Since acquiring our Fox-body Mustang Ultra Street chassis, we’ve been hard at work getting it ready for the new drivetrain and upgrading it from stem to stern. In this installment, we’ll take a look at the completed small-block Ford engine, the turbocharging system we went with, the FuelTech ECU, and the fuel system.

SBF to the Front

When it comes to small-block Ford performance, Bennet Racing Engines and KBX Performance have a vast amount of knowledge between the two of them, and KBX has been the driving force behind many Ultra Street competitors, as well as NMRA Renegade and NMCA Xtreme Street champion Joel Greathouse whose Mustang is powered by a turbocharged SBF.

For our Ultra Street project, there are many engine and power adder combinations to choose from, but Bennett Racing steered us towards a 9.5-inch deck-height small-block Ford with a turbocharger. The foundation of this powerplant is a Carroll Shelby Engine Company cast aluminum block that Bennett has used in grudge and X275 applications good to high-3.9-second, 1/8-mile runs. The cylinders were hogged out to 4.125-inch, and the lifter bores were also enlarged to accommodate more substantial lifters.

Complementing the 4.125-inch bore size is a 3.75-inch stroke length from a Callies Performance Products’ Magnum crankshaft to provide 400 cubic inches of displacement. Spinning on a set of Calico-coated bearings, the crank swings an octet of aluminum GRP connecting rods that have been cam-cut for more clearance at the big end for the 55mm camshaft. Bennett went with Diamond Racing pistons that feature gas porting, an anodized coating, and are made specifically for Bennett Racing’s Trick Flow Specialties 265 cylinder heads, which we’ll talk about in a bit. Wrapped in Total Seal piston rings, the slugs stay connected thanks to the use of .200-inch wall thickness piston pins which are chosen based on M1 fuel use and the expected horsepower load.

Getting A-Head of the Competition

Cylinder heads are perhaps one of the engine components where a good deal of power can be gained or lost. Bennett Racing has been using Trick Flow Specialties cylinder heads since Trick Flow began making them, and both companies have continued to refine them. For this build, Bennett chose its Trick Flow Specialties High Port 265RX cylinder heads.

Bennett starts with Trick Flow high-port raw castings and then put them through an extensive CNC-machining that includes the intake and exhaust ports, combustion chambers, and even the pushrod tubes. The intake valve seats are machined oversize and the company machines the heads for high-temp exhaust seats before installing 5/16-inch intake and 11/32-inch exhaust guides. Bennett Racing’s hard work has netted an inline-valve, small-block Ford cylinder head that moves 400 cfm through the intake port and 300 cfm through the exhaust port. And that is through its 2.125-inch intake and 1.600-inch exhaust valves.

Additional modifications to the cylinder heads include dry-decking — or welding up the water jacket holes and re-machining the deck surface to eliminate potential water leaks from a boosted engine combination such as this. Bennett Racing also performs a specific valve job for each combination with a 50-degree valve seat angle chosen specifially for this build.

Let’s Get the Valvetrain Rolling

Another engine part that can make or break an engine combination, or a track record for that matter, is the camshaft. With over 20 years of engine-building experience, Bennett Racing has plenty of time spent testing camshafts. The company has over 100 camshaft designs for Ultra Street and X275 engine combinations alone!

As previously mentioned, the Carroll Shelby Engine Company block allows for a 55mm camshaft, with the larger diameter bumpstick offering greater valve train stability and longevity. Once Bennett has chosen its cam specifications, which are kept proprietary, the company has Comp Cams perform its micro surface enhancement process to the camshaft. The extra attention to the lobes results in flatter, more durable surfaces that can withstand higher loads as they are able to more evenly distribute the forces applied by the lifter rollers.

Bennett Racing has spent considerable time designing its camshafts to maximize performance, and part of achieving that is looking at the efficiency of the valvetrain and how the components work together. Bennett has been careful to study how spring pressure affects horsepower, as running too much can rob power but running too little can allow valve float working to use the least amount of spring pressure to that gets the job of opening and closing the valves done. Getting the spring pressure just right maximizes performance and this sort of thing needs to be done with each camshaft specification to ensure optimum performance.

