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Drag Suspension Test - Forward Progress
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In most cases, e.t. and speed are the primary focus when we perform tests taking Mustangs from Points A to B on the dragstrip. However, for this project, we decided to put those two criteria on the back burner and center our research on collecting quantitative data (using a Motec ADL3 datalogger) to see the differences in our Mustang’s launch characteristics when the car is outfitted with street/road-race suspension gear and street/strip hardware. Maximum Motorsport’s owner, Chuck Schwynoch, and his team (Engineering Manager Luka Dugandzic and Tech Specialist Jack Hidley) have been most helpful when it comes to recording data and tuning a ’Stang’s suspension based on that info. Team Maximum provided outstanding trackside assistance for our entry in the 2010 Castrol Syntec Top Car Challenge. Their collective knowledge and suspension calls helped us secure a Fourth Place finish in the competition. After outfitting our ’Stang with the datalogger and making runs over the course of two test sessions, the data (results) showed us areas of inefficiency when stiff, road-race-specific components were on the car, and how the same launch variables improved when changes were made. The important thing we learned from this project is that setup is critical to various Mustang-performance applications. Simply bolting suspension parts on your Pony is one thing. However, when parts are designed for a specific use, their optimum performance will only come through testing and collection/analysis of data (using timeslips or a datalogger).  Maximum Motorsports’ owner,...  Maximum Motorsports’ owner, Chuck Schwynoch plugs the Motec ADL3 data-logger harness into the ’Stang’s factory wheel-speed sensor connector on the driver side. The logger measures acceleration in the fore/aft, left/right and up/down directions.  Our baseline tests at Fontana...  Our baseline tests at Fontana were made with the Pony’s suspension still in its Mojave Mile configuration (set up with corner weights being equal all around, for optimum handling and stability). In Las Vegas, Chuck decided to raise ride height approximately 2.5 inches. Increasing height raises the center of gravity, which increases weight transfer for a given acceleration. Increasing weight transfer to the rear tires promotes good traction and thus generates harder, quicker acceleration. Secondarily, raising the rear of the car also limits the amount of rebound from the tires, and ultimately keeps them from spinning. A ½-inch-drive ratchet is all that’s needed to make jack-screw adjustments on Maximum’s drag-race lower control arms.  End-links for the adjustable...  End-links for the adjustable rear sway bar and Panhard bar were equipped with strain gauges affixed to their rod ends. The strain gauges allow the ADL3 to record the tension and compression loads on each bar, giving us valuable information about the Mustang’s body roll at launch. We ultimately want the body roll to be fairly low, less than 1 degree. This type of data will give us a guideline on how to adjust the ride height to optimize roll angle. End-links for the adjustable... End-links for the adjustable rear sway bar and Panhard bar were equipped with strain gauges affixed to their rod ends.  The strain gauges allow the...  The strain gauges allow the ADL3 to record the tension and compression loads on each bar, giving us valuable information about the Mustang’s body roll at launch. We ultimately want the body roll to be fairly low, less than 1 degree. This type of data will give us a guideline on how to adjust the ride height to optimize roll angle.  Wheels and tires became one...  Wheels and tires became one of our big concerns with this project. We knew that the rears would be downsized to 15s, but there isn’t a 15-inch front-runner on the planet that will clear the big six-piston Wilwood binders on our Pony’s front end. Race Star Industries’ 92 Drag Star front wheels (17x4.5-inch, available through Latemodel Restoration Supply) make brake-caliper clearance a non-issue. When paired with M&H Tires’ Racemaster 26x4.5x17-inch front-runner/skinny front tires (DOT certified, available through Summit Racing Equipment), all the bases are neatly covered.  We completed the Mustang’s...  We completed the Mustang’s wheels package with 15x10-inch 92 Drag Stars for the back. The rear wheels’ 6.5-inch backspace allows perfect fitment of Mickey Thompson’s ever-popular 28x10.5-inch drag slicks on ’99-’04 Mustangs with stock-length rearends.  