Get a Grip

Stuffing The Largest Tires Under All Four Camaro Generations

Scott Crouse Jan 1, 2002 0 Comment(s)

Step By Step

It is crucial to check for clearance with the suspension at its normal ride height. With the car on jackstands, position a floor jack under the lower control arm to achieve the desired ride height.

Notice how we lengthened the wheel studs in order to gain clearance around the spindle. Be sure to account for this offset when taking your backspacing measurements.

A common suspension piece that comes into contact with a deep offset wheel is the tie-rod end. One trick to get around this is to use a larger-diameter wheel that will tuck the tie rod inside, allowing additional backspacing.

The upper control arm on a first- generation Camaro will hit a wheel with too much backspacing, so be aware of this pitfall.

Be sure to measure all points from the spindle centerline located between two parallel wheel studs.

Swapping to a tubular control arm may be all that’s needed to gain additional upper control arm clearance.

7 Proper backspacing is the key to getting your tire and wheel combination to fit. Simply measure from the center of the wheel to the outer edge of the tire and wheel.

The most common area of outward interference is the fender lip. Here we take suspension travel into consideration.

One of the worst feelings you can experience in an automobile is losing traction and drifting out of control. The sensation of weightlessness overcomes your stomach, and you are helpless until the tires grip the pavement again. When it’s all over, you’re left sitting there with your heart pounding.

We’re sure many Camaro enthusiasts have shared this feeling over the years. There are many factors involved in keeping a car glued to the ground, but it all comes down to the tires. Stuffing the largest tires and wheels under a car will not only improve traction, but drastically alter the appearance as well. Since we’ve all lost control at least once, we looked into fitting fat tires and wheels under all four Camaro generations.

The first step in a project like this is to determine the ride height of your vehicle. This will affect the many factors relating to tire and wheel clearance. Once the ride height is set, we can begin our search for the most rubber. Using the tallest, widest, and deepest offset wheels will allow your Camaro the maximum amount of traction and style. Purchasing several tire and wheel combinations until you stumble upon the correct size would be expensive and frustrating, so we designed an easy-to-use, dirt-cheap tool to determine the largest tire and wheel we can use.

Tooling Up

Our homemade tool requires one piece of 1½x1-1/8-inch angle iron approximately 18 inches long, a 10-inch piece of ¼-inch all-thread, two ¼-inch nuts, six lug nuts, and two long wheel studs. We recommend purchasing angle iron and all-thread in excess lengths to fit your application.

Under Construction

We constructed this tool by first drilling a 7/16-inch hole about 1-inch in from one end of the angle iron. Since we are using this tool on the standard midsize Chevy 5x4-¾-inch wheel bolt pattern, we drilled the second 7/16-inch hole 4-¾ inches farther into the angle iron. Exactly halfway between these two holes is the spindle centerline. Measured from the spindle centerline, we drilled a series of ¼-inch holes that represent the wheel diameter. Since we’re working with the radius, a 16-inch wheel diameter would be an 8-inch distance from the spindle centerline. To this distance, we added ½ inch to account for the thickness of the wheel lip. For 15-, 16-, and 17-inch wheels, we drilled three ¼-inch holes at 8, 8-½, and 9 inches from the spindle centerline. Next, we drilled a series of ¼-inch holes farther down the length of the angle-iron to represent the sidewall width of the tire. For these dimensions, we chose radius lengths of 12, 12-½, and 13 inches to account for 25-, 26-, and 27-inch tall tires, because the widest portion of the tire occurs roughly an inch or so shy of the maximum radius of the tire.

Finally, we used a piece of ¼-inch all-thread as a pointer to indicate if the tire and/or wheel would clear the wheelwell. This length of all-thread can be used to check both the inboard and outboard dimensions for both the wheels and tires. For wheels, inboard clearance is the most important checking point due to possible interference with suspension parts such as tie rod ends, shock mounts, and upper control arms. But inboard and outboard sidewall clearances are critical for the tire too.

Hook It Up

We pushed two wheel studs through the angle iron and threaded lug nuts onto them to hold the angle-iron in place. Then, using two more lug nuts to join the car studs to the studs in the angle-iron, we relocated the clearance tool. The relocation of the tool causes the measurement to become distorted since the tool is several inches from the mounting surface of the hub. Be sure to account for this additional offset. The rear axle hub will also have some offset to be accounted for.

Crunching Numbers

When measuring front-end clearance, we had to take three separate readings to account for steer and wheel travel. The rear is much easier because the axle is limited to mostly vertical travel. Once the clearance tool has been bolted to the front rotor and rotated 360 degrees, the closest points of contact can be measured. A typical area of inward interference is the tie-rod end so let’s look at this measurement. The first data to record is the distance from the tip of the all-thread pointer to the angle iron. Then measure the distance of the angle iron to the hub itself. Subtract these two measurements from one another to find your maximum inward offset. Perform the same procedure with the all-thread pointing outward to determine fenderwell clearance. Playing with different offsets will allow you to optimize the wheel backspacing for the widest tire and wheel combination. The best method combines maximum backspacing with the widest wheel possible.

The Final Frontier

Measuring backspacing is quite simple. It requires a straight edge to be placed across the wheel from lip to lip or across the tire from sidewall to sidewall. With the straightedge in place, measure inward to the mounting flange on the wheel. If the clearance-tool measurement is greater than the spacing of the wheel and tire, chances are things will fit. Any measurement within ½ inch or less should be checked with an actual tire and wheel. When things get this close, it is best to use a borrowed tire and wheel before purchasing those pricey aluminum pieces.

Throughout the history of the Camaro, there were subtle modifications that may affect aftermarket tire and wheel clearances. For example, ’67 Camaros had both shocks mounted ahead of the rear axle, while the ’68 and ’69 Camaros changed to a staggered rear-shock design. The ’69 Camaro’s front and rear wheelwells were also changed slightly. Every Camaro from every generation is unique in its own way, and depending on the ride height and chassis modifications, every application will vary slightly. This quick overview of fitting large tires and wheels should get you started in the right direction without rubbing you the wrong way.

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