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Hatching The Snake—Going behind the scenes as the 50th Anniversary Cobra Jet Mustangs are born

Only 68 50thAnniversary Cobra Jets are slated for production. These cars are only available in Oxford White or Race Red. Optional 50th Anniversary graphics and badging are available, and the cars sell for $130,000. We went behind the scenes to see what goes into building a factory-engineered drag car.

Written by Steve Turner

Photography by Steve Turner and courtesy of Ford Performance

Sneaking away from the bright lights of the Cobo Center where the new Shelby GT500 took its bow, we took a 20-minute ride out to a special facility. It is where bare Mustang bodies begin their journey to become drag racing machines. These are no mere drag machines, however. These 8-second machines are factory engineered. Only 68 are slated for production, and they will celebrate the 50thanniversary of a quarter-mile legend — the Cobra Jet Mustang.

Swinging the door open to Watson Racing, we are met by the beaming grin of Mike Delahanty, Product Manager Driveline & Power – Drag Racing & Circle Track Program Manager at Ford Performance, who leads us through the office into a brightly let shop whirring with activity. Acting as a tour guide for our look behind the curtain of the factory drag racer’s journey from bare shell to turn-key terror, Delahanty has plenty of reason to smile.

“There is something about Mustang that makes it different from the Camaro or Challenger. It’s got a lot of history and a lot of pride,” he reflected.” I don’t think there is a model anywhere, at least in North America, that is this vertically integrated. Think of all the different Mustang variants, and this is the best Cobra Jet we have done so far.”

For the 50thAnniversary CJ, Ford Performance created a 5.2-liter engine based on the new GT500 block and filled with its cross-plane crankshaft, Manley connecting rods, and MAHLE forged pistons. Topping the stout short-block are a pair of Voodoo 5.2-liter heads from the Shelby GT350 fitted with upgraded cams and valvetrain bits. A Whipple Superchargers Gen 5 3.0-liter supercharger provides the boost it needs for 8-second passes at over 150 mph.

Since its rebirth in 2008 to celebrate the drag star’s 40thanniversary, the Cobra Jet led the charge for a new generation of factory prepped drag cars. Now, the NMCA’s Holley EFI Factory Supercars class is brimming with Cobra Jets, COPO Camaros, and Challenger Drag Paks, but the Ford Performance team wasn’t about to rest on its laurels as the marquee’s 50th anniversary arrived, which happened to coincide with the arrival of a refreshed mainstream 2018 Mustang.

“From the very first Mustang Cobra Jets dominating the 1968 NHRA Winternationals to our modern-day racers, the Ford Performance Parts team continues to build on Cobra Jet’s success at the track over five decades,” Eric Cin, global director, Ford Performance Parts, said when the car debuted at the Woodward Dream Cruise in 2018. “This has inspired generations of Mustang fans to create their own performance machines for the street.”

Ford Performance engineers, including Ron Ewert and Andy Vrenko, developed a new 5.2-liter engine package and four-link rear suspension for the 50thAnniversary Cobra Jet. Also benefitting from Whipple Superchargers’ latest 3.0-liter Gen 5 twin-screw blower, the latest Cobra Jet was projected to be the quickest and fastest yet, delivering 8-second ETs at over 150 mph in as-delivered form.

A Car Is Born

The tantalizing promise of that performance coupled with such a significant anniversary had our curiosity bouncing off the rev limiter, so we arranged a visit to see how these strip stallions are born. That visiting two facilities around the greater Motor City area—the aforementioned Watson Racing, which builds the chassis, assembles the cars, and Performance Assembly Solutions, which constructs the impressive 5.2-liter powerplant.

Mike Delahanty, Product Manager Driveline & Power – Drag Racing & Circle Track Program Manager at Ford Performance, deserves a special shoutout for letting us behind the high-performance curtain to see the 50thAnniversary Cobra Jet come to life. You’d be smiling too if high-performance machinery, including the Cobra Jet, was part of your job.

