Brad Walker
July 19, 2007
With more than 500 hp under his right foot, David Sheppard can spin the back tires down to the rims without even knowing it. The four-cam modular mill uses a blower on nitrous with a-gulp-stock bottom end to make the goods. If you want to know David's secret to keeping a stocker together, read on.

Horse Sense: Eventually, even the best-tuned stock modular engines will pop a piston or powder-keg a rod. Luckily, several companies offer bottom-end rebuild kits or complete short-blocks for the modular enthusiasts.

Modular Mustang fanatics face an interesting dilemma when it comes to souping up their pride and joy. The good news is, the top-end components-especially those big-valve-packed aluminum cylinder heads-make for an almost limitless amount of usable street power. The bad news is, in most cases those components are saddled to a set of pistons and rods that can snap like a pencil. Logic tells us to build up the car to the point where we know-or speculate-the bottom end won't take anymore. Then, right before piston skirts lift off, take the thing apart, install the correct parts, and continue the party.

Of course, it rarely happens that way, as more and more modular bottom ends go to an early grave while greedy owners grimace with surprise. Still, we run across those rare modular Mustangs that balance exhilarating power with a stock bottom end, and we're duty-bound to bring you the details.

Meet David Sheppard and his amazingly quick (10.63 e.t. at 124.6 mph) '01 Mustang Cobra. David is no stranger to modular Ford power. In fact, this is his fourth modular Mustang. The first was a '96 GT that sported a 13-psi Vortech S-Trim, a Sean Hyland-built modular short-block, and some of the first Ford Racing Performance Parts heads ever produced for the modular Two-Valve motor. That car ran 10.85 at 128 before someone else had to have it. The following '99 Cobra was a naturally aspirated cruiser that was good for bottom-12s. The second '99 Cobra was a fast street car loaded with a Paxton Novi 2000 and enough beans to run mid 11s on street tires.

Coach at C&T Race Cars did up a nice six-point 'cage and matching subframe connectors to keep David safe and the Cobra's structure intact. The tan leather interior adds the class, while the complete collection of Auto Meter Phantom gauges keeps the driver informed. A Steeda shifter is connected to a Tremec 3650 five-speed trans that transmits power through the 3,340-pound car.

One day, David spotted this True Blue '01 Cobra sitting, of all places, on a BMW dealership's used-car lot. After some wheeling and dealing, David had his next project Cobra. With a solid recipe already in place from his other modular cars, he got to work tuning it up. The centerpiece of the upgrades is a nasty Vortech T-Trim that rips 12.5 psi of boost through the hungry overhead-cam Ford. David also installed an adjustable NOS kit for something extra when the situation called for it. He rounded out a nice collection of supporting hardware you can read about in 5.0 Tech Specs.

David summed up his secret to success with the stock bottom-end combinations that make more than 500 rwhp. "One day there will be a built bottom end in this car. But for now, I'm focused on turning it conservatively. The key to this whole deal is to convert the fuel system to a return-style system, as opposed to the stock Ford returnless style. This allows for a flat fuel pressure to the injectors-no spikes, no surprises. A constant, flat fuel pressure is what it takes for this car to live. I had pushed the '96 to the point of hurting the stock bottom end, and that's what it took to learn this combination."

The best part about this Cobra isn't that it's built within an inch of its life, but rather that David isn't afraid to drive it anywhere and race the tires off it in the process. Racking up street miles in a mid-10-second street Cobra would be cool enough for some folks, but David likes to drag race-a lot. He's no stranger to Freddy Cruz's Clash of the Titans series run in Texas (www.theclashofthetitans.com). There you'll find David blasting off low-11-second times in the True Street cruise at full operating temperature without the aid of the nitrous-another 50 horses and a lot of intake cooling. On top of that, it's a stick.

David crunches gears and busts butts while having the time of his life in the confines of full Cobra creature comforts. He added the rollcage to meet NHRA safety standards, while the IRS had to go bye-bye so David wouldn't have to worry about spitting a halfshaft at 120 mph. With those simple upgrades and a sensible tuning plan, he has one nasty four-cam Cobra that will run with anything it meets on the streets.

If you want a closer look at David's car, check out a Clash of the Titans race, or you might see him piloting his '93 coupe in FFW Renegade or NMRA Drag Radial. That car carries a 414-inch Bennett Racing motor with NOS into action, and it's already seen 5.40 seconds in the eighth-mile as David got used to that car.

As for the future of the Cobra, David says, "I already have the turbo kit [laughs]-it's a 76mm! I'll do the bottom end at the same time I put on the turbocharger. I'd like a nine-second car I can drive anywhere."

With his track record, we know David Sheppard will do just that.

David Sheppard has been around the block-and we don't mean street corners-when it comes to modular Mustangs. Somehow he's been able to crank out 508 rwhp and 456 lb-ft of torque from his stock Four-Valve 4.6 mill. He credits a return-style fuel system, bigger 50-lb/hr injectors, and a conservative tune to the survival of his OEM rotating assembly. The big power comes from an 80mm Pro-M mass air, 13 psi of boost from a Vortech T-Trim, and a 50 shot of NOS when the situation calls for it. Supporting parts come from BBK headers, a MagnaFlow exhaust, Bosch fuel pumps, and an Autologic tune from Steve Drier at Houston Performance [(281) 893-6080; www.houston performance.com]. With the nitrous flowing at 7,500 rpm, this thing can make some noise!



The '01 Cobra is colored in factory True Blue with no external mods. That's nice and sneaky, especially when David is rolling on the stock rims with BFG Drag Radials on the street. An 8.8-inch straight-axle packing 4.10 gears supplanted the IRS, and the front suspension has been beefed up with a D&D K-member/A-arm setup and Tokico adjustable shocks. On the slicks, the Cobra has busted off a 10.63-second e.t. at 124.6 mph with a stout 1.48-second 60-foot dash.




5.0 Tech specs
ENGINE AND DRIVETRAINIgnition
BlockStock, NGK TR-6 plugs
StockGauges
DisplacementAuto Meter {{{Phantom}}} tachometer
281ciand gauges
Rotating Assembly
StockSUSPENSION AND CHASSIS
Cylinder headsFront Suspension
StockK-member
CamshaftD&D steel
StockA-arms
Intake manifoldD&D steel
StockSprings
Throttle BodyD&D coilover
StockStruts
Power adderTokico Illumina five-way adjustable
50-150-horse NOS nitrous system, Wheels
Vortech T-Trim supercharger (12.5 psi)Weld Pro Star
ExhaustTires
BBK 1 5/8-in long-tube headers, Mickey Thompson
BBK off-road H-pipe, MagnaFlow Brakes
after-cat{{{Ford GT}}}
Fuel SystemRear Suspension
Twin Bosch external 255-lph pumps,Springs
Steeda rails, 50-lb/hr injectors,Stock {{{GT}}}
Aeromotive regulatorShocks
TransmissionStock GT
Tremec 3650 five-speed, SPECControl arms
Stage III clutch and pressure plateHPM lowers, Steeda double-
Rearendadjustable upperstraction devices
8.8-in solid axle, TA cover, airbag
31-spline Traction-Lok differential, Wheels
4.10 gears, Moser 31-spline axleWeld Pro Star
 Tires
ELECTRONICS{{{M}}}/T 26x10 ET Drag
Engine ManagementBrakes
Stock computer w/AutologicStock GT
custom tune by Steve DrierChassis stiffening
of Houston PerformanceC&T Race Cars subframe
 connectors and six-point 'cage