In our October 2013 issue we installed a killer Heidts Pro G independent rear suspension (IRS) into a clean 1956 Bel Air. The IRS not only looks cool and exotic, it actually functions—and functions well. It works so well, in fact, the front stuff became subpar. We want to use the '56 for autocross events and aggressive driving in general, so the front needed to be brought up to speed. Since we were happy with the rear fitment and performance, we decided to stay with Heidts and gather what it had for the front.
What we ordered was a complete coilover conversion that features a forged two-inch drop spindle and narrowed set of tubular arms with added positive caster. To further improve the handling capabilities, we opted for the 1-inch sway bar option. The narrowed arms (5/8-inch per side) will help us with tire clearance, the sway bar will keep the body flat, and the added caster will help with straight-line stability and quicken turn in.
More about caster on the Tri-Fives: These cars were built with an undesirable amount of negative caster at the factory, so Heidts moves and angles the ball joint to allow for up to 3-degrees of positive caster. Since the new arms use an adjustable coilover shock and spring configuration, ride height, shock settings, and spring rate changes are simplified. This will allow us to dial in the suspension for whatever we may do with the car today and into the future.
With the new suspension and a 502 big-block under the hood, this car is going to move, and we would like it to stop just as well (if not better). To accomplish this we elected to use Wilwood's Superlite 6 big brake kit. This will net us six-piston calipers and 13-inch rotors up front, which will really put the stops to the car.
If we were to combine the spec of the front and rear stuff we already have, then this car will have a total of 20 pistons and 46 inches of rotor diameter in the brake system. This '56 will definitely stop leaps and bounds better than the four-wheel drums it came with originally.
The following photos will cover how to install all these new goods. In stories to come we will measure for bigger wheels and tires, and then it's time to test all this new stuff, so stay tuned.
1 Here are the main suspension components we received from Heidts. We totally spaced and didn't shoot the sway bar, but it will show up later on in the story. Anyway, the arms are built out of DOM tubing and welded up in a jig. They're 5/8-inch narrower than stock and have added caster built in. This will help with tire fitment and handling capabilities. The cross shafts and ball joints are quality Moog components. The 2-inch drop spindles are forged pieces that is machined here in the US and are made to accept our stock steering arms. The spindles and control arms come ready to use but in raw steel finish so what you see here is after we had everything powdercoated. To hold up the weight and control the bounce, we are using a single adjustable coilover and a set of 650lbs springs. At the time of install, Heidts was just finishing up with their own set of double adjustables, so by the time we go to test this car the doubles will be in place. The springs have a conical shape so the bottom is sized for the coilover, while the top expands out to fit in the factory spring pocket. This way we can run a coilover- bodied shock without cutting a huge hole in our frame for it to pass through.
Stopping performance will come via Wilwood's Superlite 6 big front brake kit with a hub built specifically for the 2-inch Heidts spindle. Along with that we also picked up a 1-inch bore master and the company's new combination proportioning valve and bracket kit. The bracket kit not only comes with bracket to hold the prop valve, but a perfectly bent set of lines to plumb it into the master, making the job at home much easier. The prop valve also has a brake light switch in the end for simplified brake light wiring if your car doesn't have an under dash switch. Since this component has a prop valve built in, it makes adjusting rear brake bias a snap.
3 Here is what we are taking off: stock upper and lower arms with a cut set of coils and a cast set of drop spindles. A 10-inch disc brake swap was done on the car some time ago and worked okay for cruising, but for what we are going to do in the future these brakes would have most likely failed miserably. We don't have enough space here to show you how the front came apart, but suffice it to say we tore it all off to expose the frame for the first step in the installation.
4 Since the arms are narrowed it's going to create interference with the factory bump stop bracket on the frame, so it needs to be cut off. We found a few rivets and two short welds holding our bracket on, nothing a cut off wheel couldn't handle.
5 After we had it off and the area cleaned, we touched it up with some paint.
6 Heidts provides new hardware, which was slipped in place before Lucky Costa, our mechanic for the day, mounted the arm. These arms are nice—all the welds look clean, and there is even a tab for the sway bar end links ready to go. Since Heidts uses OE replacement cross shafts, they slipped right on.
7 The uppers follow right behind and are installed with the shim packs used on our old arms. Again, quality cross shafts and attention to detail in the manufacturing process made sure these fit perfectly.
8 Heidts provides a new bump stop and bracket that they recommend placing here in front of the ball joint, but we found that it would hit at full droop, so we are going to get everything installed and aligned before we place these.
9 If you have never worked with coilovers before, trust us when we say purchase these thrust bearing assemblies. They make adjusting the coils much easier and lessen the chance of galling your components.
10 The springs were slipped over the shocks and then slid up into the factory coil bucket. The top of the coilover is configured the same as the stock shock, so the pin is isolated by two rubber bushings. The bottom of the coilovers has a T-bar mount that mates up to the Heidts arm.
11 Since the top of the coil is basically stock, it must be clocked into the proper position with the end of the pigtail in its respective notch.
12 We had to assemble a few things on the bench before we could continue. The Wilwood bracket kit comes disassembled, so we needed to mount the hats to the rotors with the provided hardware. We used red thread locking compound on all the bolts before we torqued them per the instructions to 155 in-lbs. These bolts can also be safety wired for that added ounce of prevention, but we just didn't have time to do it during the shoot. We will probably pull these back off and do that at a later date.