You may be familiar with Watson Racing, because, well, the company gets out there and races with the NMCA and NMRA. Owner Chuck Watson Sr. has long campaigned various Mustangs, including his own Cobra Jet. The family company, run by his son Chuck Watson Jr., also builds and tweaks a lot of street and racing machines for individuals. However, the Watson clan is immersed in the modern Cobra Jet DNA.

In the early days, the company built as many as 15 parts for the cars, which were ultimately born at the Ford factory. However, at a pivotal point for the program, the company became far more intimately involved. This necessitated finding a new facility in which to actually build these storied machines, as the their existing machine shop and fabrication facilities simply didn’t have the space for more than the old development car.

“Halfway through the build in 2013, the assembly plant was going through some construction to add some new lines, so the Cobra Jet program had to cease and desist and find a new home right then,” Watson Jr. shared. “I think we put this whole thing together in about 10 days. We found a building and I was working around the clock. We did all the wiring and air lines. It was an old airplane hangar. It worked really well.”

Taking on the herculean task of keeping the Cobra Jet’s build logistics on track, Chuck Watson Jr. does it all with a smile on his face and a GT500 mouser under his hand. Obviously, he is a true partner in Blue Oval performance, as Watson has long built parts for production and racing Fords. From the headers on the Shelby GT350 and the hood pins on the new Shelby GT500 (sitting on his desk), the teams at Watson Engineering and Watson Racing know a thing or two about efficiency and performance.

While the build process eventually called for another move to the current Watson facility, he found one that suited exactly what his team needed to create these cars and more.

“We wrapped up the 2013 Cobra Jet build there and started the 2014 Boss 302S program in that building, and the last 10 or so cars were finished in this building,” Watson Jr. added.

Delahanty likens Watson’s efforts to those of a star wide receiver. Ford Performance throws the Cobra Jet build deep, and Watson Jr., and his team, catch it every time. His efforts are not to be discounted, as the logistics of creating, ordering, sourcing, cataloging, fabricating, and installing all the parts necessary to build an 8-second drag car from a bare shell are daunting.

“I have some pretty talented people. We put our heads together and figured out the best way to tackle this thing. We found creative ways to assemble these cars. Typically, if you go to a race shop and you want a 25.5 certified cage, it’s, on average, a couple of months,” Watson Jr. said. “We do three a week. People don’t really understand that, but it’s a tall order to do three of those a week.”

It certainly doesn’t hurt that Watson Jr. is a racer at heart, so he knows that there is balance between building these machines efficiently while ensuring that they perform at a high level.

“Anybody can make a part, but can you make 68 of them efficiently and cost-effectively?” he inquired. “To actually be able to build these cars and be able to participate and race them at the track is something to be spoken for as well.”

“These guys are part of the team that helped develop the car. There were a lot of times that we turned to Chuck and said, ‘What do you think?’” Delahanty said.

“The cars come in from Flat Rock, or FRAP as it is known,” Delahanty explained. “It’s a special-run body-in-white build with no sealer. The cars arrive in this very virgin state. What they do is batch build the cars for this program. They will run a couple each week. We will get the call that says, ‘We’ve got two bodies for you.’” When we stopped by in mid-January, Watson had a full stock of bodies in-house ready to undergo the build process.

Watson Jr. does everything from organizing all the logistics of the build process to labeling the individual cars to ensure they receive the right color in the Flat Rock Assembly Plant paint booth. The cars actually leave Flat Rock in small groups, travel to Watson Racing for chassis prep and the back to the plant for paint, which is a big ask for a facility tasked with churning out mainstream vehicles.

“Most assembly plants wouldn’t take on what they have taken on for these guys. It’s really kind of disruptive to say, ‘Hey, we want 68 cars, and by the way, we don’t want seam sealer, so turn that machine off,” Watson Jr. said of FRAP’s efforts. “We are fortunate that they are that much onboard to back it. They make trips out here to check things out and you can see the smiles on their faces just knowing they are part of it.”

With full machine shop and fabrication capabilities at its Taylor, Michigan, facility, Watson has finite control over many of the upgrades needed to convert a bare Mustang shell into a Cobra Jet. Among those key components is the 25.5-spec Funny Car cage, which is as prefabricated as it can be to expedite the installation process.

