Little Tire Traction, Part 2

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How to Set Up a Stock Suspension Car

In our initial look at stock suspension car set up, we devoted all of the space to the back end of the car. This time we’ll look at the front. Just like the aft pieces, bolt-in hardware for the nose is readily available for plenty of cars, and it’s equally sophisticated. We used a GM G-Body as the example for the first article, and we’ll do the same here, but keep in mind, what works on the nose of the Buick also works on plenty of other cars, too.

The stock front suspension components bolted to your car were not optimized for quarter-mile use. Typically, the cars like our Buick have considerable camber change as the front end goes through its travel.  You can really see the change as the car dangles the front end in a wheelstand. The takeoff and flight part of a wheelstand is easy, landing isn’t. The result is often a series of hairline cracks on factory A-arms.  That’s a big reason why quality materials are important for front suspension hardware. The same applies to the welds and component finishing. A-arms are no place for lousy material choices or backyard welding.

These are the pieces we’ll be using. With a G-Body, the wheels flop as the nose rises. To fix the camber change, Autofab Race Cars reworked the geometry of the arms, which built in more positive caster. This allows the car to track straight at speed. Autofab recommends trying to get 0 degrees of camber and 2-4 degrees of positive caster when aligning the front end. (Autofab’s A-arms will allow for a maximum of 8 degrees of positive caster.)

To set the wheel alignment on these A-arms, you can use conventional shims, but since they’re equipped with rod ends (instead of solid arms with bushings), you can back off the jam nut and turn the rod end in or out. For the top you have to remove the cross shaft, then adjust the bearing and replace the cross shaft.  The reason this A-arm is not intended for street use is because the cross shaft is aluminum (we had an identical cross shaft machined from billet steel for our car). The lower A-arm adjusts in a similar fashion: Remove the attachment bolt on each side of the lower and pull out the A-arm (keeping in mind there’s a spring enclosed). Then turn the rod end in or out.  In most cases, once the basic alignment has been completed, you’ll seldom have to touch the lower A-arm. This setup provides considerable adjustment capability.  You can work out the camber curve using both the top and bottom, and then fine-tune the top A-arm settings.

Here’s a look at the rod ends for both of the upper A-arms (the bottoms are similar). Not shown, the lower A-arm is fitted with a sleeve and has a spacer on each end so that the arm fits directly into the stock frame A-arm pocket.

The other big dilemma with drag race A-arms is controlling suspension travel. It’s no secret that huge suspension travel can be a good thing on low-powered cars or on greasy tracks, but if the horsepower wick is turned up, and/or there’s some bite in the track surface, then adjustability in the A-arms becomes important. In those cases, having some way to control the travel so that you can limit a wheel stand is extremely important. It becomes critical if you campaign a car in any of the heads-up street car organizations that prohibit wheelie bars.

Both the upper and lower A-arms are constructed from chrom-moly (4130) steel. Each arm is assembled in using several fixtures, and then TIG welded. Keep in mind that many A-arms out there are built from mild steel, not chrom-moly. You may be able to shed as much as 30-35 pounds of unsprung weight with this type of setup.

Most drag race-oriented tubular A-arms can be purchased for conventional springs and shocks or for coil-overs. The coil-over setup provides more tuning capability. If the car sees street use, we recommend a conventional spring arrangement, as shown here.

Another part of the front-end equation that is absolutely essential in a drag race car is the front bushing choice. Some A-arms make use of bushings that just don’t work for drag racing. If you’ve been around the block with drag race suspension, you’ll find the road-style urethane bushings have a tendency to stick (or as Penske and other big time suspension folks refer to it, “stiction”). When the component experiences stiction, the offending material (such as urethane) more or less freezes up the suspension component, rendering the shock useless. That’s why bushings that experience stiction don’t work well for drag race applications. And A-arms that make use of a bearing or use some form of Del-A-Lum bushing are far better suited to drag race applications.

Drag race applications benefit from a suspension travel limiter. Most aftermarket A-arms come with one built in. Rather than using spacers and big traction bar snubbers, the Autofab comes equipped with large ½-inch fine-thread bolts, complete with jam nuts. For a relatively slow car you’ll need more suspension travel, quicker cars need far less. Powerglide-equipped cars tend to want more travel than something like a Turbo 400 or a stick. 

