Project Fox 1993 Ford Mustang - Mission Accomplished!
Our ’93 Mustang project car finally goes 9.81 at 141 mph—for a total cost of around $25K, including the car
From the May, 2012 issue of Popular Hot Rodding
By Stephen Kim
Photography by Author
After months of searching...
After months of searching for reasonably priced Camaros and Novas to no avail, we stumbled upon a Craigslist ad for a clean ’93 Mustang 5.0L notch. It wasn’t our first choice, but at $3,000 for a car that needed zero rust repair and had loads of potential, we couldn’t pass it up.
Gentlemen, we have ourselves a 9-second car. Despite our best efforts to exercise professionalism and composure during what should be a triumphant moment, all we can say is that it’s about freakin’ time. Way back in the Dec. ’10 issue, we boldly proclaimed that our street/strip ’93 Mustang project car would be running 9s much sooner than anyone expected. Considering that it ripped a 10.54-at-138-mph pass on its maiden trip down the track, there was good reason for our optimism. As the incessant and increasingly frustrating track excursions unfolded, however, we quickly realized that our assessment was a bit premature. With time and money always at a premium, finding those last few hundredths of a second in e.t. proved excruciatingly difficult. While it’s somewhat embarrassing that it took so long to hit the single digits, we’re not making any apologies. That’s because we can now load up the converter to 4,000 rpm, pop the transbrake, and bust off a 9-second pass at will on any given test-and-tune night.
Once you start making some...
Once you start making some power, driveline failure isn’t just a nuisance, it’s a safety issue. We opted to build the stock 8.8 rearend instead of swapping in a 9-inch, due to its lower mass, lower cost, and parasitic power loss. It’s been beefed up with Strange 33-spline axles, C-clip eliminators, spool, girdle, main caps, 3.90:1 gears, and a 1350 yoke. Bill Buck Race Cars added the trick back brace, and for a total investment of $1,759, the rearend has never once let us down.
The 9-Second Plan
In today’s glorious era of performance, where horsepower oozes out of the Summit catalog like subscription cards exploding out of a magazine, building a 9-second car isn’t all that difficult. What makes the feat a heck of a lot more challenging is doing it in a street legal, naturally aspirated, pump-gas-burning, full-interior package all for under $25,000. We figured even that’s not hard enough, so we decided to get the job done on drag radials and a stock-style suspension. Remove any of those prerequisites from the equation—by gutting the interior, dumping in some race gas, bolting in some ladder bars, or throwing on some slicks—and the task at hand becomes much easier. However, as JFK so eloquently put it, we sought to transcend these challenges “…not because they are easy, but because they are hard.” With prophetic lines like that, maybe Jack should have been a drag racer.
To recap, Project Fox started out as a stock ’93 Mustang notchback with a 302 and a five-speed stick. Since these cars are cheap, weigh next to nothing, and easily swallow up a big-block, we were willing to look past its uninspiring late-model lines for its practical benefits. After selling the stock motor and trans to recoup a few bucks, the car got shipped off to Bill Buck Race Cars in Austin, Texas, for a 10-point chrome-moly rollcage. Buck’s uncanny ability to discretely tuck a ’cage tightly into an interior resonated with our street cruising intentions, and the end product didn’t disappoint. While at the shop, the rear suspension was fortified for severe drag duty with a set of Competition Engineering upper and lower control arms, coilovers, and antiroll bar. Up front, we opted for an Anthony Jones Engineering tubular K-member and control arms matched with Strange shocks.
With a 10.320-inch deck height,...
With a 10.320-inch deck height, a 385-series big-block Ford is a tight fit between the shock towers of a Fox Mustang. Surprisingly, spark plug access is pretty good. Removing off-the-shelf headers, on the other hand, is a major pain. Nevertheless, there’s nothing cooler than seeing a huge motor squeezed inside a tiny car.