Of course, while Watson Racing cuts, welds, and bolts the cars together at a pace of three to four cars per week, the Cobra Jets are ultimately engineered by Ford Performance, so its engineers are on site there to ensure that everything goes according to plan.

“Although they are built here, the Ford engineers are here daily. The engineer responsible for those components signs off on them. So it is a thorough, in-depth process before these cars leave our facility,” Watson Jr. said.

Power to the People

As we exited the Watson Racing facility, we couldn’t help but be impressed by the attention to detail put into building these high-performance machines. The same could be said of our second stop on the 50thAnniversary Cobra Jet build tour—Performance Assembly Solutions.

You might not be as familiar with PAS, but its efforts are no less important. This company does everything from assembling superchargers and factory engines to building crate engines for several Detroit manufacturers. Much like Watson Racing, PAS uses a scaled-down assembly line process, and its tools mirror some of the tracking and computer-checked torquing used in the OE builds. However, these engines are ultimately hand-built temples of high performance infused with the spirit of their dedicated builders.

“It means everything. It tells us that, as small as we are in the big world that we live in, we do a great job. Our reputation precedes us and these engines never come back. Every one of my people on the line are gearheads,” Don Watkins, Director of Manufacturing at Performance Assembly Solutions, said. “That engine that they are building is their engine, because they are out there in the field and when their name is on that tag, that’s a lot of pride. They want to be able to say, ‘Guess what? That was me.’”

There is a myriad of parts small and large needed to build a factory drag car, and they are all stored and cataloged on these shelves. Watson Jr. ensures they always have the necessary bits on hand to complete the build, even if he has to run out and get them himself.

Though PAS has built the Cobra Jet engines for the last several years, alongside it burgeoning crate engine business, the company started small—literally, building Indian motorcycle engines with traditional tools—and has grown and modernized into a trusted supplier for the high-performance needs of the OEMs.

“We went from bore gauges and writing down all of the descriptions to air gauging. Now we don’t have to worry about the chance of errors. We just let the air gauges do the math for us to know if the bearings are going to work,” Watkins explained. “We are a small company that uses the big, OEM mentality. We can’t afford to have anything bad go out. We are big on making sure that each operation can’t go on until everything happens correctly on the prior job. We do a lot of scanning. Our touch screens show the operator how to do the engine and make sure they are doing each job.”

In all, Ford Performance and its partners come together to create a race car that is worthy of celebrating the storied history of its nameplate while pushing the performance of the S550 platform further along. It will be fun to see how quickly these cars run after being tweaked by competitive racers in the Watson Racing Cobra Jet Showdown and Holley EFI Factory Supercars classes, but their primary goal is to serve as turnkey fun for weekend racers who want a quick car without much maintenance.

“The way that these cars are delivered, you can pretty much pick them up, put gas in them and go have a lot of fun and have a very competitive car,” Watson Jr. added.

As you might expect, all 68 of the 50thAnniversary Cobra Jets are already spoken for, but if you follow along with our photos you’ll see just how a factory drag car delivers that level of performance right off the trailer.

The Watson Racing crew preps the chassis by removing the unnecessary metal; cutting up the trunk floor, from the B pillar back, to accept the four-link solid axle and fuel cell; and more.

The talented Watson welders install the funny car cage and tack in the rear suspension crossmember, which has to come out before the body goes back to FRAP for paint. The Watson team learned several tricks to making these builds more consistent and efficient, including tactical use of fixturing to hold parts in just the right place for welding.

In addition to the cages, the shock mounts, wheelie bar mount and parachute mounts are welded in, the transmission tunnel is enlarged, and the holes in the firewall are sealed off with patch panels. The Cobra Jets do retain the factory frame rails.
Once the chassis work is complete the bodies return to FRAP to go through the e-dip process, which preps the metal before paint. Then they are sprayed, inside and out, in either Oxford White or Race Red. Even the cage gets a factory paint job, and the cars look really great when they return to Watson for final assembly.

