Since unsprung weight is also a key factor in handling, I weighed the factory wheel and tire (I had 245/15s on the factory Rallys) and one of the new ones. Despite being much larger, the new wheel/tire only added about a half-pound to each corner. Not desirable, but an acceptable tradeoff, especially considering that we dropped about 5 pounds of unsprung weight per wheel when we swapped the factory cast-iron brake calipers for aluminum Wilwoods a few issues back.
We added the extra inch of width into the backspacing of the wheel, increasing it from 4 to 5 inches. While no modifications were required to fit the wheel to the front of the car, we did find that when turned all the way in, the tires would rub on the front sway bar and frame. We also had to use stick-on wheel weights located well inside the wheel, instead of clamp-ons at the lip where the wheel meets the tire. There was just barely enough clearance to prevent the steering-rod ends from hitting the wheel itself, but they would have taken clamp-ons right off.
With the wheels in place, before I could tear down the front suspension to start stiffening things up, I had to take some measurements. Adding that much rubber in the front of the car increases the amount of strain on the rest of the suspension components. This includes the shock towers, where the upper suspension pivot is mounted. Under hard cornering, these can flex and, ultimately, break. To ameliorate this problem, we ordered a front "spreader bar" from Van Steel. These consist of a pair of brackets that slip over the bolts holding the upper control arms in place on either side, and are then held in place by the factory nuts. The kit also comes with an adjustable round bar with a Heim joint on either end. Each of the Heim joints is bolted to one of the two brackets, tying them together. Since one of the joints is reverse-threaded into the bar, the bar either gets longer or shorter when it's turned.
There are two bars available: one for cars with electric fans, which needs only to be bolted in place and adjusted, and one for mechanical fans. Since there are so many different pulley and bracket variations, the mechanical-fan version comes with the brackets in three pieces, and will need to be welded together. Predictably, mine has a mechanical fan, so I followed the instructions that came with the kit and slipped the brackets into place on the A-arm bolts, mocking up the L-shaped bracket parts until I found an arrangement that would clear the front fan. With everything measured and scribed in place, I dropped the bar off at North Georgia Machine to be welded and got ready to tear down the front end.
The accompanying photos cover the job in detail. The entire breakdown, including time to get the car up on jack stands, took me about three hours, but it bears mention that I had the advantage of having done it before. If you haven't, I suggest using the Van Steel instructional video. It greatly simplifies the process compared to, say, the Haynes manual, which still leaves me mystified about what to actually do. (It does, however, contain the critical torque values for reassembly.)
Unfortunately, you're only half done. You've still got the rear to go…
Check out the rest of the series in Part 2 and Part 3 of the Sure-Footed Shark!