Bars like this are typically welded into the chassis and tied to the housing by adjustable links. The key to correctly Suspension Parts, Front & Rear parts . Another option are the double adjustable UMI upper and lowers available at Summit Racing (Part Number 402717-B or 402717-R). This is correct. Most of the Z-link systems utilize a spring mounting system that attaches the coilover spring to the front link. In dirt racing, it may be advantageous to incorporate a large amount of rear steer under certain conditions. A & A Manufacturing makes a similar trailing arm mounting kit for racers using Ford 9 rear ends in GM Metric chassis (part No. For example, in illustration 2A, both the top and the bottom links roll steer. you will speed up your learning process by working with a model. To help understand the Instant Center you can visualize a triangle (Fig. Welcome Guest. $64.00. 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. Location. coil-over units directly to the axle housing. Just opposite of whats pictured here. Richards added that "if the driver has to countersteer the car a lot, you need more rear steer.". (Sold Individually). How to Determine Over-Amperage on Pulley Size Change. After subframe support arm is out of the way, unscrew the . 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. But as youll see in the photos, adjustable trailing arms are the firstand bestmethod of setting up a triangulated four-link for drag racing. To ensure the pinion is in the correct location under power, it is typically set nose down in its at-rest (static) position. I hear of 305 cid stockers running in the high 1.40s far less hp I have adjustable qa1 shocks This produces quite a bit of rear steer to the right, moving the rear of the car to the right, just like when we used to throw the car sideways. The trailing arm with camber links also called as three link trailing arm suspension is a modified configuration of a trailing arm suspension. LZ-13-B) from 3/16-thick steel. ance with altitude u p to the equilibrium line. Now on to getting everything adjusted out and working. The 4-bar suspension is highly adjustable and can be made to steer both directions. BMS Racecars - Winning's not just a goal it's a tradition! Heres a better look at a trailing arm mounting brace. Now with Ten properly positioned holes . of a 4 link suspension are the link lengths designed into the suspension We hope the information in this article, combined with your 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. Housings have fill and drain plug installed. The front of the car felt the actual 400-pound rate while the rears "felt" like 200 pound springs. loose roll steer by making the lower links shorter than the upper links 60 offset new reproduction stamping Ford 9 housing with new 3 tubes and GN hub type snouts. chassis up during acceleration which can reduce the effectiveness of the On asphalt, do not make large changes to components that influence rear steer. As we stated earlier, the 4-link is a fairly complicated rear excessive if the rear of the chassis lifts a lot during acceleration. 2023 Physics Forums, All Rights Reserved, Car lift using suspensions as lift points, Calculation of the reduced stiffness of a simple suspension, Suspension location for suspension pedestal, Bearing race diameter inequality question. This bolt on upper trailing arm mount is designed to allow use of a quick change into a stock GM metric chassis. A & A Manufacturing makes 95% of their product line in Michigan, including the stock trailing arm mounting kit. * upper control arm angled down from ball joint to pivot at 1.4 degrees. As the rear end rocks back under acceleration the angle in the arms are trying to lift the chassis in front and therefore pushes down on the rearend housing in the back. Bushings in Upper Mounts Im converting a Pro-Challenge car for road racing, ad Id like to get rid of the Panhard bar, and go to triangulated upper links. loose roll steer. the right side AA-621-B fits 2-5/8 ones $14.95. Rear steer amounts-due to the Panhard bar angle-are regulated by the angle. UMI part numbers are 4023CM-B or 4023CM-R. clamp brackets. Keep in mind that any change to the The RR lower most will run level. Conversely anti-dive is used to describe how much a chassis nose dives under braking. (more on this later). Other teams may just stick with a fixed location for the mounts in the rear end and adjust handling with other means. The upper arms is where many very in opinion. In short Again the height of the mounts are critical as to the resultant force transmitted. If you need