Watson techs mount the dash, console carpet, and more before raising the car to install the brake lines, front suspension, rear suspension, and plumbing. The engines are mounted on the K-member and installed from underneath.

Upon their return from FRAP, the newly sprayed Cobra Jets are bolted together. This red beauty happened to be car number two, which was ordered by Bill and Drew Skillman, who were set out having it out at the first races of the season.

A specially engineered, 5.2-liter V8 engine powers the 50thAnniversary Cobra Jets. Based on the new Predator block used in the forthcoming Shelby GT500, which features deeper 12mm head bolts for improved sealing and high-tech Plasma Transfer Wire Arc cylinder liners allow for the increase in cylinder-bore size to 3.7 inches, these blocks are better suited for supercharging than the Voodoo 5.2 blocks from the Shelby GT350 that they supersede.

As we mentioned previously, PAS fills the Cobra Jet engine block with a Ford Performance cross-plane crankshaft, a robust set of MAHLE forged pistons and Manley H-beam rods. While the latter bits are key upgrades, the Ford Performance team is rightfully proud that up to two thirds of the Cobra Jet engine’s hardware is made of production Ford parts.

During our visit, Ashley Marzouk, Engine Assembly Technician at Performance Assembly Solutions, followed the standard protocol of measuring the block, piston bores, crank bore, bearing clearance, and piston-to-block clearance. The ring gaps and such are measured with traditional tools, but done so right in the block for maximum accuracy.

Like the block, the Cobra Jet engine’s crankshaft is shared by the production Shelby GT500, which is another instance of Ford Performance’s commitment to cross-pollinating what it learns on the track to the street and vice versa. The cranks are measured and documented as well.

The rod and piston measurements are checked with high-tech air gauges, and every measurement is recorded in PAS’ PINpoint tracking software and tied a code on the block. With all this ‘birth history’ data recorded and linked, any failures can be tracked back to a particular engine and part, but thankfully such research is rarely, if ever, required because the engines are so reliable.After checking and recording all the measurements, the process continues in the mini assembly area, where phases of the engine build are broken down in the operational segments — Op. 10, Op. 20, Op. 30, etc. Here Dan Willhite, Floor Supervisor at Performance Assembly Solutions, installs piston oil squirter block-offs, lubes the mains, and installs the bearings, which are the same pieces run in production Shelby GT350s. Blocking off the piston squirters, which are designed to help the lighter duty production pistons live, is said to reduce windage, and thus parasitic drag, on the crankshaft.

Next Dan drops in the cross-plane crankshaft and uses PAS’ auto-rundown tools to torque the main caps. The he performs the first torque-to-turn test on the crank to ensure it is bind-free. Then he slides in the pistons and rods and bolts the rods to the crank with ARP 2000 bolts. Then he uses the tool to torque the rod bolts. Every measurement is checked in-process — wonky torque reading will freeze the process — and recorded into PINpoint. Once the rotating assembly is together, the builders perform the second of two torque-to-turn tests to be certain the engine is rotating freely.

In Op. 20 the cylinder heads go on. They are bolted down using the single-spindle rundown that checks the torque. Builders follow the same pattern as the factory prescribes and they also use production Shelby GT500 head gaskets and bolts. The heads wear Ford Performance cams designed for the 5.2 with a cross-plane crank and its traditional firing order. We didn’t get to witness this part of the process, as we jumped between builds, but that’s the way it goes down.

Though the Shelby GT500 heads are mechanically the same as their CNC-ported GT350 cousins, they do receive more robust valve seats. However, they weren’t readily available for the CJ build and the development showed they weren’t necessary for this application. The Voodoo heads receive upgraded titanium valves and  PAC valvesprings, which reduce valve loft and bounce, and were developed as part of the Mustang GT4 road-racing program. “These valves are about 40 percent lighter than the production valves and we have an upgrade valvespring for stability. We wanted to give the customer another feature, because we know that they to run them well above 8,000 rpm,” Ron Ewert, Engine Engineer at Ford Performance, explained.