With the car itself taking shape, it was time to add some horsepower to the equation, so we hooked up with the School of Automotive Machinists (www.SAMRacing.com
). When it comes to streetable, naturally aspirated, pump-gas–friendly horsepower, it’s tough to beat the easy cubic inches afforded by a big-block Ford. As such, SAM started with a stock 460 Ford block, opened up the bores to 4.440 inches, and stroked it to 532 ci with a Scat rotating assembly. The ace up the motor’s cylinder sleeves is a set of Jon Kaase Racing P51 cylinder heads that flow an astonishing 400 cfm right out of the box. Matched with an Edelbrock Victor intake manifold, a Holley 1,150-cfm Dominator carb, and a COMP 273/280-at-.050 mechanical roller camshaft, the combo cranked out 775 hp on SAM’s SuperFlow engine dyno. To eliminate any potential driveline snafus, the big-block was mated to a Phoenix Transmission Products TH400, and a stock 8.8-inch rearend beefed up with Strange internals.
Initially, the plan was to...
Initially, the plan was to build a big-inch small-block Windsor with Cleveland heads and gun for 700 hp. Upon realizing that a motor of this caliber would cost close to $20,000, we decided to build a big-block instead. For a grand total of $9,644, complete from carb to oil pan, the School of Automotive Machinists in Houston built us a 786hp big-block that loves to take a beating.
As of our last report in the Mar. ’11 issue, Project Fox clicked off a series of 10.0-second passes at Lonestar Motorsports Park in Sealy. Launching off the footbrake, the car ran a best of 10.01 at 137.89 mph on a 1.47-second 60-foot time. One freakishly good launch notwithstanding, the 60-foot times had stagnated in the 1.50- to 1.59-second range, so the next logical step was installing a TCI transbrake. Unfortunately, during our next trip to the track, the 275/60-15 Mickey Thompson ET Street radials couldn’t handle the additional shock placed upon them by the transbrake, sending them into violent tire shake. Stiffening up the rear shocks and increasing tire pressure helped the situation, but the best pass of the night was a disappointing 10.21 at 137.49 mph on a 1.67-second 60-foot time.
Shortly thereafter, the local tracks went into a brief reprieve for the winter holiday season. That wasn’t a bad thing, since an improperly shimmed starter had ripped the teeth off of the Mustang’s flexplate, and it gave us time to pull the trans and patch everything back up. Once back on the road, the next couple of test sessions revealed an ugly truth about the drawbacks of running radials instead of slicks. While the radials work great under ideal track conditions, they proved to be extremely finicky and unforgiving in cold weather. Once the ambient air temperature dropped into the 30s, they refused to hook regardless of changes in suspension tuning. Pulling timing coming out of the hole with the programmable MSD 6AL-2 ignition box didn’t help, either.
Not only is the AJE K-member...
Not only is the AJE K-member 34 pounds lighter than the stock unit, it’s compatible with multiple styles of motor mounts that makes dropping in a big-block a bolt-in affair. The stock steering rack went in the trash, and got replaced with a Unisteer manual rack.
Consequently, we sat things out for the rest of the winter. Unfortunately, Mother Nature decided to skip spring altogether and jump straight to summer. This wasn’t just any summer, but the hottest summer in Central Texas history, with 90 days in which the temps topped 100 degrees or more. We reasoned that any potential improvements in 60-foot times would be offset by a big hit in horsepower, so we patiently awaited some cooler fall air. Call us pansies, but the prospect of roasting in a black fire suit in the staging lanes wasn’t very appealing, either.
Once September rolled around, the daytime temps were finally back down into the 80s, so we headed back out to San Antonio Raceway. In an effort to eliminate the tire shake that had plagued our prior runs off of the transbrake, chassis man Bill Buck made changes to the Mustang’s instant center. By relocating the rear of the lower control arms upward, and thereby moving the instant center closer to the front of the car, the goal was to reduce the rate of weight transfer to the rear tires, and keep them loaded up longer after launch. Fortunately, it worked. After popping the transbrake at 3,500 rpm, Project Fox ripped off a 9.95-second pass on a 1.42-second 60-foot time. The car decided to pull left at the far end of the track, which forced us to lift right before the finish line, but it still coasted to a single-digit pass with a 130.55 mph trap speed. Finally, after a year’s worth of testing and tuning, we had ourselves a street legal, naturally aspirated, pump-gas–friendly, full-interior car that runs 9s on a stock-style suspension for under $25,000.
