ATI now manufactures approximately 500 different damper combinations. For an externally balanced engine, there is only one damper available for each application. For an internally balanced engine, however, we have a variety of choices. Just like everything else in racing, if you are looking for maximum performance, you need the right part for the right application. ATI dampers are available in many different weights and sizes. Just provide your ATI sales specialist with some general information and they will be able to tell you which damper would best suit your needs.
Make sure that your ATI Super Damper has the proper press fit. If the damper is too loose on the snout of your crankshaft all of your engine’s harmonics will not transfer to the damper and allow it to do the proper job. For best results, use a damper installation tool when you install or remove your damper.
If you have had your damper for nearly 10 years, you should send it in to have the rubber O-ring inspected and changed. ATI will also check for any problems with the hub and other damper components. We can have your SFI damper re-certified if necessary. Please speak to your ATI technician for further information. If you are racing in any sort of pro class or have over 800 horsepower, you should consider having your damper rebuilt at the end of each season. Remember, the smaller the damper you run on your car, the harder it has to work to protect your engine!
Yes! ATI’s engineers can custom manufacture an ATI Super Damper to fit almost any application. If you'd like us to make a damper for you, contact our sales department and talk with one of our damper techs. In some cases we will need you to supply us with a stock damper for measurement. We have made dampers for all types of engines, from Ferrari & BMW to John Deere and Massey Ferguson.
No! Never use your damper retaining bolt to hold any pulleys or accessory drive equipment. The damper retaining bolt should be used only for bolting the damper to the crankshaft. The damper must be banked on the crank gear and must remain tightly secured in order to function properly. When you use a long bolt or stud in an attempt to hold accessory drive components and your damper, the damper will usually come loose and walk around on the front of the crank. This will quickly result in damage to the keyway in the crank hub, the key in the crankshaft, and possibly the crankshaft. Accessory drive components should be registered on the damper face to prevent run-out and they should be retained using the pulley mounting bolts.
No! Many people think you can simply remove the weight and the damper would be okay for an internally balanced engine. This is an incorrect assumption, however. Due to the design of the damper, when the weight is removed the damper will not function properly and could potentially damage your engine. Send your damper to ATI and we can convert your damper from externally balanced to internally balanced.
The part number is not stamped anywhere on the damper itself. All of the part numbers you see stamped on the damper are for the individual parts that comprise the damper as a whole.
The flat head countersunk bolts used in ATI’s Super Dampers require a T40 Plus Torx Bit. If you are trying to source one yourself, this bit is also referred to as an IP40 Torx Plus Insert Bit. Do not use a standard T40 Torx bit as it will not work and ultimately strip the head. Remember! You must install, torque and Loctite® all bolts supplied with your Super Damper regardless of whether or not you are bolting a pulley to the face of the damper.
No! Utilizing a detailed database of converter combinations and specifications, ATI keeps detailed records of your converter’s internal dimensions, build heights and other necessary information. The converter is then rebuilt to the exact specifications as before, unless you request a dimension change.
It is best to check with an ATI representative before making the change. Something as simple as tire size can affect torque converter performance. Gear ratio, stroke and cam timing are the three major changes that will alter flash characteristics. If you purchase another car, engine or transmission, your torque converter can be sent back to ATI to update it to the new specifications. If you switch from a Powerglide to a Turbo or Turbo to Glide, the splines can be changed inside the converter. You will need all the specifications on the new combination before ATI works on your converter.
ATI torque converters have serial numbers stamped across the snout of the converter (the part that goes up against the back of the crank). Note: In January 1, 2015 ATI started stamping the number on the side of one of the mounting pads so the customer can see the number when it's installed in the car.
Any other numbers stamped on the converter are foreign numbers and usually mean that another manufacturer has worked on the converter.
With the advent of affordable 4-1/4”, 4-3/8” and 4-1/2” stroke big block Chevy cranks, and the resulting increases in torque and horsepower, has come the increasing need for more efficient converter designs. If your current or future engine combination is based on a long stroke crank, don’t forget that the torque converter may need to be modified or changed to harness the additional power.