Moving on to Op. 30, Bill Wade, Process Engineer, at Performance Assembly Solutions, adds the wiring harness after Willhite bolted up the cam covers, timing cover, ATI Performance crank damper, and such. Under that timing cover is factory chain drive bolstered by a forged crank sprocket. With the cover in place, he bolts on the oil pump, which features a billet gear set for improved durability.

Moving onto the accessory drive, Willhite bolts up the alternator and the remainder of the blower drive system. Interestingly, the Cobra Jet utilizes one of two available alternators — a 175-amp and a 200-amp unit — available on the Shelby GT350. Both are capable of revving well beyond 8,000 rpm, but Ford Performance chose the 200-amp version, which is included on production GT350s with the heated-seat option.

Here Ewert checks the belt-drive alignment with a laser tool to ensure everything lines up. This belt drive has proven to deliver prolonged belt life, numbering into hundreds of passes on a single belt. “The ATI damper is an overdrive damper, which requires decreasing the water pump pulley size for clearance. The tensioner, bracket and pulleys are all Whipple parts. They get feedback from us, based on our design work,” he explained. “We take the FEAD through a full analysis where we look at the loading of all the pulleys and optimize it where necessary and Whipple worked with us to create the system. You go out to the Cobra Jet customers at the racetracks and they’ve got the same belt that they have had on all season long. That tells you that if you design a good system the belts will survive as long as you need them.”

Nearing the end of this build, Willhite bolts on the Whipple superchargers pulley, which is designed for easy swapping in the field, should racers need to tweak the boost level.

Much like the production high-performance engines that come off Ford’s Romeo Niche Line, a plate embossed with the builder’s name adorns the Cobra Jet engine. Unlike its production cousins, these engines are assigned a single builder, but they are just as proud of their work. “It is a huge a huge honor to be part of such a pristine build. And, to be at this level, I wish my dad was still around so I could call him and tell him what I am doing, where am at, and the stuff that we enjoyed doing, I am still doing,” he said. “It means a lot. I enjoy it myself. I have been around racing my whole life and to be able to be part of this and to know that my name is out there on those engines and that I had my hands in it is huge. It’s an honor and it’s something that I will always cherish.”

While a few last details are buttoned up at Watson Racing as the engines go into their companion cars, these 5.2-liter Super Cobra Jet engines are works of high-performance art right off the line at PAS.Here is the proud team at Performance Assembly Solutions that brings the Cobra Jet engine to life. From left to right are Shawn Staniszewski, Frank Hoffman, Dan Willhite, Joey Ciarlino, Andrew Wiseley, Hayden Huggins, Ashley Marzouk, William Wade, Michael Robinson, Joshua Emrick, and Casey Henderson. If you enjoye seeing a 50thAnniversary Cobra Jet blasting down the track, you can thank them for their efforts.


Massive Mouth

Positive-displacement superchargers flourish when inlet restriction is kept to a minimum. Because the Cobra Jet runs a speed-density engine calibration, there are no limits on designing an inlet. So, to properly feed the Gen 5 Whipple 3.0-liter supercharger, Ford Performance engineers created this massive ram-air inlet, which vacuums air right from behind the car’s grille and shoves it straight down the blower’s 150mm throttle body.

In fact, the hungry blower in this car stepped up from the 132mm throttle body on its predecessor to support more airflow. This oval-bore unit sees so much flow from the massive ram-air scoop that Ford Performance engineers had to strengthen the throttle body motor to handle the additional airflow. Yeah. That’s a lot of air.

“We learned a lot from the 2016 CJ program where we were package constrained.  Unfortunately, we left some power on the table with that design and wanted to make improvements for the 50th Anniversary car,” Ron Ewert, Engine Engineer at Ford Performance, explained. “The 5.2-liter engine runs extremely cool which allowed us to shorten the radiator, and provide packaging space to route the air inlet to the grille.”

This is just one of many upgrades that serves to push the 50thAnniversary Cobra Jet to make it the quickest version yet.

