Wayne Scraba is a diehard car guy and regular contributor to OnAllCylinders. Their offerings include rod ends, spacers, bushings, clamps, brackets, and mounting hardware for a number of items, from shocks, to brakes, to fuel cells. Anti-squat is a concept used to determine how much the rear of a chassis will squat under acceleration as a result of the rear geometry. sub frames in these cars move a lot when the car lifts at the front changing the pinion angle.. front sub frame is not tied gained by running the trailing arms upward to the front of the race car. With this system, the rear end stays located by virtue of the opposing angles of the upper and lower links. Made out of 1/2 thick steel to gain extra LR weight. These conditions call for a driving line that is more straight ahead. Adjust the length of the control arms as needed to achieve the desired pinion angle. the left rear tire to move forward. The asphalt racing surface provides a lot of traction, even on those flat "slick" tracks. The upper arms can be used to set the pinion angle by adjusting both arms in the same direction and by the same amount. clamp brackets. RAceman. At best, any trailing arm arrangement is a compromise between Maybe a up is a starting point. These stamped metric style control arms are great replacements for twisted or worn out control arms on your GM G-Body. birdcage moves forward during chassis roll instead of rearward as in In short Adjustable arms allow easy rear suspension . Suspension Division. "High left-rear loading does not increase traction," he said. Description : General Motors 64-67 "A-Body" Adjustable/Indestructible Rear Control Arm Upper Cross Member! Usually, the right-rear corner of the chassis moves more than the left-rear. KT-1B) makes removing a GM rear end from a GM Metric chassis much easier. keep in mind the effect that indexing has on suspension stiffness. 87 Chevy C10 upper control arms. Thanks so much! A drag race style anti-roll bar is a key ingredient to making your triangulated four-link work. right and 10 to 15 on the left provide good forward bite. 60 MAXIMUM aftermarket Ford 9 housing with new 3 OD tubes and 2.5 GN hub snouts. Undo the two bolts that hold the subframe support arm: the rear of the arm bolts to the front of the rear subframe, and the front of the arm bolts to the trailing arm bracket. right, the left rear tire can become loaded more quickly than the right 2022 Racelogic Street Stock Class Workbook, 1-7 Getting Your Cross Member Where You Want It, 1-14 Camaro Drag Link vs Metric Drag Link. The advantage of this system is that it keeps the rear end squared up and the thrust under acceleration straight ahead, if that is what is needed. This type of suspension has coil springs and upper and lower trailing arms (also called control arms). Brand new Stamped steel, C-channel arms are strong and sturdy Improve the handling of your '78-'88 GM Metric rear suspension by replacing twisted or worn out rear control arms 11" center to center Sold each IMCA Approved. KT-1A ). During chassis roll, trailing arm/s mounted upwards will cause the right It uses four links, as the name implies, that are not parallel to the centerline of the car. if u could move trailing arm mount on chassis with the uppers as close to the rearend housing as can get and the lowers 2.5 away from housing. Skip to main content. loading of the rear tires. This produces a motion ratio that causes the spring to move less than the chassis per degree of roll and/or inch of squat. 2- 175-B upper mounts. Or if you wish to keep your Edelbrock uppers, then just purchase a set of adjustable lowers (again, I prefer the double adjustable configurations theyre easy to tune in the car). Has a 1/4 hole on bottom to allow bolting to your weight jack bolt. West Coast Metric - Suspension Parts, Front & Rear. The rear will have Viking coil over shocks . $ The layout, lengths, and angles of the upper A-Arm work together with Lower Control Arm to encompass what engineers refer to as an Instant Center. REAR SUSPENSION: The following is a general list of rear ends and their dimensions to help narrow the search for a possible candidate to replace the torque tube rear end or just get a better set of gears for highway driving. Then this trailing arm bracket kit is a must have. ance with altitude u p to the equilibrium line. made to provide such handling, you must first understand a few basics The right-rear shock shows from 3 to 4 inches or more of travel, depending on the spring rates used. Designed for stock cars with a 7.5 max trailing arm length. I am setting up a GM A body 1972 Monte Carlo. Photo courtesy of BMR. Any angle up hill to the right rear will cause upward force on both tires and unload both tires. Consequently, a further reduction in loose roll steer results. Photo courtesy of BMR, BMR also offers lower trailing arms for Mustangs and GM mid-size cars. forward bite and roll steer. That way, the car will stay as fast and balanced as it can be throughout all of the changing conditions. It comes with a locking bolt to tighten the bushing. NOTE: Adjustable . positioned ahead of the axle and attached to And have fun at SIR! 2. When loose roll steer. Flying from Ho Chi Minh is hassle-free and convenient when you book with Cathay Pacific. The Metric four-link suspension design is a bit different than most other rear suspensions. on rough race tracks. 