In order to check your torque converter’s stall speed, put your vehicle in high gear and drive the car at 1 to 2 miles per hour. Push the gas pedal to the floor and note your flash on the torque. This is the same as your stall speed. DO NOT DO STALL TESTS ON CARS EQUIPPED WITH TRANSBRAKES. When speaking with your ATI sales rep or distributor, be as succinct as possible regarding stall speed and your converter. To converter builders, stall speed and flash mean the same thing. If you ask for 4500 stall, this means if you flash your converter from idle, it should go to approximately 4500 rpm. For example, a 4500 torque converter in your car will probably only footbrake to 3000 rpm before moving your car depending on the quality of your brakes. Furnishing as much information as possible to your sales rep ensures that you get the correct product you are looking for.
No!! ATI strongly recommends that you do not conduct stall tests. Stall tests break parts, and not just converter and transmission parts. Remember, you are at Wide-Open Throttle (full power) and maximum load. The pistons, pins, rods, and crank will really take a beating.
Many racers ask why it is okay to leave the line at Wide-Open throttle, but not okay to do stall tests. The difference is this – when at the starting line at wide-open throttle, you release the brake and the RPMs accelerate from that point. In the converter, the stator is locked via the clutch assembly (sprag) and goes from maximum load in a controlled constant reduction in force to zero load (free wheel) as the car accelerates. The hydraulic forces in the converter are directed in a smooth and efficient manner for maximum torque multiplication and flow for adequate cooling. When performing a stall test at wide-open throttle (or even with a rev limiter such as the MSD Two-Step), you lift off the throttle and the RPMs, now at 5,000 or 6,000, get jerked down to idle. The stator and clutch assembly goes from maximum load and torque multiplication to zero load in an instant. The clutch is unloaded rapidly and the hydraulic forces are instantly disrupted into unknown flow paths due to the rapid reduction in torque.
We have seen many converters damaged by this rapid unloading when a ring and pinion, planetary gear set, or input shaft fail. The rampant hydraulic pressure actually breaks the pump blades (fins) completely off the converter pump.
It is for this reason that converter manufacturers have for years warned against “snagging the slicks” coming out of the water as RPMs can go from 5,000 or 6,000 to an idle as the tires catch. Once again, damage can be done to the sprag assembly. Also remember that the converter builds up a tremendous amount of heat in a short period of time. By not running an engine after a stall test, all that heated fluid lays in the converter without having a chance to go through the cooler. Excessive heat eventually “fatigues” the metals in the converter.
So, just say no to stall tests. They damage parts. Use the transbrake ON THE STARTING LINE ONLY – not in the pits, not in the driveway, not for your burnouts – AT THE STARTING LINE ONLY! Your cost per run will diminish significantly.
Stall speed is affected by engine size, stroke and even camshaft duration. Small changes in engine combination can change the stall speed. At ATI, we custom design each converter to your needs. With the exception of our 10, 11, and 12-inch street converters, each race converter is hand built one at a time for individual applications.
ATI recommends Type F in all Powerglides and Manual Operation TH350, TH400, TF904, TF727, C4 and C6 units. If you are a Street Rodder with under 450 HP then fresh Dexron Mercon 3 is a fine choice as well. ATI only recommends Super F if you want to run a Full Synthetic transmission fluid. If you are running a turbocharged or high horsepower engine, consider using ATI’s new 30 weight Max Duty Super F ATF. It’s a 100% mPAO based synthetic and provides better lubrication than straight hydraulic oil. Great for Hyrdamatics, Powerglides, C-4s, C-6’s and Torqueflites.
Yes. The information your racecar shares with you is highly dependent upon the gauges you install. Two commonly overlooked, but very informative gauges, are transmission temperature and transmission pressure.
Transmission temperature is important in determining that sufficient heat has been built to send the car to the starting line. Over time, a range of average operating temperatures can be established for “before run” and “after run” readings. Transmission temperature can be an important factor in your search for ultimate performance and/or consistency. Any excessive high or low temperature condition should be noted, and might help to indicate a present or future problem.
The addition of a transmission pressure gauge can not only reinforce what the temperature gauge is telling you, but also provides information about instant damage, and normal operating wear occurring in the transmission.