Tested and Tuned

Like its predecessors, the 50thAnniversary Cobra Jet can surely be tweaked and tuned for quicker e.t.’s. It definitely provides a robust platform for competitive racers, but engineers designed this race car with weekend racers in mind. If you want to check the fluids, set the tire pressure, and rip off a quick pass with little headache, this is the race car for you.

To do so, engineers put in months of testing to ensure its durability and during that time they dialed in the combination, so it will perform consistently. It is definitely rock solid from a durability standpoint.

“We go directly from development to durability testing, or what we call DV, which is design verification,” Ron Ewert, Engine Engineer at Ford Performance, said. “We take a trace of the vehicle run in the quarter mile and plug that data into the engine dyno to simulate the quarter-mile run on engine dyno, and that includes the burnout box, the two-step at the starting line, the shift points and the cooldown after the run as the vehicle returns to the starting line.”

“Our goal is to run about 100 passes of that simulation and we do it almost back to back to back over the course of a few days, so the engine sees a lot of usage in a very short amount of time,” he added. “That simulates a very worst-case scenario, but the 100 passes simulates about two years of usage for the average customer.”

Upon completion of that testing, Ewert and his team tore the engine down, sent the crank out for Magnaflux testing, and everything was measured a verified. Everything was in great shape, right down to the bearings, which he said he would have no problem reusing.

In parallel to that durability testing, Ford Performance calibrators used the dyno and track testing to create a read-to-run Cobra Jet calibration.

“We went through a number of hours of testing and mapping that provide you all the optimum points of camshaft position,” Ewert explained. “You map all of those positions to come up with what we call a VCT schedule, which is where to park the cams at a given speed and lobe point. You optimize the position for proper combustion and so forth.”

Moreover, that calibration is designed to offer trouble-free driving in the pits, in the staging lanes, and on the return road.

“We also use a Gen1 VCT system on this car, so the intake phasers are 2011-2014. As such, our camshafts had to be phased in such a way to use their full range of authority,” Ewert said. “It also works with the 2014 control system. This way we give the customer the driveability with the VCT, which is active. It gets automatically locked down via the calibration for the quarter-mile run.”

The Details

Car Make/Model/Year:50thAnniversary Ford Mustang Cobra Jet

Engine:5.2-liter SCJ V8

Engine Builder:Performance Assembly Solutions

Displacement:317 cubic inches

Block:Predator 5.2-liter aluminum (PN M-6010-M52A)



Crank:Ford Performance forged cross-plane crankshaft (PN M-6303-M52)

Rods:Manley H-beam connecting rods with ARP2000 bolts

Pistons:MAHLE hard-anodized forged pistons with low-friction coating

Heads:Four-Valve Voodoo aluminum

Valvetrain:TiVCT with titanium valves and PAC valvesprings

Cam Type:Gen 2 Coyote 5.2-liter high-performance cams (PN M-6550-M52)

EFI System:Ford PCM with Ford Performance speed density calibration

Power-Adder:Whipple Gen5 3.0-liter twin-screw supercharger with 150mm throttle body

Headers and Exhaust:Kooks long-tubes

Transmission:Three-speed automatic racing transmission with SFI safety housing

Transmission Builder:Joel’s On Joy

Torque Converter:Joel’s On Joy 8-inch

Rearend:Strange Engineering 9-inch solid

Body and/or Chassis Builder:Ford S550 with Watson Racing SFI 25.5-spec Funny Car roll cage

Suspension (Front):Double-ball-joint independent with double-adjustable coilover struts

Suspension (Rear):Four-link with antiroll and Panhard bars

Brakes (Front):Strange Engineering low-drag disc system

Brakes (Rear):Strange Engineering low-drag disc system

Wheels (Front): RC Components 50thCobra Jet Anniversary Comp Series Torx

Wheels (Rear):RC Components 50thCobra Jet Anniversary Comp Series Torx

Tires (Front):26×4.5×15-inch Mickey Thompson ET Drag skinnies

Tires (Rear):30x9x15-inch ET Drag Pro Drag Radials



Ford Performance

(800) 367-3788


Performance Assembly Solutions

(734) 466-6380


Watson Racing

(855) 928-7223