60 offset new reproduction stamping Ford 9 housing with new 3 tubes and GN hub type snouts. If we mount the left-side trailing arm lower than the right-side trailing arm, then as the rear end rotates under acceleration due to the pull bar extending, the left-rear wheel will move rearward more so than the right-rear wheel, causing rear steer to the left to a small degree. the 60 in the low 50s have 505hp 350 460fpt car weight 3400 what is your take on the pinion angle? These trailing arm brackets use common offset slugs (sold separately) to allow you to change the amount of lead or trail in the rear end. 1-15 How Important is it to Bump the Left Front? KT-1A). Tack weld the slugs to secure them to the trailing arm. I am getting ready to change my lowers out to some better ones that are adjustable. right side The bars can be mounted on one side of the car so that only that wheel moves to create the rear steer. if the left rear of your chassis hikes up during cornering, loose roll This has been confirmed by studying data from onboard computer systems during testing that show shock travel amounts in the turns. I have tried different set ups with some success am now at 4.5 down I want just for street use, nothing but just Soft Ride. Followed your advice and got a set of adjustable lowers. Currently my model has: * the lower control arm is angled up from ball joint to pivot at 4.1 degrees. Thats not necessarily bad. We've Thanks. He uses his knowledge as a racer to continue to innovate his chassis designs. A trick way to produce rear steer only under acceleration is by staggering the height of the two trailing arms in the 3-link system when using a pull bar, upper-third link. Under the wrong conditions, it can ruin your handling. That thought echoed Garrison's point of keeping the rear tires connected to the ground going in and through the middle, helping to provide traction off the corners. (on a clamp bracket) generally tightens corner handling. The Asphalt 3-Link - The 3-link rear suspension system has two trailing arms mounted near the rear tires, and one third link mounted atop the rear differential that controls rear end wrap-up. Rear steer in this system is caused by chassis movement, which can . Tack weld these washers to the outer flange of your bushing to create a retainer for the rubber. AA-621-A fits 3 axle tubes $14.95. My upper a arm is at a 10 degree angle pointing down towards the front. What is wrong ? without compromising forward bite. 4-link, wishbone, z-link or trailing arm type design are examples of geometry that affect anti-squat. I will post as I no longer race, the biggest thing is the angle of the upper and lower control arms in the rear, you need to understand roll center and instant center to be able to adjust it correctly. These trailing arms have fluted greasable, graphite/polyurethane bushings, which are superior to the stock rubber bushings. Adjustable lower bars are used to center the tires front to back in the wheel well and to make small wheelbase changes. OUT OF STOCK until appox. The trailing arms can be mounted parallel to the centerline of the car, or angled with the front mounts closer to centerline. movements of the In a high horsepower car, engine torque tends to rotate the car so the right rear tire has more bite. Jul 23, 2001. Additional washer added on end to extended life of bushing in severe conditions. birdcages typically move down much less than right side We do not necessarily need to know the exact amounts of rear steer our cars are subjected to, but we do need to have a solid understanding of what produces rear steer and what effect rear steer has on the handling in our cars. Masters added, "Any time we can press air against the sides of the car, we can help the car to turn." Raise the Rear Panhard Bar Up on both sides. When one wheel moves more than the other, we have a certain amount of rear steer. Loose roll steer causes the rear axle to steer towards the outside of suspension moves. JavaScript is disabled. PEM 9" Grand National Limited Floater Rear End Housing, RE-SSM-5800 is a 58" housing with a 0 pinion angle, stock mounts, and GM Metric caliper mounts. I have a blown 71 Chevelle. AA-384-B and AA-384-C), made from 3/16-thick steel, sit on the back of the lower trailing arm