For hard-core competition,...  For hard-core competition, installing Maximum’s new drag-race rear sway bar (1.25x.025-inch) provides more than 2.5 times the stiffness of the street piece.  For hard-core competition,...  For hard-core competition, installing Maximum’s new drag-race rear sway bar (1.25x.025-inch) provides more than 2.5 times the stiffness of the street piece.  In street/road-race trim,...  In street/road-race trim, our project ’Stang leaves the starting line without any weight transfer to speak of, which results in spinning and/or hopping rear tires. Notice how wide the separation between tire and body is at the back of the car.  This is the data log from...  This is the data log from our first pass with the race-suspension pieces installed, and the 17-inch wheels and tires. The key data points are engine speed (rpm: red trace), acceleration rate (Gs: orange trace), wheel speed (mph: pink and light blue traces) and throttle position (green trace). What’s interesting to note is that while we still experienced some tire spin and then severe engine bog with this setup, the ’Stang still pulls 1.4 Gs on this launch—our best during this initial test session. (See datalog enlargement at 50mustangandfastfords.com.)  When using slicks and Maximum...  When using slicks and Maximum Motorsports’ drag-race suspension pieces, the Pony’s initial torque severely wrinkles the sidewalls, and actually lifts the right rear tire and pushes down harder on the left slick. To compensate for this, we adjusted the corner weights to put about 250-in/lb more weight on the right rear, ensuring that when KJ dumps the clutch, there is equal weight on both rear tires, which gives the most forward traction possible. As the car accelerates and weight transfers from front-to-rear, the front end extends (bringing the tires about two feet off the ground) as our ’Stang gallops forward and the slicks start to return to their original shape due to centrifugal forces and reduced engine torque.  When using slicks and Maximum...  When using slicks and Maximum Motorsports’ drag-race suspension pieces, the Pony’s initial torque severely wrinkles the sidewalls, and actually lifts the right rear tire and pushes down harder on the left slick. To compensate for this, we adjusted the corner weights to put about 250-in/lb more weight on the right rear, ensuring that when KJ dumps the clutch, there is equal weight on both rear tires, which gives the most forward traction possible. As the car accelerates and weight transfers from front-to-rear, the front end extends (bringing the tires about two feet off the ground) as our ’Stang gallops forward and the slicks start to return to their original shape due to centrifugal forces and reduced engine torque.  When using slicks and Maximum...  When using slicks and Maximum Motorsports’ drag-race suspension pieces, the Pony’s initial torque severely wrinkles the sidewalls, and actually lifts the right rear tire and pushes down harder on the left slick. To compensate for this, we adjusted the corner weights to put about 250-in/lb more weight on the right rear, ensuring that when KJ dumps the clutch, there is equal weight on both rear tires, which gives the most forward traction possible. As the car accelerates and weight transfers from front-to-rear, the front end extends (bringing the tires about two feet off the ground) as our ’Stang gallops forward and the slicks start to return to their original shape due to centrifugal forces and reduced engine torque. Here’s the data log from the ‘Stang’s hook-and-book launch with Maximum’s drag-race suspension, and lightweight wheels and tires on board. Notice how despite this also being a (peak) 1.4-Gs launch, all of the traces start much quicker and are more aggressive than those in our street-trim graph? Th  When it comes to making a...  When it comes to making a complete and totally clean pass down the dragstrip, the dark cloud of parts breakage continues to hang over our heads. After discovering axle damage and thrashing to get our test ’Stang ready for testing in Las Vegas, we proceeded to destroy this 4.30 ring-and-pinion set during our first pass in Sin City with Maximum’s drag-race pieces installed. Thanks to great assistance from fellow racers and a local driveline shop, our Pony returned to action with a set of 3.73s. Of course, the gear change brought about a huge change in the car’s launch/60-foot potential and overall quarter-mile performance, so our focus in this effort is to examine what’s happening (data wise) at the release of the clutch. 5.0
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