Building a 1,627 HP 2007 Ford Shelby - 7-Second Screw

Horse Sense: We'll admit we're terribly jaded, but when Mark fired up his Shelby in the Accufab shop the incredibly delicious sound tickled our pleasure center. Good thing, too, because if the bright bouquet of methanol fuel, the crackle and thunder of 1,700 hp doesn't do it for you, get your pulse checked. It's difficult to believe this beast occasionally prowls the streets.

Mark Meiering is a successful house painter from Albuquerque, New Mexico, with a thing for fast street cars. It's understandable. After a week of evenly applied Sandalwood Beige, any of us would look forward to a heavy-duty cruise scene on Saturday nights.

But as you all know, by the time a car makes it to these pages there's typically more to the story than boy meets blower and beats Camaro. In this case it's the familiar tale of a little was fun, so why not a whole lot more? Or, how to run 7s in three engines and two blowers.

He bought his GT500 Shelby new in 2007 and has "done a ton of street driving" with it. He says it was stock "about two weeks before I got bored with it," and he and a friend bolted on a Kenne Bell 2.8-liter screw blower in about 10 hours. This was KB's first generation Shelby blower. "It really woke up the car," Mark explained.-

The combination lasted about six months before a tuning issue rattled a rod through the side of the block. There was no warranty love coming, of course, so Mark had to paint a few extra bungalows before latching onto the then-new Ford GT-based aluminum 5.4 block to build a second engine around. The compression was set at 10:1 for a little extra punch and the 2.8 blower was put back on. Later Kenne Bell released the 3.6 blower and Mark had to have that. This proved a happy combination, or as Mark put it, "That was a fast street car! It was happening."

Of course, Mark was always fiddling with his by-then 10-second Shelby, and among other things, he tried a set of more aggressive cams. These were causing some issues when a friend of Mark's was referred to John Mihovetz at Accufab as a hot modular expert who could probably sort out the problem. This isn't bad advice, as regular readers may recall John has a twin-turbo 4.6 program he's developed to 2,800 hp and nearly 5-second timeslips in a tube-frame Cougar. The result was John built a motor for Mark in 2009 that made 1,100 flywheel horsepower, which you'd think would be enough. We documented this engine as part of a Kenne Bell 3.6-liter supercharger test in 2010 (Kenne Bell Twin Screw Supercharger - Bell Curve - 3.6-Liter Twin Screw). As this was the same engine that's still in the car the blower article gives some good nuts and bolts background if you're interested.

By that time, Mark was already circling moth-like to the drag racing flame as the only place to wring out this sort of "street car" is at the dragstrip. The Mihovetz engine with its Ford GT block, heavily prepped GT500 cylinder heads, and top-notch internals were ready to make truly serious power, and Jim Bell at Kenne Bell had become interested in the program as well. The goal was set to make it the first belt-driven GT500 street car in the 7s, a feat performed at a hot and humid test session at Fomoso dragstrip in Bakersfield, California, last September with a 7.817-/180.57- mph pass. Considering some of us on staff remember when it nearly took a Top Fuel dragster to run these numbers, lobbing a steel-bodied Mustang with a full interior down the quarter-mile in less than 8 seconds is fairly mind-blowing.

Key to making serious horsepower is fuel. It absolutely must be high-octane for detonation resistance, and like many today, Mark found alcohol just the stuff. For the most part this means E85 from local gas stations, but just as we were documenting Mark's ride, John Mihovetz switched the car to methanol, like his pure drag car runs. The two fuels are somewhat interchangeable. Yes, they do require different tunes, the methanol is horribly corrosive and requires careful attention to material compatibility throughout the fuel system, plus it requires even greater fire-hose volumes than E85. But it also has cooling and burning properties much closer to E85 than gasoline.

Supplying the necessary fuel volume is far beyond the capabilities of any bolt-on fuel pumps and lines. Today the Shelby wears a fuel cell and cable-driven Waterman Racing Components fuel pump. A belt drives the external dry-sump-system oil pump, with a cable running off the back of the oil pump to the Waterman fuel pump at the rear of the car. While capable of resetting your concept of how much a fuel pump can cost, the Waterman pump has proven bulletproof and easily capable of slaking the alcoholic 5.4's thirst. It's even silent, a plus for street operation.

It also takes a blower. Kenne Bell has kept the program sourced with 3.6-liter, liquid-cooled units, the better for KB to develop its largest blower currently (there's always a larger one coming…). We won't re-plow the 3.6 story here, but will point you toward the photos showing the low-restriction inlet developed on Meiering's car. It's key to getting 1,700 hp worth of air into the engine. We'll also note Kenne Bell's 3.6 Shelby blower kit is pretty much a bolt-on on Mark's car. Liquid-cooling was used, along with boost in the mid 20-psi range.