Bennett opted for P/N: 1254 springs from Performance Springs Inc. that have 350 pounds on the valve seat and 1,040 pounds of pressure when open. Manley Performance Titanium locks and retainers keep the springs seated and Xceldyne spring locators keep them over the valve where they should always be.

Likewise, the pushrod is a component that can be optimized as well. Too thin and too light can allow deflection in the valvetrain, while too thick and heavy can rob horsepower due to the extra mass that must be moved. For this application, Bennett Racing chose a 7/16-inch-diameter pushrod from Trend Performance that has a .165-inch wall-thickness. Having run these particular versions to 9,500 rpm, Bennett knows they are well suited to our build.

At both ends of the pushrods you’ll find Jesel components. Bennett has Jesel build a specific set of rocker arms for the Trick Flow 265 heads, and in this case, they are made from steel for extended longevity. The intake rocker is centered over the valve, but the exhaust rocker is offset to allow Bennett to fit the big 7/16-inch pushrod in the cylinder head without breaking through the pushrod tube. Providing plenty of durability and performance is a set of Jesel link-bar-style lifters that measure .905-inch in diameter.

The 400-cube Ford has a broad powerband naturally aspirated, with horsepower peaking at 778 horsepower at 7,700 rpm and 567 lb-ft torque at 6,500 rpm.

When the engine build was finished, Bennett Racing bolted-up the small-block Ford to its engine dyno for break-in and test runs in naturally aspirated form. The 400 cubic inches of Ford muscle churned out 778.4 horsepower at 7,700 rpm and peak torque of 567 lb-ft arrived at 6,500 rpm. The torque curve was broad with over 500 lb-ft available anywhere between 4,900 and 7,900 rpm.

Forget worm clamps, high boost requires a “high boost throttle body” and Wilson is one of the best in the business for creating reliable and high-flowing versions. We used a Holley billet 4500 intake elbow to mate to the Wilson 105mm throttle body from the CHI intake.

Breathing Tubes

Guiding the incoming air and fuel into the Bennet Racing Engines’ small-block Ford Ultra Street engine is a CHI intake manifold set up for fuel injection. It is topped by a billet aluminum Holley 4500 throttle body adaptor elbow (P/N: 300-254) that holds a Wilson Manifolds billet 105mm dual-seal throttle body (P/N: 471105DHB). The throttle body uses a sealed shaft, tested to 100psi to be stable under pressure and temperature. We paired it with the Ford-style throttle cable bracket (P/N: 481102) to command the throttle blade, 4-inch dual seal clamp (P/N: 486325) to connect to the charge pipe, and finally an IAC block-off plate (P/N: 481002).

For this particular engine combination, it was decided that a Chiseled air-to-water intercooler would be the best match to the Hart’s Turbo turbocharger we chose. While we intended to run the engine on E85, an intercooler would further aid in keeping air intake temperatures down when the target boost pressure and engine compression ratio were considered.

On the hot side, we used a 2-into-1, 3-inch billet merge from Shearer Fabrications to connect the stainless steel headers to the Hart’s turbo, and then it was just a matter of connecting the dots on the cold side, between the turbo, intercooler, and throttle body with a mass of aluminum tubing. The merge is not only one of the harder things to fabricate, but it can also cost you 300 horsepower if not done properly (according to Shearer). Shearer Fabrications makes the merge from 1-inch thick bar stock from stainless steel to mate to the T6 flange. We opted for the fully welded version so it was ready to go, but they also sell the flange by itself, a DIY kit with the flange and a 3D printed trace fixture to make it yourself, and even just the trace fixture by itself. These are some of the secrets to getting a bigger single turbo to spool quickly off the starting line and win championships.

Harts makes a specific Ultra Street 76mm Class Legal turbo as part of the H4 line with a billet aluminum bearing housing, backplates, and compressor wheel. The turbine wheel is 88mm and available in five different T6 turbine housings with a 5-inch V-band discharge. It also features a proprietary Dual Angular Hydrodynamic Ceramic Ball Bearing to help it spool lightning fast.