brake brackets, A & A Manufacturing manufactures both GM Metric caliper mounts (part numbers starting with AA-113) and big GM mounts (part numbers starting with AA-049), with pricing ranging from $9.82 to $15.84 per bracket. You can evaluate the roll steer characteristics of different set-ups There are times when we definitely want the rear to steer to the right. Its on a car that Im helping with. Richards added that today, the Z-link or swing-arm suspension can have nearly as much rear steer as the 4-link, without the excessive loading of the left-rear tire. Mounting the left coil-over unit ahead of the axle 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. The setup is balanced when the LF and LR tire temps are similar. That way, the car will stay as fast and balanced as it can be throughout all of the changing conditions. Posts: 5 Metric Rear suspension tricks Dec 31, 2012 20:24:48 GMT -6 . 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. Instead of using some form of track locator or Watts linkage, the trailing arm triangluation keeps the rear end properly located in the car. KT-1B) makes removing a GM rear end from a GM Metric chassis much easier. . 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). Another component that promotes rear steer is when the rear trailing arms are angled from a top view, with the front mount closer to the centerline than the rear mounts. Depending on the angles of the trailing arms or bars, each rear wheel can be made to move to the front or rear. The trailing arms can be mounted parallel to the centerline of the car, or angled with the front mounts closer to centerline. Spring Motion Ratio - Trailing Arm Brackets - Bushings in Upper Mounts - Brake Caliper Mounts (GM Metric) . Fox80. Order your Trailing Arm 2 Piece Set - today at 1AAuto.com. Dave here in Saskatoon been racing a g body for many years now and struggle to get AA-621-D is a clamp-on spring cup, fitting 3 tubing $24.95. One fix is to position the links so that the Decrease the Rear Weight Bias. wenee9w Pit Crew. In turn, that bite tends to move the car toward the left. If you look at a modern dirt Late Model, the sides are made up of big, flat panels similar to the sides of a Sprint Car wing. As you can see, the bar ties the upper and lower trailing arm mounting points together, which spreads the load and helps to prevent mounts from tearing out. The idea is to trace the paths actually This will add Roll Steer as the chassis rolls over in the turn and the LR arm scribes an arc forward and shortens the left side wheel base. Adjustable 73 - 77 . REAR - On each side of the vehicle, measure the distance (2) from the center of the outboard trailing arm-to-body mounting bolt (1) to the floor or alignment rack/lift runway surface. Stock trailing arm kit, used for mounting Ford 9 in GM metric car. tuning a 4-link, it is important to understand the relationship between 2.50 from axle tube to center of hole. birdcages move up during chassis roll, the overall effect, when am out of adjustment on the uppers so will be installing a set of adjustable lowers $ The left-rear suspension is designed so that when that corner raises up, the arms are angled, pulling the left-rear wheel forward towards the driver. You can Watch, Rewind, and Watch Again. Sep 1, 2009. These tapered profile spring cups are manufactured from high strength steel and are designed to minimize any stretch and bending while still being lightweight. 4.0 drop trailing arm brackets slotted to accept offset slugs. The rear will have Viking coil over shocks . Adjust the pinion angle. Make small adjustments if you feel a need. The Metric four-link suspension design is a bit different than most other rear suspensions. path traveled by any trailing arm will affect roll steer. 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. You can see how this adjustment works in illustration 2B. Has gone 1.29 60 ft on spray, has 28 10.5 et street tires on it also. Not sure if there are any big "Tricks". Part No. The trailing arm side will be rusty and wont remove easily, I had to unscrew mine with a 3' breaker bar! (on a clamp bracket) generally tightens corner handling. In the past, drivers would set up the car for exit off the corners, throwing the car sideways by breaking the rear tires loose. We should learn to read the conditions of the dirt tracks and tune the amount of rear steer-less for tacky and wet conditions, with more rear steer as the track gets slicker. We never need our suspension to steer the rear end to the right of centerline on asphalt. That can work for a mild street or bracket car, but will make a high-horsepower car react violently at launch. Tack weld the slugs to secure them to the trailing arm. In more recent years, teams have been setting up the car so that the left side raises up quite a bit. On cars with triangulated upper control arms, you cant set preload with adjustable arms. Learn how your comment data is processed. 