As for the core engine, it's a 5.4 using the Ford GT block—3.555-inch bore x 4.165-inch stroke—and heavily prepped GT500 cylinder heads. It's mainly the work of Fred Grouchulski at Mihovetiz's engine shop Accufab Racing Engines. While it does rev, this is no flyweight small-block, but rather a bulletproof, built-to-take-it drag motor jammed with the knowledge and hand-detailing it takes to prevail at these power levels.

To get an idea of the mechanical robustness, the engine specs include a billet Bryant crank and John's special Manley Pro Series connecting rods. Fred calls these "spark diesel rods" because they're about three times beefier than gasoline rods, hefting in at 1,900 grams worth of bobweight. Equally stout are the custom JE pistons with their 0.250-inch-thick skirts and ditto on the piston pins. It's all good to 3,000 horsepower says Fred.

Taking advantage of the high-pressure air at the base of the windshield, the big Kenne Bell aspirates via one of the shortest, least restrictive inlets possible, built by Hogan Manifolds. The idea came from a “mile car” John Mihovetz worked on, and was pushed along by Mark’s engine sucking the previously fitted Ford GT inlet tube flat at full chat. Underneath, the blower sits on the usual Kenne Bell adapter plate/charge cooler and stock Ford intake.

With the Harwood fiberglass hood attached, the twin 105mm Accufab throttle bodies show their unrestricted access to the atmosphere. For street driving, Meiering fits a custom air filter over the still drive-by-wire throttles to keep out the birds and small planes.

Using a Ford GT front cover allowed Meiering to ditch the power steering, which in turn allowed a shorter, more stable supercharger drive belt. The 10-rib Kenne Bell arrangement, which includes a Thumper tensioner, has proven trouble-free.

There’s plenty of jewelry hidden under Mark’s Shelby. The billet Dailey Engineering oil pan/stud girdle and pump assembly is something John runs on all his modulars. Another Dailey benefit, all the oil lines are machined into the pan, eliminating external oil lines.

Engine management has been something of a journey for Mark. From tuned stock hardware, he moved to Big Stuff 3. When John took over the engine and tuning, he wanted Motec controls like his own race car, so this Shelby was re-wired for Motec, which it currently runs.

Integrated into the Dailey oil pan is the belt-driven, Roots-type Dailey oil pump. Only two oil hoses are required to/from the cooler and Petersen oil tank. Another plus, the Dailey pump is designed to accept the cable drive for the Waterman fuel pump so integrating those two is a plug-in affair.

The hydrant-like fuel volumes required by high-powered alcohol cars tax the capability of electric pumps, and Mark found the pro-racing-oriented Waterman 1320 pump was the answer to popped circuit breakers and dead batteries at half track. The cable drive from the oil pump gives a wide latitude in mounting. Meiering chose under the fuel cell; here the cable drive is visible coming from the top of the photo. The pump is anodized red and black; the Magnafuel filter natural aluminum. Fuel supply is no longer an issue.

Meiering found dry-sumping a must at the 1,200hp level, as the 5.4 was snacking on bearings—he never lost an engine but dry-sumping cured all oiling issues. The harmonic damper is “the biggest ATI damper that will fit.” It requires some machining of the Ford GT front cover.

If the big Kenne Bell blower and lawn sprinkler fuel injectors are stuffing the engine full of air and alcohol, then it makes sense the headers must be huge to get it all out. Mihovetz says you can’t get them big enough; these custom 21⁄8 to 21⁄4-inch stepped primary headers are as large as will fit and still aren’t enough. For cruise nights, Mark fits four mufflers in a vain attempt to avoid choking the exhaust flow. Muffling this monster is a crime as its exhaust note is absolutely prime.

He considers this a low-compression engine at 12:1—alcohol is forgiving of high cylinder pressures—and everything is coated for reducing friction or as heat barriers. The rings are file-fit Total Seals with a tough-as-nails stainless steel upper ring. The engine was broken in on Pennzoil 5W30 mineral oil, then run on frequently changed synthetic Lucas 5W30 due to oil dilution by the rich alcohol mixtures.

John notes he's seen 50hp gains from increased header size at this power level, and Mark's engine benefits from enlarged headers. He also notes the Mustang/Shelby body accommodates only a small rear tire and thus can't handle excessive torque. So John has tried to shift the torque peak higher by widening the overlap and extending the exhaust duration in the custom camshaft grinds.

For another look at this family of engines, check out our inside look at John Mihovetz's 4.6 program (Mercury Cougar Cobra Hybrid - Mad Motor-World's Quickest Modular). A few details have changed since that '09 article. John's switched to methanol and a different chassis; it makes an additional 500 hp since our chronicle—but the general idea applies to Mark's larger 5.4-liter engine.