mounts. A well designed 4-link provides good forward bite and the proper The instant center is also rather high; the angles of the bars can raise it somewhere above the front wheel spindle. LR bracket is 6.75 from axle tube to center of bottom hole. A 1/2 inch height change from level can make significant handling changes. If the link angles become more upward on the left than on the about rear suspensions. all the best parts. Wayne thanks for the input Adaskaveg got his start working for track photographer Lloyd Burnham at Connecticuts Stafford Motor Speedway in 1970. Metric 4 Link Setup For Dirt steve smith autosports tech tips, the home of the jet mod and jet phantom the championship dirt track modified and stock chassis offering a full inventory of high performance racing parts racing safety equipment racing components and more lf 5 1 2 rf 5 3 4 lr 6 rr 6 1 4 our setup manual is the most in depth mod . 1 diameter x 11 long weight jack bolt. Another method used to reduce the loose roll steer of a 4-link Long bottom links (equal in length or no more than 1 For cars with spherical bearings (rod ends) or solid rear suspension bushings, most racers use a pinion angle between minus one to minus two degrees (minus is negative angle, or pointing down). As a result, the springs and This action will cause Also has a anti roll bar added to it. Your email address will not be published. The left-rear shock mostly seems to move between 1/2-inch in rebound and up to 1/2-inch in compression during the entire lap. A & A Manufacturing makes a similar trailing arm mounting kit for racers using Ford 9 rear ends in GM Metric chassis (part No. These arms fit 1978-87 GM G-body cars (Malibu, Monte Carlo, Regal, Cutlass, Grand Prix). attention to how the lower link adjustments change the paths traveled by two factors. All driving train actually repalced with Moog components.. We usually need to position the angle of the trailing arm so that the front mount is higher than the rear mount by roughly one third of the distance that the front mount will move down during cornering. Mounting both That gray-colored bar that goes up from the forward trailing arm mount is an aftermarket mounting brace that ties the upper and lower mounting points together. . I am looking for a bit more traction and less wheel spin, but primarly want better handling for road . There are a few similarities, but many differences in how we evaluate and use rear steer for each group. Check Tire temps, if LF is coolest (unbalanced setup): Decrease front springs, maybe even use reverse split (LF stiffer). When the panhard bar or J-bar is parallel with the rear axle center line, cornering force goes laterally and is the best vector to transmit this force. I use the H&R parts stuff anti roll bar $64.00. you will speed up your learning process by working with a model. birdcage now moves rearward (until the link reaches a level roll steer are overly affected and handling becomes inconsistent. amount of roll steer. The Truck-Arm System - The truck-arm system has been adapted from the design for a 1964 Chevy truck, and is used on many Late Model Stock cars, as well as the three premier divisions of NASCAR (Craftsman Trucks, Busch, and Winston Cup). The Z-link rear suspension, or swing arm as it is also known, is another system used on dirt cars. Upper link angles from 15 to 18 on the The upper arms is where many very in opinion. mounted 15 upwards to the front. the race car upon corner entry -especially when both coil-over units are With stock brackets on . Decrease the Angle of the Upper Trailing Arm. . Wehrs Body Bolt Panel Inserts. Location. A rear end steered to the left of centerline will cause the thrust angle to be left of centerline and make the car tighter on entry and tighter on exit under acceleration. The length of the bottom links are dependent on the roll steer and Get your shocks addressed (tested by someone with a shock dyno who knows what theyre doing) and then go back and work on the pinion angle, using the guidelines from the article. . The company offers a wide array of quality chassis components at reasonable prices. On a Late Model, this air pressure difference may help keep the car on the track by virtue of having the car go through the air at an angle, causing both a high pressure on the leading (right) side and a lower pressure on the trailing (left) side. minor relative to the overall handling improvement that is realized by You may be required to make chassis adjustments to This arrangement: * puts the instantaneous center 199 inches from center of car. All we had to do now was work on consistency. Trailing arms must also be running forward at the correct car builder design angle. Since we cannot lump them together, we will analyze them separately. The RR lower most will run . Adjust the pinion angle. 4. 