5.0 Mustang & Super FordsHow To Engine
Two-Valve Modular Motor Project - Letter-Perfect Power
ATI, D.S.S., JLT, and SCT Score An "A" in our Two-Valve GT Test at B&D
Horse Sense: As ProCharger's F-1 series of race superchargers goes, the F-1A unit that we're using on our '02 'Stang can be considered a mid-level player in the lineup. Up first of course is the F1, followed by the F-1A and F-1C units-with the only difference between the A and C being a bigger compressor housing for the C at 9.75-and, of course the F-1R, which creates such a tornado that it shouldn't even be considered unless you're working with an engine of 400 cubes or better.
If you're a diligent 5.0 Mustang & Super Fords reader, no doubt you're aware of the various project cars we've worked on over the years. Maybe you've even picked a favorite in the lot of them.
Looking back, there's been Project Mondo Stocker, Dr. Jamie Meyer's 8-second LX coupe; Editor Turner's recently sold Real Street '89 notch, inspired by the NMRA class that bears its name; Associate Editor Johnson's Roadkill, a still-under-construction '91 LX that's gone from four-banger to Four-Valve with a Vortech T-trim blower to boot; and more recently, your tech editor's Project T-top Coupe, a street-bound '86 T-roof notchback that runs 9s with the stereo crankin'.
While all of those project Ponies stand on the Fox platform, believe it or not (again, loyal readers already know this), we also have a New Edge stallion in our project-car stable: the '02 Mustang GT of Crystal Jones, your tech editor's more-than-understanding wife, who has given us "no-restrictions" permission to experiment with her 'Stang-Crystal's first-ever, dealer-new car-in our never-ending mission to bring you new and cool Mustang technology.
That's right; we've actually had an in-house modular of the Two-Valve variety for quite a while now. The initial plan was to use our '02 GT to test, evaluate, and showcase basic bolt-on enhancements for '99-'04 'Stangs, and we did that with projects such as a Bullitt brake-and-wheel upgrade ("Becoming Bullitt," Feb. '06, p. 84), and an exhaust/pulley/CAI/plug-in tune installation ("Volume Two," May '06, p. 80). However, as is the norm for most enthusiasts, the yearning to make a major performance change eventually overcame us.
To satisfy our curiosity about an easy way to increase a stock 4.6's horses, we added ATI ProCharger's P-1SC Stage 2 supercharger system and an Accufab throttle-body/plenum combo to our project car ("Beyond Bolt-On," June '06, p. 78). In addition, Saul "The Surgeon" Gutierrez of Extreme Automotive in Canoga Park, California, DiabloSport-tuned a safe 383.52 hp and 372.32 lb-ft of torque to the rear wheels of Mrs. Jones' New Edge on 91-octane pump fuel and 9.10-psi of intercooled boost.
We realize our final power number for the project was well below the 425-or-so pump-gas horses that can be achieved with predominately stock Two-Valve modulars. Our goal was to make good, safe, low-boost horsepower for daily street use, not find the breaking point. That same stock engine, which subsequently was removed with approximately 45,000 original miles, is still strong as ever and powering another 'Stang.
You're probably asking, "Why remove a setup that's working perfectly fine, especially when it's in your wife's Mustang? Are you crazy?" Well, we won't comment on our mental state, but one of the main reasons we do some against-the-grain projects is because we firmly believe that making good 'Stangs better is a big part of this hobby of ours.
From a true gearhead's perspective, making a 'Stang better means increasing horsepower and torque. While power gains are achievable through many different processes, one thing is consistent: When your plan is to make power that's beyond the limits of a stock block's capabilities, a good engine (iron block, forged rotating assembly, and so on) is mandatory. We commissioned D.S.S. Racing to set up one of its Super Modular 4.6 long-blocks for the next leg of our Two-Valve power project; the details are in our Nov. '06 issue ("Big-Boost Bullet," p. 100).
Our D.S.S. engine's Level-10 race-prepped block is stocked with an '03-'04 Cobra forged crankshaft; 4340 H-beam rods; and D.S.S. Pro-X Max-Wedge dished pistons that make 9.5:1 compression. The short-block is topped with D.S.S. CNC-ported cylinder heads, Anderson Ford Motorsport's F-62 camshafts, and Professional Products' Typhoon intake manifold, upper plenum, and 75mm throttle body.
Note that although we stayed with an ATI-ProCharger for the blower upgrade, we chose to completely bypass the company's D-Series unit (D-1SC)-a more-powerful and still-streetable (but not smog-legal) upgrade that can easily make upwards of 600 hp with race fuel and proper tuning. We instead planted our feet on the first rung of the race-specific blower ladder, installing ProCharger's F-1A supercharger system (featuring a cool, eight-rib drive-belt conversion by House of Boost) to see if we can find a peaceful coexistence between hard-core race equipment and our daily driven 'Stang ("On the Brink of Insanity," May '07, p. 166).
As it is with life, a radical project like this one isn't always the proverbial bed of roses that we'd like it to be. While we put in our new engine and big blower with little problem, making a tune that would get the combination to work together in streetable harmony as a blow-through system (mass air sensor is located inline, after the supercharger) proved to be quite the challenge, full of frustration and delays.
Our decision to convert the supercharged engine's airflow system to "draw through" (air is drawn into the mass air and processed before it enters the supercharger) has proven to be a wise move. With the draw-through setup, B&D Racing's Brian Schapiro was able to create a pump-gas tune that allows us to cruise our project 'Stang anywhere without apprehension, and easily spin the chassis dyno's rollers to the tune of 484.17 hp and 414.08 lb-ft of torque-for now-at just over 6,000 rpm. Combine the tuning nuances with a few mechanical issues (not any person's or product's fault) that required removing the entire works twice, and you'll have a better idea of why it's been such a long while since we brought you a report about this particular project.