Class-Legal Boost

Pressurizing the intake charge of air for this project is a Harts Turbo piece that is legal for the Ultra Street class rules. It’s a 76mm turbocharger that began life as one of the company’s H4 product line. These turbochargers feature a billet aluminum bearing housing that is made in-house along with the backplates and compressor wheel. This unit is equipped with the new Gen-2 turbine wheel and updated 76mm compressor wheel, with an updated dual oil seal design keeping the lubrication precise.

Harts offers five T6 turbine housings to allow racers to fine-tune their turbocharger’s performance to their application. Turbine housing sizes are 1.50 A/R, 1.40 A/R, 1.23 A/R, 1.08 A/R, and .96 A/R, with all housings featuring a 5-inch V-band discharge.

Part of the Harts turbo design is the proprietary Dual Angular Hydrodynamic Ceramic Ball Bearing System. The Harts turbo weighs in at a svelte 48 pounds and the company offers a provision for a shaft speed sensor as an option.

To control boost, we used a Turbosmart GenV PowerGate60 along with a Gen V Race Port Blow Off Valve. Here you can see it connected to the Shearer merge.

Turbosmart helped round out our turbo system with the GenV PowerGate60 (P/N: TS-0555-1002). This is a 60mm external wastegate, the largest in the GenV range and Turbosmart says its the “highest flowing ‘poppet style’ wastegate in the world.” The wastegate is a critical factor in the turbo system, but often overlooked. It manages boost pressure, which means it plays a crucial role in dialing in the tune for the track. And it also protects the engine. If you want turbo system that reacts quickly to changes in boost strategy, then you need a badass wastegate.

The Turbosmart wastegate paired well with a Gen V Race Port (P/N: TS-0204-1132) Blow Off Valve to prevent boost creep and compressor surge. This little bad boy is small and light, yet flows 330 cfm. A unique locking collar and quick release V-band make it handy piece to work with. It was welded in to the under side of the charge pipe, on the straight section just before the bend leading into the throttle body. 

Streaking Toward the Big End

To get our Ultra Street Mustang project to the finish line, build-wise, we enlisted the services of Big 3 Racing in Hinckley, Ohio. There, the capable craftsman would take on the tasks of wiring, plumbing, firing, and setting the chassis up on track.

The staff began their work by taking apart the turbo system and ensuring that any and all gasketed joints were properly sealed up. To keep the driver safe, the Big 3 technicians installed a SPA Technique fire suppression system as well as fitted the parachute and safety harnesses from White Safety Equipment. Used for a variety of applications in the car, a CO₂ system was also plumbed in.

Fueling the Fun

After conversing with the folks at Aeromotive, we ordered up a number of fuel system components from them which you can read more about here. It was Big 3 Racing’s task to mount all of the hardware and connect it using PTFE hose and Russell Performance fittings. The fuel system terminated with an octet of 320 lb/hr fuel injectors from FuelTech USA.

Aeromotive’s Brett Clow calculated the hardware we would need based on an estimated 1,800 to 2,200 horsepower figure and the choice of E85 fuel. To address those needs, he chose an Aeromotive 10.0 brushless gear pump and supported that with a complement of Aeromotive and Waterman Racing Components fuel filters and regulators.

In addition to the fuel system, plumbing a racecar can also include the oiling system and that was the case with our Ultra Street build. While the Bennett Racing Engines small-block Ford is utilizing a wet-sump oiling system, we have opted to use a Peterson Fluid Systems external oil pump to lubricate the engine and turbo. The staff at Big 3 Racing connected the oil pump to the engine and its Moroso fabricated oil pan (P/N: 20529) with built-in provisions for just such an application.