For a transmission temperature gauge, look for one offering a high range of about 225-250 degrees. Ideally, the sending unit should be located in the pan to provide the most stable source of temperature. If a dedicated transmission pressure gauge is not available, an engine oil pressure gauge offering about 200PSI will work well. Most popular transmission used in drag racing, both late and early, have pressure sources that are ideally suited for this purpose. While originally provided for temporary dealer diagnostics, it can also be plumbed to provide a permanent information source. Your ATI technician can supply you with further details.
One of the most effective improvements that a performance street vehicle can utilize is a lower first gear set for the transmission. When such a 2.75 gear set is installed in a T400, T350, C-4, C-6 TF-727 or TF-904, it allows a conservatively geared 3.50 ratio car to launch with the potential of a 3.90 rear gear. Likewise, when a 4.10 rear ratio is present, the 2.75 low gear allows the car to accelerate with much more aggressive potential of a 4.56. Highway RPM in third gear is unchanged from stock. These gear sets have shown as much as a 3 tenths improvement in overall ET – often half of which occurring in the first 60 feet.
The clearance between the transmission and the flexplate should be checked on every torque converter when it's installed. Clearance should be a minimum of .100" but no more than .175" throughout.
Never install dry friction materials! Always soak clutches and bands for at least 30 minutes prior to installation. Soaking allows the friction materials to be fully impregnated with oil preventing glazing while adding to the life of the friction material.
It is critical to maintain a straight centerline from your engine crankshaft through to your converter and transmission. If your transmission and converter are NOT centered, internal parts may experience costly premature wear. Factors that cause misalignment include engines that have been line-bored with the crankshaft sunk in the block, flexplates and converters that are out of round or unbalanced or even a flexplate that does not “flex”. Internal converter and transmission components must be bored to center themselves in line with the engine crankshaft.
In stock applications, a transmission operating at 150° to 175°, offering a service life of 100000 miles, has its range cut in half when the temperature increases to 195° to 200° At 295° service life falls to only 1500 miles! In specific terms, varnishes form at 240°, seals and sealing rings begin to harden at 260° and friction plate slippage is unavoidable by 295° At 350°all seals and clutches totally burn out and conventional fluid solidifies to form carbon. Synthetic fluids offer higher heat resistance to thermal breakdown, but no better protection against failure of the internal components at the stated temperature levels.
Warming up a “bodied car” can hurt the tailshaft bushing in a Powerglide. This bushing is only splash lubed and will quickly run dry with the back end of the car up in the air. If you need to warm up the car, take it for a drive through the pits – your tailshaft bushing will thank you for it.
Always check your transmission fluid level after thoroughly warming up the vehicle. Levels will read much higher when warmed than when cold. With your car on jack stands, run it through each gear and reverse. Then put in neutral and check at idle. Right in the middle of L and F is perfect.
There are five things that could keep your transmission from moving in any direction
1. Pressure regulator valve in the valve body is stuck open
2. Broken front pump gear
3. Broken Input Shaft
4. Sheered splines in the torque converter turbine
5. Pin on the linkage that moves the manual valve in the valve body is out of the slot on the valve, and not moving the valve to direct pressure to the band or clutches. To verify pressure, remove a cooler line and start the motor and see if the pump is pumping fluid. If it is, pull the pan and check that the manual valve is moving with the shift linkage.
Check your shifter cable in each gear! Not all “shifter to bracket to transmission” installs will line up perfectly in EVERY gear. This will cause burnt clutch packs in the gear that is not fully seated!
When using an aluminum drum in your Powerglide transmission, it is important to change the fluid and filter regularly as well as check your band adjustment. Aluminum is lighter in weight but it also wears very quickly. A regular fluid flush and filter replacement can extend your aluminum drum life significantly. Also, always use a red-lined band with an aluminum drum. Kevlar will tear the drum up in short order.
The line pressure of a transmission is the “life blood” of the transmission and is just as important as oil pressure for a motor. You should monitor the line pressure on every tranny you use.
Rust can be a real killer when storing transmissions and converters for long periods of time. Be sure to store your units in a dry, well ventilated place with all holes capped and plugged!
1. Transfer power from the converter to the input sun gear while in low gear.
2. Transfer power from the converter to the high gear hub in high gear.
3. Direct oil coming from the converter to the front ring on the shaft and out through the pump to the oil cooler.
4. Direct oil from the cooler between the 2 rings and down through the center of the shaft to lube and cool the direct clutches, gear set, output shaft bushing and the entire transmission.