1/2" on RF (5 degree angle of Upper A-Frame mounting bolts), 1/4" on LF, front higher than back, average bolt height the same as before. Outside Groove Note of Transparency: A&A Manufacturing paid for the production of this article. How Much is Too Much? If it had angle, as it moved up it would lengthen the wheelbase then pass level and start shortening the wheel base as it moves upward. A lot of guys take that to extremes.". Wehrs Metric Trailing Arm Bolt. The idea is to trace the paths actually Can I convert a combustion engine car to a hybrid car? can tighten overall corner handling by using The upper arms are angled to form the triangle that gives the suspension its name. Has a 1/4 hole on bottom to allow bolting to your weight jack bolt. This bolt on upper trailing arm mount is designed to allow use of a quick change into a stock GM metric chassis. (and tire) are forced towards the race track. Consequently, it may be necessary to increase rear spring rate Owner-operator at Race Products Inc. This bracket is also built heavy, weighs 7.5lbs (with slugs) to help increase LR rear end weight. One fix is to position the links so that the Click here to remove banner ads from this forum. (USRA/IMCA Stock Car Legal). Adjustable 73 - 77 . loose roll steer tendency caused by the steep angles of the upper links. When selecting springs for your 4-link, you should The first element to understand about rear steer is that it is caused by rear suspension movement. Decrease the Rear Weight Bias. The top links are angled from a top view with the front pivots wider than the rear pivots. However, a proven 4-link arrangement includes 15 1/2 bottom links, To ensure the pinion is in the correct location under power, it is typically set nose down in its at-rest (static) position. wenee9w Pit Crew. tire loadings. If its working correctly, a G Body will drag the back bumper on the track with those pieces, on small drag radials. the bottom of the To see if rear steer is an important tuning tool, we turned to some experts. 9-5 Upper A-Arm Mounting Points Metric. Notice, in illustration 2D, Tuning With Rear Steer birdcages during chassis roll. The GM Metric adjustable rear trailing arms will aid in adjusting pinion angle, centering the rear end and adjusting wheel base. Increase the Angle of the Upper Trailing Arm. Mike Kojima says: July 15, 2019 at 4:38 pm . right side link is from 3 to 5 higher than the left when the chassis The Metric 4-Link System - The metric 4-link is a widely used system that comes with some models of stock automobiles. Rear ends are straightened after jigging for truer alignment of axles to 3rd member. Let's expand on the other three systems. As a result, loose roll steer is reduced. AA-621-D is a clamp-on spring cup, fitting 3 tubing $24.95. When using trailing arm angles to help your setup it pays to truly understand the movements at each section of the corner as well as think about any drawbacks that rear steer or understeer might create. 88 metric lower trailing arm $65.00. 6. The 2-day class is broken down section by section. Lower the front LR trailing arm mount. Lower the Rear Panhard Bar on both sides. In racing, we have the maximum amount of traction from a pair of equally loaded tires on the same axle. of a 4 link suspension are the link lengths designed into the suspension (Steel). Hotchkis and Global West make similar control arms for Mustangs and GM A- and G-bodies. The rule about never steering the rear end to the right on an asphalt car does not apply on a dirt car. You should draw the paths to include Your DS length will dictate your lower link length. A triangulated four-link puts the instant center (I/C) locationthe imaginary point of where the rear suspension components intersect, and the point theyrotate around in a given (instant) positionway out front, often close to the engine. When the track goes slick, especially dry slick, rear steer is needed. during acceleration (due to the axle thrust effect). Designed for the Wissota street stocks, these trailing arm brackets have the lowest mounting hole position possible. Since then, hes been a columnist, writer, and photographer, in racing and in mainstream media, for several outlets, including the Journal Inquirer, Boston Herald, Stock Car Racing, and Speedway Illustrated. They are angled to fit GM Metric chassis and have four holes for racers to adjust their trailing arm position. Insert the bolts to the ends of the control arm Lower the jack from the transmission Tap the bolt into the control arm Raise the rear suspension to simulate ride height Torque the bolt to 95 foot-pounds Torque the bolt near the rear axle to 103 foot . Simply replace the slug with different combination of offset slugs. best for tight, flat race tracks or on any track where the chassis tends Dirt Late Model cars can be designed with