The best time on the slalom...
The best time on the slalom course during the initial testing was 7.29 seconds. After the shock and sway bar changes were made, the car achieved a best time of 6.74 seconds; more than a half of a second quicker! The latest time is comparable to a new Camaro.
OK, let’s be real here. A ’62 Chevrolet Impala is not exactly a prime candidate for a great-handling car. After all, these things rolled off the production line weighing in at 3,455 pounds, are right at 17-1/2 feet long, and stand almost 16 inches taller than a GT-40. And they are suspended on all four corners with nice soft coil springs attached to an X-frame that is, well, less than rigid. It’s not exactly a combination that begs to go road racing, but then some people’s definition of hot rodding is making a car do things it was never intended to do.
Of course we’re not building a car to go racing, rather we’re looking to improve the street handling and performance enough to participate in the autocross events that have become so popular at Goodguys Rod and Custom shows. These timed events are a barrel of fun and will test both the car and the driver. To that end we contacted some industry experts and installed suspension upgrades that made a marked improvement in the handling of this ’62 full-size Chevrolet. The components are not exotic by any means, both front and rear sway bars are of the non-adjustable variety and since the car rides on stock coil springs there is no means to corner balance or even establish accurate ride height on all four corners. It’s a street car that needs help handling, and that is exactly what it received.
Here’s the complete front...
Here’s the complete front sway bar from Chris Alston’s Chassisworks. Assembly and installation of the complete G-street kit is only a one-day job in the garage.
When it came time to improve our Impala’s manners we opted for a matched component suspension upgrade from Chris Alston’s Chassisworks. His G-street kit supplies shocks and antiroll bars matched to our Impala. The installation is straight forward and something almost any shade tree mechanic should be able to handle.
Our first upgrade involved installing a set of VariShock double-adjustable shock absorbers. These high-quality shock absorbers allow us to adjust the rebound (extension) and compression (bump) of the shocks. These adjustments will go a long way to stabilizing the suspension. Curing excessive dive under braking is done with a combination of stiffer front compression and stiffer rear rebound. Tuning shocks will go a long way to improve braking and handling since the weight is now distributed more evenly on all four tires. Installation was nearly a bolt-on affair with the aluminum body shocks replacing the somewhat tired “NAPA’s Best” shock. The only real modification to the car was a small notch in the lower control arm to make room for the adjuster knobs. Once again urethane bushings are used to minimize unwanted movement in the shock mounts. Remember, when installing stud-style shocks the upper nut should contact the bushing snugly, but not compress the bushing. With the front VariShocks installed we moved to the rear where the shocks were a true bolt-on affair. The difference was remarkable and the great thing about the VariShock is the double adjustment is easy to access. Two adjuster knobs on the bottom of the shock provide adjustment for both the compression and rebound. It couldn’t be easier, with one knob for bump the other for rebound you simply slide under the car, give the knobs a couple clicks, and your adjustments are complete.
Here is a comparison of the...
Here is a comparison of the stock bar verses the Chris Alston G-street bar. Our new 1-inch bar dwarfs the old stocker. It should be noted that not all ’62 full-size Chevrolets had a factory sway bar.
Next up was the installation of some fairly stout antiroll bars to limit the amazing amount of body roll the car demonstrated in stock form. The front sway bar is installed in a conventional antiroll bar arrangement. After removing the factory antiroll bar (often referred to as sway bars), links, and brackets we were ready to install the new Chris Alston sway bar. The bar mounts to the chassis and then each end connects to the lower control arm via two drop links. The links are non-adjustable so there is no way to vary the amount of “bar” stiffness, but the beefy 7/8-inch diameter and urethane bushings are designed just for our application. The Chris Alston bar proved to be very effective in cutting down on dreaded body roll.
One good look at the ends...
One good look at the ends of these bars illustrates just how much more roll control power is built into the Alston bar. The hammer finish is durable and attractive.
The rear sway bar is a bit more unique to the X-frame Chevrolet. Rather than the traditional chassis mount and links, the bar is bolted directly to each trailing arm. The preferred method is to mark the location of the sway bar attaching bolts and then remove the trailing arms and drill the two holes in a drill press. However the holes can also be drilled in place, but we recommend you use a drill with a level sight built in to be certain the holes are square to the trailing arm. Once again there is no adjustment on the rear bar, but the two bars were engineered to work well together. Two bolts and spacer tubes per side complete the installation, and in the process complete our suspension upgrades on the ’62.
After the modifications were completed, the old ’62 was run through the autocross and long slalom. Eliminating all body roll from an X-frame Chevrolet may not be within the realm of mortal men, but the VariShocks and Chris Alston sway bars worked in concert to keep the Impala noticeably flatter and our times through the course reflected just that. No doubt the car would benefit from a set of stiffer springs too. But here’s the lesson, you don’t have to go to exotic adjustable sway bars or even coilover shocks to improve handling, you can make a big difference with well-chosen bolt-on items.
The big billet block with...
The big billet block with grease fitting and the new urethane bushing are much more substantial than the old clamp and rubber bushing.