5. Maintain proper oil pressure in the converter and cooler with its sized holes that are “downstream restrictions” to control the flow out of the converter.
6. Center and support the Input Sun Gear from its pitch diameter to the ½ diameter that goes into the bushing on the output shaft
7. Center and support the Output Sun Gear (flange gear) via the “wedding band”
Which companies in the industry are capable of making input shafts properly? Who has the hobs, shapers and cutters to cut splines? Do they have the machines and the expertise that is required to manufacture this critical part? Can they properly heat treat it, straighten and finish grind it? Or, do they just buy it from someone and resell it? One thing is for sure: at ATI, if we have a problem, we have a REASON, not an EXCUSE, because we make it in-house from start to finish. We find the problems, not you. The bottom line is simple: Manufacturing technique for this product is critical. Material is critical. Heat-treat is critical.
Always look for a converter to be full (generally about a quart +/-) before installing on the trans. Likewise, always fill the transmission with approximately 4 quarts of fluid +/-. And don’t forget the engine, rear, etc. It’s easy to do after a new build or rebuild when everything is reinstalled and ready to go.
Drive shaft rpm x gear set ratio = total rpm / engine rpm=percentage of slip. If you have a converter that is “too locked up” it stops pulling on the engine and the car suffers from spinning on the gear change. This is because the converter needs to pull on the engine thereby producing horsepower. When a converter is “too locked up”, the horsepower falls off so when you shift, the full load goes onto the converter and spikes the driveshaft causing the car to spin. This is VERY dangerous for small tire cars that have a front suspension limited to no travel. Without travel to help hook the tire, the car will lose control. You can help this by shifting out of low gear sooner, but the converter will ultimately have to be changed.
Heads Up or Class racers can gain a slight elapsed time advantage during the hot summer months by using the age proven method of packing the intake and carburetor in ice prior to an important run. Dual or high capacity “cool cans” filled with dry ice will add a similar, temporary gain. More recently, racers have found that by keeping a very minimum amount of fuel in the car, and adding cool or chilled fuel stored in the trailer or tow vehicle immediately prior to the run will add to the total elapsed time save. Replace and re-circulate the engine cooling system with ambient temperature water and you are ready for the next round, a few hundredths of a second quicker. Some racers have even drained the third member lube for and an extreme situation final round only advantage, but be warned – component damage or other consequences might result.
Yes. In order to get proper performance and winning results, do not forget your car’s braking system. OEM (Original equipment manufacturer) vehicle braking systems typically put up to 80% of the braking bias on the front wheels. This may need to be modified to provide more pressure to the rear tires. Not only does this provide for better holding power at the starting line for maximum performance and reaction time for “No-E” racers, but is also provides safer “brake light racing” in all forms of ET (elapsed time) racing. When rear tire width is often three to five times that of the front tires, front to rear braking bias must be adjusted to ensure safe, predictable high-speed braking.
When doing your burnout, slightly apply the break pedal to build some heat in the rear brakes. This allows the “foot-brake” racer maximum holding potential at the starting line, and warms the brakes to boost stopping power in all types of cars.
Three speed automatic transmission cars can sometimes realize an ET gain by short-shifting the first to second gear change. This is because there is significant rotational resistance involved in turning the reduction planetaries. By shifting sooner, the time period that this parasitic horsepower loss is imposed on the engine is minimized, freeing horsepower to the rear wheels. A similar, but less dramatic effect may also occur on the second to third up shift. When optimal gearing is present, the highest RPM level reached during the run will occur in high gear at the finish line where the least internal transmission drag is present.
First, spin tires slowly in water in order to get them wet while avoiding soaking the wheel wells. Second, pull to the front edge of the water using Low to High for Powerglide, Low to 2nd to high for Turbo 400, Ford C-4 and C-6, and 2nd to High only for Torqueflite and Turbo 350. Thirdly, when the tires are hot enough, release the line lock and power the car out of the water 5 to 10 feet and lift. Avoid hook up that will scuff tires. Finally – Stage immediately! Dry burnouts reduce traction and consistency. If you do not believe this, pay attention to your first dry leave behind the line. It will hook solid every time. Small amounts of water left on the tires will dry completely from the tire heat long before the green comes on.