a considerable degree of adjustment for rear steer. With this design, lateral movement of the rear end causes rear steer. The following examples and illustrations should help you to understand So, teams need to take this rate difference into account. New info from @Fabman on RLCA angle: 3 to 5 degrees downward slope . to -mile numbers by multiplying by 1.54. A/C Condenser APDI 7013457 fits 2006 Mitsubishi Eclipse, Mevotech TTX Front Lower Suspension Ball Joint for 1998-2018 Subaru Forester vc. You are using an out of date browser. This caliper mount brackets is built to fit the small GM metric calipers. If the front is diving under braking then add anti-dive to front suspension. suspension is to shorten the bottom links. We highly recommend that you build a full-scale working model of your It may not display this or other websites correctly. Improve the cornering capabilities of your race car with these new rear control arms and bushings from Speedway Motors. The upper arms on a triangulated four-link are used to center the rear axle housing from side to side; you shift the rear axle housing left or right, depending upon which bar you adjust. A downside to using the truck arms is not related to steering characteristics, but due to a narrow spring base when the springs are mounted directly on top of the truck arms, creating a narrow spring base in the rear. MAXIMUM Performance right side climbing panhard mount for Ford 9 rear ends. CTS Upper Metric Trailing Arm Mounts for Ford 9 inch housings. My trailing arms are stock triangulation. In Stock . The content was subject to approval of A & A Manufacturing. It comes with a locking bolt to tighten the bushing. suspension). Conversely anti-dive is used to describe how much a chassis nose dives under braking. However, indexing can cause the rear suspension to be too harsh This kit includes two Pull bushings, two steel spools, a rectangular mount tube and side gusset bracket. At the nose, Id do the same (spherical bearings or Delrin bushings). sensitive to adjustments. Ben from AFCO Racing is an expert in multiple aspects of race cars including cooling and set up. * puts the roll center 3.3 inches off the ground. Hes authored five how-to books and written over 4,500 tech articles that have appeared in sixty different high performance automotive, motorcycle and aviation magazines worldwide. Rayburn of Rayburn Race Cars, a driver as well as a car builder, echoed much of what the other buiders had to say. This will make it easier to line up the new control arms when they are installed. Perfect for the guys that already have or Extreme or Xtrmer Drop brackets. change of 5 can make a noticeable change to handling. Kit contains: (2) Rear upper control . Some manufacturers have added multiple mounting points on the front and rear chassis mounts. Mounts J-Bar to 9 third-member 4 3/8 offset from pinion. This induces less rear steer when the car squats on exit. In turn, that bite tends to move the car toward the left. As the suspension in a car wraps up, the pinion is driven upward. shortening the lower links, is a reduction in loose roll steer. It comes with all the pieces necessary for you to start saving time and energy, and it wont break the piggy bank. The side bite trade off is a big one. Here is how each system functions and how they can be adjusted for the "degree" of rear steer. You can lengthen or shorten the bar by loosening the jam nuts on either end and turning the adjuster. Because there is very little slip of the tires on asphalt, the range of useable rear steer is very small. This will give you a lower rear roll center and aide side bite. Most of the Z-link systems utilize a spring mounting system that attaches the coilover spring to the front link. The live class took place January 22-23, 2022. Do I need to change my angles on my trailing arms to get forward bite? front of the The popularity of the 4-link suspension is due primarily to its Insane video on the induced rear roll over steer. Just as bad, some of the top-mount arms (ones that physically raise the upper trailing arm location on the rear end housing) have a tendency to hammer the trunk floor when you get on the throttle. The front locating points must be in the stock locations. Heres a look at an adjustable upper trailing arm fitted to a GM G-body. Assembly includes: 2.5 MAXIMUM GN hubs, hub bearings, seals, brake rotor, drive flange, axles and all hardware necessary. Rear steer in a circle track race car is a condition caused by suspension movement. everything is a compromise. The entry is more important to design for than the exit as far as rear steer is concerned." 1-1/2 Tube Diameter Clamp For Limit Chains on Chassis Side, 1-3/4 Tube Diameter Clamp For Limit Chains on Chassis Side. 266. Lower the Rear Panhard Bar on both sides (frame and rear-end attachment).