13 The billet hubs also need some attention. The 1/2-inch studs were threaded into the 5-on-4-3/4 bolt pattern and tightened to 77 ft-lbs. There is also a 5-on-4-1/2 pattern for those other guys. We packed the wheel bearings and then tapped in the rear oil seal.
14 On the spindle we mounted up our factory steering arms. One thing to note is these Heidts spindles are unidirectional, meaning there is no left or right. This might not sound like much, but this little detail will become very important later in our install.
15 Per the instructions, we placed one 0.016 shim per bolt between the mounting bracket and the spindle before bolting it up opposite the steering arm. These shims, which are provided with the kit, are used to center the caliper over the rotor.
16 Now the lift was lowered so we could load the lower arm with a jack to install the spindle nuts.
17 Then we installed the new rotor assembly as if it were stock. One thing to note is the cotter pin. There is not enough clearance between the end of the spindle spud and the dust cap, so the cotter pin must be trimmed as shown and kept from going over the top or it will keep the dust cap from threading on all the way.
18 Before installing the caliper for the first time, two 0.035-inch thick shims per mounting stud were used to space the caliper far enough away as to not rub on the edge of the rotor. These shims will also be used to properly position the pads on the rotor.
19 Now the caliper is temporarily installed to see if the 0.016 shims centered the caliper. In our application they were not; we needed the caliper to move out the thickness of the shim. So we removed the mounting bracket, dropped the shim and put it back on. This got us centered. The shims are provided to compensate for machining tolerances on the spindles, but ours were perfect, so kudos to Heidts for excellent machining. Also, once we slipped in a set of pads we noticed the caliper was just a tad too high, so we removed one each of the 0.035 shims under the caliper and that got us full pad contact.
20 Once happy with caliper alignment, we installed the 90-degree fitting provided in our brake line kit (PN 220-8307). A super small amount of thread sealer was used to prevent any fluid from weeping from around the threads.
21 The new flex line from Wilwood is 18-inches long and has the proper ends to attach to our existing front brake lines. They even fit into our stock frame bracket.
22 Next on the to do list was shorten the tie rod assemblies. Since our arms are narrowed, the steering arms have been moved in. We assembled the passenger's side and then made sure the rotors were sitting straight and the center link was also centered. That allowed us to measure the distance between the two points, which for us was 13 inches. We decided to make our assemblies 12 inches, which will give us a bit of wiggle room to get the steering wheel straight during the alignment.
23 We picked up a new set of sleeves from our local parts store and chopped off 3/4-inch from each side with a chop saw. Then we de-burred the cuts, threaded in the tie rod ends and put them on the car.
24 With the steering out of the way, we moved to the sway bar install. This is when we found a huge clearance issue between the calipers and the end of the sway bar. At first we thought we would not be able to run the sway bar, but before giving up we called the Wilwood and Heidts tech lines. We asked both manufacturers “Are there any issues with moving the calipers to the rear?” Both company tech line guys said, “No problem. That spindle will go either way—just make sure you have no interference with the steering arm.”
We flopped the caliper mounting bracket to the back of the spindle and hoped it wouldn't hit anything. Luckily for us, there is plenty of clearance this way, and now we could turn lock-to-lock with no issues. Whew, crisis averted, plus we think it looks better this way.
26 Knowing our clearance issue was cured, we continued on with mounting the sway bar. The bar installation necessitated us drilling a couple holes on the frame horns for the front mounts.
27 The bar comes with a U-shaped bolt that drops in from the top, through the holes to provide the threads for the Nylok nuts.
28 With all the major components in place we turned our attention back to the brake system. We chucked the new master into the vise and installed the provided bleeding hoses, filled it up with Wilwood's hi-Temp 570 DOT 3 brake fluid and began bench bleeding the master. We kept pushing the plunger in until there were no more bubbles in the hoses.
29 Once we were confident there was no air in the master, we bolted it on to our existing booster. One thing we did that is not shown is re plumbing the rear brake line with 5/16 line. Ours was still the 1/4-inch line for drum brakes, and using it would cause a pressure drop in the rear system due to the larger line. When converting to four-wheel discs, it's best to have the same size brake line going to all components.
30 We started bleeding the system, starting with the caliper furthest from the master (passenger side rear). We used a vacuum- type bleeder to start the process, and once we had fluid coming out of each bleeder we switched to the two person, pump and hold scenario. According to Wilwood, the system wants to see 900 to 1200 psi at the calipers. To check this, we used a gauge threaded into one of the bleeder screws. As you can see, after all the air was out of the system we had proper pressures.
31 The last step was to take out the pressure gauge and install the thin steel wheel shield that will protect the aluminum hat from our stamped steel wheels. If you are running aluminum rims you won't need this, but for stamped steelies you will. This basically keeps the rims from denting the aluminum hub and possibly creating an uneven mounting surface down the road.
32 With that we idled the car out of the shop, checking the brakes as we did. While the brakes stopped the car our pedal felt a bit soft—not spongy, just too easy to push. We made another call to Wilwood's tech line and they told us to check the pedal ratio and distance between the push rod coming out of the booster and the master. We will cover all of this along with proper pad bedding in an upcoming story. Since the car actually stopped fine, we felt confident enough to take her for a cruise. What a difference a day makes. The car feels tight and responsive, even with a 58-year-old steering system. We still have things to do before we can really drive the car, like get it aligned, address the soft pedal feel, and measure for bigger and better rolling stock. Then we are taking her to the track to adjust all our new goodies and see what she can really do.