Among the things we like most...
Among the things we like most about Project Fox is its street-friendly interior. It has real seats, a real dash, and real door panels as well as power windows, locks, and mirrors. There’s a stereo, too, but good luck trying to hear it over the big-block.
Having met our goal of running 9s while staying within our budget, we were itching to see how much quicker the car would go with some simple, long overdue mods. The goal this time around wasn’t to pick up tons of performance for the dollar, but rather to improve the consistency of the car. First off, Project Fox needed to shed some weight off the front end with a set of skinnies. The car’s oafish 15x7 front wheels and Mickey Thompson 26x10x15 Sportsmans worked great on the street, but just didn’t look right on a wheels-up drag car, as some very vocal readers pointed out. To address the situation, we ordered a set of 15x3.5 Billet Specialties RT front wheels paired with Mickey Thompson 26x4.5 ET Front tires. Out back, we bolted up a matching set of 15x10 RTs and wrapped them in some well-worn MT 28x10.5x15 ET Drag slicks. Likewise, since factory front brakes were a bit marginal for our application, we replaced them with a set of 11-inch Wilwood Dynalite drag brakes. Between the skinnies and the drag brakes, we knocked a solid 60 pounds off the front of the car.
Project Fox’s TH400, built...
Project Fox’s TH400, built by Phoenix Transmission Products of Weatherford, Texas, never ceases to amaze us. At $1,945—a price that includes a two-year, 24,000-mile warranty—it’s an incredible bargain. It’s rated at 900 hp, so apparently we’re not making enough power to break it. Trust us, we’ve tried.
Underhood, things got spiced up a tad as well. Since Project Fox has always battled inconsistent 60-foot times, we called up COMP Cams to see if the valve events could be tweaked to tailor the torque curve to better suit our application. As the techs at COMP explained, it’s very common for small-tire drag cars to run relatively wide lobe-separation angles to move the torque peak higher up in the rpm range. This eases the hit to the tires coming out of the hole while tacking on a few more ponies up top. Whereas Project Fox’s original cam was ground on a 109-degree lobe separation, COMP spec’d out a new one at 114 degrees. Furthermore, the new stick measured 278/290 degrees of duration at .050 versus the original’s 273/278 degrees at .050, again to soften the low and midrange torque. On SAM’s dyno, the numbers played out just like COMP predicted. From 3,500 to 4,000 rpm, the new cam was down an average of 50 lb-ft of torque, but the horsepower peak was now at 6,700 rpm instead of 6,500. Overall, the new cam produced 11 more peak horsepower than the old one, but more importantly, it blew the old one away at 6,800 rpm, at which point it was making 39 more horsepower.
Think you need ladder bars...
Think you need ladder bars or a drag-style four-link to run 9s? Think again. Project Fox’s Competition Engineering suspension kit—which includes the control arms, coilovers, and antiroll bar—is more than up to the task for less than $1,500. The single-adjustable shocks came in handy on dozens of occasions for easy on-track tuning.
To put it all to the test, and for one last hurrah down the track, we headed back to San Antonio Raceway. Airing the slicks down to 13.5 psi and leaving at 3,500 rpm off the transbrake netted an all-time best of 9.81 at 141 mph on a 1.40-second 60-foot time. On the next pass, we increased the launch rpm to 4,000, which netted a quicker 1.38-second 60-foot, but a slower overall pass of 9.84 at 140 mph. Although the car only picked up slightly more than a tenth—which is by no means insignificant at this power level—the car’s consistency was substantially improved. Unlike with the radials, which required constantly changing the MSD’s launch retard curve depending on track conditions, the slicks allowed leaving off the ’brake with full timing advance every single time. Moreover, the Mustang pulls 60-foot times in a 1.38- to 1.44-second range all night long, and consistent 9.80s pass after pass. Like we said up top, mission accomplished!
Even if this next bit sounds like an infomercial, we don’t care. We’ve been beating on Project Fox like a dissident in a Cold War prison camp, logging 100-plus passes over the last year, but it refuses to break parts. That’s a testament to the premium quality components that went into the build, as nothing tests the performance and durability of aftermarket parts like an inclement track environment.