Servicing a part is always a consideration. The Autofab A-arms use an upper ball joint, which is a stock GM bolt-in piece for a G-body. The press-in lower ball joint is also a stock item, meaning service parts are readily available.

One more item to consider: virtually all of the aftermarket road race-style A-arms come equipped with mounting tabs for front sway bars. You don’t need a front sway bar on a drag car. Because of that, A-arms intended for drag racing don’t have provisions for the sway bar bracket.

If you do a bit of homework, you’ll find there are a number of companies building custom A-arm setups for common drag race platforms (GM G-Body, etc.). But what should you look for? Here’s how we set up our project Buick. Copy the plan; it’ll definitely work.

 

Manual Steering Conversions

The steering on your race car is usually a simple arrangement, either a rack-and-pinion or a conventional manual box. For many later model cars, it’s not that simple. Most of those production line cars came equipped with power steering standard. There’s no cheap and light manual alternative. In something like our Regal, adding a rack gets complicated. So what’s the easy answer?

Here’s the 525 steering box used in our project G-Body. The 525 is much stronger than a Vega box, and isn’t much bigger.

The Borgeson GM steering box swap kit includes a new high-strength pitman arm. It’s designed to adapt the 525 box to the steering arrangement used in your car. Installation is the same as a stock OEM part.

Two good choices include the GM Saginaw 140 and the Saginaw 122/525 box. The 140 is the hugely popular Vega manual box.  Produced from 1971-77, this box was used on four-cylinder applications only. The 140 box has a number of favorable characteristics: It’s very compact and light, a bit more than 11 pounds. They can be rebuilt, and companies such as Borgeson offer a blueprinted box with a 22:1 steering ratio.

A ½-rag joint is included in the kit, but it isn’t required for all applications. On some applications, a flexible coupling was used to attach the column to the steering box when there was perfect alignment. If the original column or box is changed, the stock coupling may not work, hence the ½-rag joint here. It can be attached to the other half of the factory rag joint (on the steering shaft side).

Once the steering box is bolted into the frame and torqued to specs, fasten the OEM steering shaft to the steering box input shaft, using the factory hardware. We discarded the plastic sheath covering the collapsible shaft; it’s cleaner this way. The steering box bolt pattern (frame mount) is the same as stock and uses all OEM hardware.

The stock 140 steering box is best suited for cars that weigh less than 2,500 pounds. It’s a natural for cross steer situations and because of the small size, it fits well in tight quarters. While the 140 box is small and light, remember that the Vega was a light car with a very light front-end weight.

The Saginaw 122 box looks similar to the 140, but it’s a little bit larger and definitely stronger. Two ratio steering boxes were available: 16:1 and 24:1 (The pitman arm length has an affect upon the ratio of the steering box. The above ratios assume the box has a 6-inch pitman arm).  The 122 steering box features a mount pattern that is identical to the Vega box, but it is physically larger than the 140. Another option is the Saginaw 525 model. It seems almost identical to the 122, but it has a stronger casting along with a larger cap. The 525 was used in a number of passenger car applications, along with some light-duty pickup trucks (e.g., Chevy’s S-10). Borgeson points out that this is a very stout, reliable steering box. The 525 box is available with a 1-inch or 3 1/2-inch-long input shaft and either a 16:1 or 24:1 steering ratio.

Splines and shaft sizes for the various manual steering boxes are as follows:

Box Type                                    Spline Count                      Shaft Size

Saginaw 140                                    36                                         5/8-inch

Saginaw 122                                    30 or 36                               3/4-inch

Saginaw 525                                    30                                         3/4-inch
Borgeson has a large number of new and blueprinted steering boxes in its catalog. When it comes to rebuilt boxes, the company buys large volumes of cores, chemically strips them, inspects each part, replaces or remachines anything worn, and then carefully blueprints each box to exacting factory specifications.

The company also manufactures power-to-manual steering conversion kits for four different GM families: 1978-88 Malibu (Monte Carlo, 442, Grand National, etc,), 1968-72 Chevelle (442, Skylark, GTO, etc.), 1964-67 Chevelle (442, Skylark, GTO, etc.) and 1970-81 Camaro (along with 1975-79 Nova, Omega, etc.). These particular swap kits include a 525 steering box, a correct pitman arm and ½-rag joint (where needed). Even though this is a robust system, it still works out to a weight savings of 28 pounds in comparison to a factory power system.

 

Text and Photos by Wayne Scraba

 

 

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