In stock trim, notchback Mustangs...
In stock trim, notchback Mustangs weigh roughly 3,000 pounds. Despite the addition of a big-block, TH400 trans and a 10-point 'cage, we were shocked when Project Fox tipped the scales at 2,850 pounds. Once we fit it with a cowl-induction hood, gas it up, and fill it with oil and trans fluid, that number should be closer to 2,950 to 3,000 pounds.
Anyone can do the big-inch, big-cam, big-compression thing and make a ton of horsepower these days. The real measure of automotive manhood is how quickly you can get that power to move you down the track. With 532 ci, a 273/280-at-.050 solid-roller cam, and 11.0:1 compression, Project Fox's SAM-built 775hp big-block Ford certainly puts out more than enough grunt to reach our target of breaking 9s in the quarter-mile. Nonetheless, there's a big difference between potential and on-track performance, and all we have right now is the former. To make things even more interesting and to stay within our self-imposed $25,000 budget, we decided to do the deed with a stock-style suspension and Mickey Thompson drag radials. To that end, our 1993 Ford Mustang has been fitted with an AJE tubular front suspension, a Competition Engineering rear suspension, and coilovers (CE in the rear, Strange up front) at the corners. Even so, installing premium suspension components is just the first step in a multiphase process. To stand any chance of hooking up, much like an engine, a suspension must get dialed-in with a solid baseline tune before final tweaks can be made at the track. That takes experience and expertise, which is why we called Bill Buck Race Cars to help us out with "Step Two" before making some passes.
Before any adjustments are...
Before any adjustments are made, Buck likes to put all four shocks on their softest settings to allow the suspension to settle, and to check for binding throughout the range of motion. While holding a straightedge to the face of the front wheels, an angle gauge revealed that there was 2 degrees of positive camber. This can make a car twitchy, and also wears out the outer edge of the tires more quickly. The large 26x10x15 front tires on Project Fox exacerbate this condition, but skinnies are less prone to uneven tire wear due to their rounded edges.
For anyone who hasn't been keeping up with Outlaw 10.5 drag racing, the prospect of trying to put down this kind of power without the luxury of ladder bars or a full-race four-link probably seems absurd. Truth be told, however, Fox Mustangs are running as quick as high 6s at over 220 mph on stock-style suspension and drag radials. Granted, that's mighty impressive, but the term "stock style" is a bit ambiguous. Although Project Fox retains its factory four-link architecture, and its stock suspension pickup points haven't been moved, the control arms, shock valving, ride height, and rear sway bar are all adjustable. This allows for a fair amount of tuning flexibility, but the downside is that novices can easily get overwhelmed. Having built dozens of 7- and 8-second small-tire drag cars, our man Bill Buck is up to the challenge. "You never know what a car is going to do until you make some passes at the track, but it's still very important to get the baseline suspension tune as close as possible," he says. "That makes the suspension much easier to dial in on race day. We've built enough of these cars to know what works and what doesn't work."
During an afternoon of tuning, Buck set the ride height, camber, caster, shock valving, corner weights, and instant center. Suffice it to say that the science behind suspension tuning isn't exactly common sense, and is often counterintuitive. Furthermore, anyone who claims that a drag-oriented suspension is much easier to set up than a road race suspension has obviously never built a fast straight-line machine. Nonetheless, following the advice of a seasoned pro like Buck goes a long way in getting maximum bite the first time.