After trading notes with some...
After trading notes with some small-tire racers at the track, we realized that Project Fox could benefit from some slightly tweaked cam specs. We called up COMP Cams, told them what we wanted, and boy did they deliver. Simply widening up the LSA from 109 to 114 degrees dramatically improved the car’s launch consistency.
So without further delay, thanks to the School of Automotive Machinists for building one bulletproof lump. We’ve zinged the 532 big-block well past 7,000 rpm run after run, and it keeps on ticking. The same goes for Project Fox’s TH400 transmission. Interestingly, Phoenix Transmissions says that they don’t build race automatics, but they could have fooled us. We’ve been pounding on this thing since day one, whether it’s by slamming the gears or popping the transbrake, and it just laughs in the face of abuse. We can’t count how many people at the track have marveled at how hard it shifts. The driveshaft and rearend the Phoenix TH400 is attached to are equally impressive. Project Fox’s Strange-fortified Ford 8.8-inch rearend has never flinched despite the countless burnouts and launches under its belt.
Of course, running our target e.t. would never be possible without some premium suspension hardware. The Competition Engineering rear suspension just flat out got the job done. Likewise, our chassis man Bill Buck says, the Anthony Jones Engineering K-member and front suspension are among the nicest he’s ever seen for a Fox application. And last, but certainly not least, we have to give a huge shout-out to Bill Buck Race Cars. We were so pleased with Buck’s work that what started out as a rollcage job quickly turned into a complete drag car build. Sure, we dropped in when we could to lend a hand, but the crew at BBRC handled the bulk of the Project Fox build, from the chassis fabrication to the rearend build to the wiring. If you’re in the neighborhood and need a good shop, you can’t go wrong with BBRC.
Billet Specialties RT wheels...
Billet Specialties RT wheels not only look sweet, they’re also SFI approved and dirt cheap to boot. The front 15x3.5 wheels are just $210 a pop, while the 15x10 rears will set you back $260 a piece. They boast two-piece construction, and will accommodate ⅝-inch wheel studs.
That puts the wraps on our ’93 Mustang, as we’re now officially retiring it from the PHR project garage. Even so, that doesn’t mean we’re done messing with it, not by a long shot. As it turns out, a 9-second street car lives in a bizarre no-man’s land. A car like this is faster than 90 percent of the street cars that show up on test-and-tune, which sounds like a good thing at first, until you realize that it’s just fast enough to run with some all-out race cars. The bad news is that in the walk of all-out race cars, Project Fox is slower than 90 percent of them, and at the end of the day, the timing lights don’t care what kind of fuel you’re burning, or whether or not your car has power windows and a stereo. We have no intentions of transforming Project Fox into a gutted, race-gas-burning, unstreetable package. Instead, we want to keep the street car vibe, throw on a pair of turbos, and shoot for 7s on pump gas. Wanna watch? Let us know!
After a long reprieve and...
After a long reprieve and an instant center adjustment, Project Fox ripped off its first 9-second pass. At this point, however, we’d made dozens of passes in the car and were numb to the power. Who knew that a 9-second car could feel so slow?
There’s a lot to like about...
There’s a lot to like about the Mickey Thompson 275/60-15 ET Street radials. On a good track, they hook like crazy, and are very stable thanks to their stiff sidewalls. However, they’re far less forgiving than a traditional bias-ply slick in less-than-ideal track conditions. On your typical test-and-tune night, when track prep is minimal at best, it can be quite a chore to try to get them to work. For consistency, you can’t beat a real slick.
When roaming town looking...
When roaming town looking for street vermin, Project Fox looks like any other poser Mustang. It’s a car you can certainly make some money with, if you’re into that kind of thing. One of the only downsides of the big-block is the big ugly hood it requires for carb clearance. In case you were wondering, 786 hp in a 2,950-pound car is ridiculously entertaining on the street.
Magazine guys aren’t the smartest...
Magazine guys aren’t the smartest people out there, so if we can build a 9-second car on the cheap, so can you. In the meantime, do you have a power adder we can borrow?