Another plumbing application is the engine vacuum system and that is led by a Moroso Super Duty Pro Mod vacuum pump (P/N: 22643). Vacuum pumps are unsung heroes in horsepower, working in concert with the ring package to reduce friction losses, blow-by, and intake contamination that causes detonation. The pump was paired with a drive kit (P/N: 63885), Gilmer type pulley (P/N: 64886), and crank pulley (P/N: 97170). Big 3 Racing fabricated a catch can for any errant oil that may come along for the ride and the technicians ran the hose for this system as well as measured for proper belt length and assembled the accessory drive system, which in our Ultra Street Mustang build includes said vacuum pump and the external oil pump.

Igniting the Flame

With plenty of fuel flowing to the cylinders, it was important to have a suitable ignition system to not only light off the E85 fuel. We turned to FuelTech USA and ordered one of the company’s FTSpark 750mj ignition modules and a set of its CDI ignition coils. The FTSpark is engineered to work with FuelTech ECUs and the CDI coils are designed to be used in boosted or nitrous-oxide-injected applications where increased cylinder pressure really puts an ignition system to the test. The CDI coils were engineered to provide rapid, high-energy spark that is precisely controlled for optimum performance. Lastly, we chose to use a set of Firecore Performance spark plug wires to deliver the copious amounts of joules to the spark plugs.

Top-Level Management

Used on everything from drag-and-drive machines to Pro Mods and vehicles in between such as our Ultra Street Mustang project, FuelTech’s FT600 ECU offers just about everything a racer could ever want short of a crystal ball to see the future.

The FT600 ECU can manage a variety of internal combustion engines up to 12 cylinders, or up to 4 rotors if you’re of the rotary persuasion. It offers a massive 20 inputs and 32 outputs to be able to monitor and control a multitude of functions. It’s a ton of features packed into a relatively small aluminum case with a 4.3-inch color touchscreen that has programmable display screens to customize each user experience or application.

There are 10 LED lights that offer adjustable color and intensity. You can use these for alerts, shift lights, or anything else you can think of. The FT600 is equipped with FuelTech’s FTManager software that provides the end-user features like sequential injection and ignition, active traction control and electronic throttle control. That’s just the beginning, however, as there is an integrated boost controller, internal datalogger, progressive and PRO-Nitrous controls, and even an odometer. There’s truly way more than we can get into during this article, but as we said at the outset of this section, the FT600 offers just about everything a racer could want.

To get the most out of the tuning software, we also chose to add FuelTech’s EGT (Exhaust Gas Temperature) Conditioners. These are designed to provide precise and reliable temperature readings from your exhaust system so you can make optimal tuning changes. The more data you can use, the more opportunities you have to improve performance.

Current Affairs

With Fox-body Mustangs well past 20 years old and having attained collector status, as well as this being a purpose-built race car, it should be no surprise that the entire chassis was re-wired to supply the necessary current for all of the systems on board, many of which were never equipped by the factory.

Big 3 Racing’s customer base is largely street-oriented drag cars, but don’t let that mislead you to believe they work on hopped-up commuter cars. Sure, they cater to those as well, but Big 3 Racing has built some of the quickest and most capable drag-and-drive race cars out there. Our Ultra Street Mustang project, however, allowed the team to focus on this being a track-only build, and it centered the wiring portion around ECU Master’s PMU-16 to ditch fuses, relays, and complicated looms of wire. Not only is it easier to wire, but its more reliable and easier to diagnose if you do have an electrical issue.

The PMU-16 is a CANBUS-based, intelligent power management unit that offers 16 high-current outputs, and if you need more, you can just add more units. The company also offers a plethora of wiring options, LCD displays and more. Big 3 Racing installed the ECU, built a new wiring harness to connect all of the electronics together, and added a switch panel for the driver to control the basic functions of the car.

Final Tweaks Before Launch

Big 3 Racing still needs to finalize the wiring on the PMU and then it will be ready to prime the fuel and fire up our Ultra Street project. From there, they plan to perform a little dyno tuning, then hit the track to dial in the suspension settings. We can hear the turbo spooling already.

*Record Scratch* – Disaster Strikes

In July of 2024, Big 3 Racing had a massive fire that consumed its entire shop. Thankfully, no one was injured (or worse), but unfortunately our project was nearly at the center of the fire and was not salvageable. It was a complete and total loss.