start from a clean sheet of paper and completely redesign the spindles and control arms used on their g-Machine and StreetMachine crossmember systems. The polymer pivot bearings and cross-braced tubular design makes for crisp, sharp handling due to its resistance to deflection. The wide-track control arms are rigid, but more importantly, Chassisworks reworked the geometry for better handling while keeping the same wheelbase. They also incorporated a sealed bearing, so no more packing grease, but they didn’t go the easier route by using a GM piece and instead designed their own. The change in shape to the arms also accommodates much wider wheel and tire combinations.
In short, they figured out how to shove more suspension performance under your Chevy, and the ability to run larger rollers is a big plus in these days of 315mm, or wider, front rubber.
1. There’s no other way to describe the Chassisworks gStreet uprights other than badass. The gStreet system is engineered to work with Chassisworks’ bolt-on clips and their weld-in suspension crossmembers. The lightweight billet-aluminum upright incorporates a heavy-duty, sealed unit bearing that is larger in diameter and, according to Chassisworks, considerably stronger than the Corvette bearings typically used. The spindle has a corrosion-resistant nickel plating and the sealed bearing itself is maintenance free.
2. The upper arm pivot is housed within the billet upright. Removing the billet cap allows access for adjusting the tension on the spherical pivot to compensate for wear. The upper pivot comes factory-assembled with the correct amount of preload adjustment already done.
3. The steering arms are cross-bolted to the billet upright and utilize a locating pin feature.
4. Here you can see the gStreet upper control arm on the left and the g-Machine arm on the right. The gStreet system uses the same chassis mounts as the g-Machine arms, so upgrading is easy. The arm length was increased 1.5 inches to provide more gradual geometry changes throughout suspension travel, resulting in better tire feedback to the driver. According to Chassisworks, these engineering changes results in reduced scrub radius, better camber gain, and increased caster. All of this without changing the wheelbase. The main body is 1-inch tubular, TIG welded steel while the crossbrace comes in at 7/8-inch diameter. For added strength, the A-arm pivot stud receiver is billet steel. Camber and caster adjustments are made by turning the adjustment couplers, so no shims are needed.
5. Here you can see the huge differences between the g-Machine lower control arm on the left and the g-Street arm on the right. The main body is mandrel-bent 1.25-inch TIG welded steel while the crossbrace is 1-inch diameter steel. Chassisworks also drastically changed the shape of the lower arms, which increased how wide of a tire; potentially up to 335mm wide; you can run on the front and still have a good turning radius.
6. The lower arm pivot is similar to the upper, but is contained within the arm. It’s adjustable to ensure zero free-play and still have minimal resistance. Like the upper, it’s fully rebuildable.
7. The new gStreet arms bolted right up to our Chassisworks subframe using the same stainless hardware. The control arms, upper and lower, use low-friction polymer pivot bearings.
8. Of course, before inserting the stainless fasteners we made sure to hit them with some antiseize coating.
9. The new lower arm bolted to subframe in place of the g-Machine arm. Here you can also see the billet steel arms of Chassiswork’s new adjustable-rate, gun-drilled lightweight sway bar system.
10. The kit comes with the needed hardware for installation and the gold Grade 8 nuts are used for assembly only. Once together, the black, single use locknuts secure everything in place. The 9/16-inch nut is torqued to 130 ft-lb while the upper 1/2-inch nut is torqued to 90 ft-lb of torque. A 1/4-inch Allen wrench can be used, if needed, to keep the pivot studs from spinning.
11. The lower pivot stud is an interference fit to the spindle. This requires heating the upright to expand the bore diameter. The first thing we did was to make sure the pivot stud and the bore was free of any debris that could cause a problem. To ensure an accurate temperature reading during the heating process we painted a small area flat black. This is critical when using an infrared thermometer.
12. We used a heavy-duty heat gun—or you could use a torch—to warm up the spindle bore to between 325 and 350 degrees. Be careful if you use a torch since temps over 400 degrees could damage the spindle. Also, don’t put the upright in the oven since the high temperature could damage other parts of the assembly.
13. Once up to temperature the next few steps had to be done quickly before the upright cooled back down. We dabbed some antiseize on the pivot stud, inserted it through the spindle bore, installed the flat washer, and then the nut (be careful, it’s hot). The hex nut was tightened until the stud flange was seated tightly against the bottom of the upright. If the pivot stud tries to turn you can use a 1/4-inch Allen wrench to hold it in place.
14. Once everything was secure and cooled down we removed the Grade 8 nut and installed the locking nut. The upper arm was installed the same way, but no heat was needed.
15. The gStreet infinitely adjustable bumpsteer kit (PN 5736-75-56) is another cool product we upgraded to. It uses a Teflon-lined 4130 rod end and a unique 3/4-inch threaded stud, with locknut, to allow the pivot point to be quickly adjusted without disassembly or messing with shim stacks.
16. Here’s the adjustable bumpsteer kit full assembled with the steel adjusting sleeve. The locking jam nut on top is used to determine the height and the bottom is locked down by a 12-point flanged locknut. Once on the road we should be able to completely dial-out any bumpsteer.
17. And here’s the passenger-side gStreet system fully installed along with the adjustable bumpsteer kit and the gun-drilled, splined, sway bar. We’re still building the rat, so for now we’re using a bar in place of a shock.
18. Eventually we’ll be installing these double-adjustable VariShock QuickSet-2 coilovers. They feature sophisticated shock valving with all-new, American-made components. One knob sets bump (compression) while the other sets rebound (extension). Internally, they have Deflective Disk Valving to eliminate spring fatigue and the piston rods are made from 5/8-inch centerless-ground, hard-chrome steel. The design of the lower ring doesn’t require a locking ring, instead it’s secured in place by two ball locks that press into the grooves on the reservoir body. Our starting point for testing will be 2.5-inch ID, 9-inch long, 550-pound VariSprings.
19. The spindle has an integrated caliper mount that can accept calipers from either Wilwood or Baer. The gStreet kit was designed to use either 14- or 15-inch rotors.
20. Our brake kit came with 15-inch (1.25-inches thick) rotors and massive Wilwood Aero6 nickel-coated six-piston calipers with ThermLock pistons, which blocks heat transfer from the pads to the fluid. The hats are Chassisworks pieces but the rotors are off-the-shelf Wilwood parts so replacements are easy to get. Now to get this Chevy on the road before the next new part hits the market!