Speaking of articles, comparing this story to our earlier article on the Kenne Bell 3.6 supercharger as run on Mark's engine, some notable configuration changes have occurred leading to the 7-second run. Most importantly, the giant Kenne Bell Mammoth inlet was discarded in favor of a pair of even larger rear facing throttle bodies. They aspirate unimpeded from the high-pressure area at the base of the windshield, an arrangement we've long thought superior to sneaking air through holes in the radiator support or fenders.

In preparation for the 7-second attempt, the engine was dyno-tested and the car hit the chassis dyno several times. Even though most of the dyno work was quick tuning checks at reduced ignition timing and other brief, not full-rpm runs, we did get a good clue of what the engine produces: a documented 1,627 hp at the flywheel and 1,225 hp at the tires. As we just hinted, the combination makes north of 1700 hp at the track, as that's the only place the engine has been run with something approaching a hot tune. There should be a little more in it given a cool day, and Mark suspects there's a 7.60 timeslip under ideal conditions. When it does, Mark will follow his usual drill of leaving on the transbrake at 3,500 rpm and running it out the back door at 8,400 rpm.

The engine is perfectly happy; overall it's a smooth ride with the new torque converter. Things to work on are weepy head gaskets, something of a constant at this power level, and something Accufab can cure with its dry-deck trick which separates the water path between block and heads, with no water passing through the head gasket interface.

That done, we think Mark might be content to rest a bit. The road to the 7s has been longer, and more labor and fiscally intensive than he really enjoys. A man of the street, Mark finds the racer's reality tiresome. The constant upgrading, compounded by whatever custom work required because you've upgraded everything it bolts to … it's not the street with its cruising and quick blasts. But he's got a solid 7 in his pocket and it would be nice to shave a tenth off that…

One of the first sacrifices to the go-fast gods was the Shelby’s original transmission. Replacing it with this Rossler Transmissions Turbo 400 proved a good move as it’s been bulletproof. Mark wouldn’t mind having an overdrive—there is none available—but says his street driving is sufficiently limited that short gearing isn’t a major obstacle.

Key to launching the small-tire, high-torque Shelby is a sophisticated torque converter. At north of $5,600, the Neal Chance Racing NXS billet converter Jim Bell helped fund for the 7-second effort was worth every penny. Mark reports it’s looser on the hit, really locks up on the top end, and he’s not blowing through the converter any more. It looks sharp peeking out of the bottom of the bellhousing, too.

When our camera was under the car the afternoon Mark ran his 7.8-second pass, it was wearing this BMR front suspension, which Mark likes for its wide stance on the street. For the NMRA World Finals, he fit a new, lighter Racecraft suspension. The big difference is the spindles—the Racecraft has lightweight fabbed spindles that move the front track in and the ride height down a half inch.

After folding the lower control arm brackets from launch loads, Mark figured it was time to get a real rear axle and suspension. The Racecraft welded 9-inch housing, 40-spline axles and spool, plus the Racecraft suspension fit the bill. The coilovers are from Venture Motorsports.

Parachutes and license plates—for when you know you’ve gone too far but there’s no turning back.

On the street when Mark could use a little ventilation and has a bit more time to check the dials, he puts his Roush vent gauge pods to good use. Other than the water temp, air/fuel ratio, fuel level and oil pressure gauges, he has no other aftermarket instruments or datalogging. He reports the ads are true, air still flows fine with the instruments in the vents.

Inside Mark has added what’s needed and taken little out. The sound system is simply dead weight with the loud exhaust, so it’s gone, while Kirkey racing seats, a modified 10-point cage from Wolf Racing, and a Cobra Jet tach in the cluster are about all Mark needs in the 7 seconds he spends here. He admits to not seeing much more than the shift light during a pass.

On the Dyno

It's rare that we get both chassis and engine dyno data on the same combination. Unfortunately, the rpm range crossover is minimal, but that brief meeting of data does show that there is a bit of drivetrain loss when you install an engine in a Mustang. In either case, Mark's Shelby is putting down huge power.

In either case, Mark's Shelby is putting down huge power.

Nice Timeslip

Mark's ticket from his test session at Famoso dragstrip in Bakersfield, California, is more impressive when you realize it was run in 90-degree weather.

Mark Meiering contemplates the crazy ride from street to 7s.

Kenne Bell took the honor of the first belt-driven GT500 supercharger in the 7s when it teamed with Accufab and Mark Meiering. It takes tremendous power—about 1,700 hp—to cannonade a two-ton car such as this through the quarter-mile in 7.81 seconds at 181 mph.