By changing just the shocks and adding sway bars the handling characteristics of the big sedan was greatly improved. As we mentioned, this helped with the autocross times, but improved vehicle dynamics will also make this car safer to drive on the street, not to mention more fun. Let’s take a step-by-step look at just how easy it is to take your full-size early ’60s GM car from a rock and roll cruiser to a more modern handling automobile.
With the bolts removed the...
With the bolts removed the old NAPA shock absorber simply slides out of the bottom of the lower control arm.
Next we removed the two nuts...
Next we removed the two nuts holding the sway bar bushing to the frame. You may have to wedge a screwdriver inside the framerail to stop the nut from spinning.
The new sway bar is slipped...
The new sway bar is slipped into place, basically the old “installation is the reverse of removal” holds true for this kit.
Special assembly lube is supplied...
Special assembly lube is supplied with the kit to help the urethane bushing slide over the new sway bar, a thin coating is all that is needed. Grease stops annoying squeaks and snaps caused by dry urethane bushings.
The bushing is opened and...
The bushing is opened and snapped around the sway bar. Keeping the grease inside the bushings and off your hands will make this operation easier.
Push the supplied Allen cap...
Push the supplied Allen cap bolts up through the billet block and into the framerail. The bolts are long enough to make catching the nut on top easy.
After tightening the billet...
After tightening the billet block bolts, we installed the grease fitting in the block. The bushing has a hole drilled that aligns with the grease fitting to ensure it gets inside the bushing.
The links are tightened enough...
The links are tightened enough to ensure complete contact between the bushing and the sway bar end.
Before we can bolt in the...
Before we can bolt in the new VariShocks we must make a little room on the lower control arm so the adjuster knobs will slide up above the arm. First we marked the area with a pencil.
Regardless of the bushing...
Regardless of the bushing material you should never tighten a bushing to the point of crushing or distorting the bushing. This is an example of an over-tightened bushing.
If your ’58-64 Chevy does...
If your ’58-64 Chevy does not have the factory sway bar brackets on the lower control arm you will have to buy or fabricate a bracket like this that bolts or welds to the control arm.
A small, air-powered reciprocating...
A small, air-powered reciprocating saw was used to cut the notch.
One look at this side-by-side...
One look at this side-by-side comparison made a believer out of us. The VariShock is an aluminum body, double-adjustable shock that will greatly enhance the handling of our Chevy.
After filing the rough edges...
After filing the rough edges of the new notches, we slipped the VariShock up inside the coil spring, pushing the top stud through the upper hole in the process.
The top shock stud was tightened...
The top shock stud was tightened down until the bushing was in firm, full contact with the upper mount.
The lower bolts were tightened...
The lower bolts were tightened and the shock installation was complete. After doing the other side, the front suspension modifications were complete.
The larger body of the VariShock...
The larger body of the VariShock looks very cool inside our coil spring suspension.
A quick test-fit proved the...
A quick test-fit proved the bar would fit perfectly between the two lower trailing arms on the stock suspension. Unlike many sway bars, this bar does not attach the chassis at all.
And here is the completed...
And here is the completed front suspension with the G-street suspension upgrade kit installed on our ’62 Chevy. The components look right at home on the chassis.
We measured back 12 inches...
We measured back 12 inches from the center of the front control arm bolt and made a mark. This would be the location for the front of the sway bar arm. Mark both trailing arms exactly the same.
With both trailing arms marked...
With both trailing arms marked we carefully clamped the sway bar to both bars and marked the hole locations. Note the small piece of rag under the clamp to protect the hammer finish.
We were only half done with...
We were only half done with the project, now it’s time to mount the rear antiroll bar. This would prove to be a simple modification.
We carefully outlined the...
We carefully outlined the oval holes in the sway bars onto the trailing arms. Make certain the sway bar is centered on the trailing arm top to bottom.
After marking the trailing...
After marking the trailing arms the best method is to remove the trailing arms for drilling.
After the holes have been...
After the holes have been drilled in the trailing arms insert the supplied sleeves into the bottom of the control arms. Due to variation in control arms you may have to file or face grind these sleeves to fit.
Strike a punch in the center...
Strike a punch in the center of each oval opening, this will provide fore and aft adjustment on the bar should it be needed after installation.
With the spacer sleeves in...
With the spacer sleeves in place, simply bolt the sway bar to both lower control arms with the high-quality hardware supplied in the G-Street kit.
After carefully setting the...
After carefully setting the trailing arm up in a drill press we drilled two perfectly vertical holes through both sides of the trailing arms.
The rear VariShocks are truly...
The rear VariShocks are truly simple bolt-in replacements. Note how easy it is to adjust rebound and extension on the double-adjustable shocks. Simply crawl under and add a few clicks to the adjuster knobs.
It is possible to drill the...
It is possible to drill the trailing arms in place as seen here, but take special care to drill the holes at a true 90-degree angle to the face of the trailing arm.
And here’s the finished rear...
And here’s the finished rear suspension with the Chris Alston upgrade. Again, this is not a full-on race car suspension, rather it is a dramatic street and autocross suspension upgrade that makes a huge difference in the car’s handling.