But, as we've said in other project reports, quitting isn't in our profile. As time permitted (more than two years by the time you read this), we forged ahead with our F-1A street car effort, and now we have finally reached a point of major accomplishment. Props go to Brian and B&D's lead tech Mason "Mase" Rowland for their tenacity and dedication to the cause, especially when the going was the roughest (engine removal number two).
Big thanks to the folks at Anderson Ford Motorsport, ATI ProCharger, House of Boost, D.S.S. Racing, L&R Automotive, JLT Performance, and SCT for everything they've done in support of our outside-the-box project.
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ON THE DYNO
Our dyno session can only be described as a true flog. In two days, we put a total of 30 runs on the Super Modular 4.6, and it didn't miss a beat. Of course, half of the pulls proved to be somewhat for naught after we discovered our mass air issue, but a comparison of data for our limited-rpm pulls and those of the OEM Two-Valve shows that the new Super Modular 4.6 makes quite a bit more steam (without boost) than a stocker.
To give you an example of this, the original Two-Valve pumped out peak horsepower of 266.78 at the tires at 4,209 rpm and peak torque of 240.58 at 5,091 rpm. Using approximately 4,200 rpm as a constant for horsepower and torque, and with the F-1A in place but not effective, power was increased to 293.03 and torque rose to a whopping 364.60 lb-ft. We attribute the gain to the D.S.S.-ported cylinder heads, which flow volumes more air than stock PI castings, as well as to the F-62 cams, which keep exhaust valves open longer.
Without even being close to full fury (peaks of 6,200 rpm and 14 psi of boost), our Two-Valve GT rocked the rollers to the tune of 484.17 hp and 414.08 lb-ft of torque with perfect air/fuel, 11.7.
"The F-1A doesn't really start working until 4,500-5,000 rpm," says Brian. "The power it made at 14 pounds of boost with our limited-rpm tune tells me that with the small blower pulley and race fuel at 20 psi, a Two-Valve engine could potentially make nearly 1,000 hp at the wheels-if the block and internals will support it.
One thousand ponies...hell, even six hundred horses. Is this too much power for a daily driven street 'Stang? Well, in our case, it's not so much a too-much-power scenario (after all, our other project street 'Stang makes 830 hp) as it is a too-much-blower situation.
From the outset, our goal for this project was to see if we could somehow corral the force of ProCharger's F-1A supercharger by making the race-specific blower work efficiently in a street-driven, fully accessorized New Edge Mustang. As the numbers show, the supercharger certainly works, and works well from a power perspective. However, even with a good tune for drivability and limited-rpm performance, this setup ultimately does not have all of the street manners that we hoped to create. That's not to say we won't build more cruising-speed smoothness into the tune once we make the mass air upgrade. Conventional wisdom and general optimism tell us that everything will be perfect once air is being properly processed.
What have we learned from all of this? Well, the bottom line is that if we had a chance to do this over again, we probably would heed the suggestions of several colleagues (and even the folks at ProCharger) and install a D-1SC Stage 2 system on our '02 Pony. The "D" is definitely a rowdy blower in its own right, and is plenty capable of producing power that is close to horses and torque we hope to finally achieve with the F-1A. But, if your one and only mission is to be the biggest dog on the street with your Two-Valve 'Stang, hanging the racebred "F" on the front of your block will definitely earn you that status.
Fighting the Furious Forces...All of Them
As it is with almost any against-the-grain power-adder project, tuning an F-1A-blown Two-Valve isn't as simple as plugging in a flash tuner and downloading a premade tune.
Brian Schapiro is the resident tuner at B&D Racing in Canoga Park, California. In creating a custom tune for our heavyweight application (SCT's Advantage III program is the tuning software of choice at B&D), Brian will use our engine's air/fuel values (recorded by a wideband O2 sensor) and a value SCT calls "MAF A/D counts" (the product of mass air sensor voltage times 205) to calculate adjustments for the MAF A/D counts in order to create an optimum distribution of fuel. The goal is for the supercharged engine to make the most efficient, detonation-free horsepower and torque possible on 91-octane pump gas.
Theoretically, a draw-through mass-air system is easier to tune than the streetable blow-through tune we originally hoped to achieve. However, after making the change to draw-through, the furious windstorm that the F-1A generates showed us that even this intake-air system has its tuning challenges.
After several dyno pulls that yielded the same result-an immediate 12.0-12.6 lean spike at 6,000-6,300 rpm-and after our futile attempts to straighten out the ratio by adding fuel (raised fuel pressure and steadily adjusted fuel map by dialing in 10 percent increments, yet still seeing air/fuel numbers of 12.3 and higher at 5,800 rpm), we determined that the big blower apparently overwhelmed our setup's mass air sensor to the point where it couldn't keep up with the mass of intercooled air. While the meter was not being pegged in terms of voltage, it was nonetheless unable to measure airflow and, in a sense, signaled the processor to shut down, causing a severe lean condition at 5,800 rpm.
It was suggested that we step up the blown GT's intake-airflow system with JLT's massive 110mm S197 mass air housing and a Ford GT sensor. It's a simple enough change, and we've set the wheels in motion to make it. Unfortunately, our effort fell behind the eight ball a bit, and we didn't receive the big housing in time to push forward with our dyno tuning and still meet the deadline for this report.
However, we are confident that we're on track for increasing our Two-Valve's rev limit by another 1,000 rpm, creating a pump-gas tune that will easily put our 'Stang in the high-power zone without compromising the smoothness we want for daily driving.