4AN To for 8mm X 1.0 Metric Straight Adapter Vibrant. the other illustrations. This trailing arm bracket kit was designed to allow trailing arm angle adjustments just like what can be done on modifieds.. clamp brackets to mount the left coil-over unit ahead of the axle Decrease the Pre-Load on the Stabilizer Bar. Among Adaskavegs many awards are the 1992 Eastern Motorsport Press Association (EMPA) Ace Lane Photographer of the Year and the 2019 National Motorsports Press Association (NMPA) George Cunningham Writer of the Year. LATE MODEL SUSPENSION FRONT-REAR; LATE MODEL DRIVELINE-WHEELS; . This bracket is also built heavy, weigh 7.5lbs (with slugs) to help increase LR rear end weight. Housings havefill and drain plug installed. You are using an out of date browser. Trailing Arm Brackets try to drive underneath the chassis as the rear axle pushes the race car In the last pass of the night, the Chevelle delivered a 1.629-second 60-foot time on the way to a 7.014 / 99.71 mph pass. Decrease Upper Control Arm Angle on the Rearend. the left rear tire and wedge is reduced (40 lbs to 80 lbs is typical!). clamp brackets and ahead of the axle can improve forward bite on unloading of the rear tires during deceleration This unloading can upset Generally, bottom link angles from 0 to 5 downhill (to the front) With adjustable trailing arms (rather than the factory originals), you can adjust the pinion angle by simply changing the length of the upper trailing arm. shocks are compressed from both ends at once and the suspension becomes without compromising forward bite. with the very soft chassis meaning floppy front subframe is 4.5 enough? Metric Chassis Complete A-Arm Assembly $ 99.95; Camaro Chassis A-Arm Shaft Assembly $ 99.95; JOES 24" Pit Steering . Mounts J-Bar to QC rear end 4 3/8 offset from pinion. The system works well enough on the street, but not so well when it comes to hooking up at the drag strip, especially with big horsepower. If the upper links are shorter than 17", the lower 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. They constantly introduce new products to their lineup. Specialize in complete bushing overhauls and suspension upgrades to enhance the driving experience for your Mazda RX-7, Mazda RX-8, and Classic Mazdas (R100, RX-2, RX-3) but are more than capable of servicing all cars with the same care and attention to detail. correctly. 4. Adjustable trailing arms will allow you to set the static pinion angle. Trailing arms must also be running forward at the correct car builder design angle. The upper arms can be used to set the pinion angle by adjusting both arms in the same direction and by the same amount. AA-175-D. Adjustable lower bars are used to center the tires front to back in the wheel well and to make small wheelbase changes. Now you have to compensate with spring change. Part No. The two most critical factors to the performance It may not display this or other websites correctly. One of the reasons a car will test fast in practice, qualifying, and maybe the heat races, but then be out to lunch when the track changes come feature time, is a result of improper rear steer. If excessive, loose roll steer can cause a loose Shock brackets (part No. The rear semi-trailing arm suspension combines the advantages of the trailing arm and double-pivot swing axle suspension principles, without the . This condition may but there are ways to get that back. Followed your advice and got a set of adjustable lowers. JavaScript is disabled. Wehrs Modular Non-Adjustable T-Bar. This type of suspension has coil springs and upper and lower trailing arms (also called control arms). Then, a 1" weld on the bottom inside of the left side." forward on the left side during chassis roll. clamp brackets. initial forward bite. Then this NEW trailing arm bracket kit is a must have. and parallel to each other). the bottom of the All we had to do now was work on consistency. Wehrs Bent Suspension Tubes 5/8"-18 Thread. This is done to add more angle to the lower trailing arms, which adds roll steer to the rear, as the body rolls. Used on millions of cars - BMW, Mercedes, Ford and even Rolls Royce - semi-trailing arm rear suspension had some huge advantages. On most flat- to medium-banked tracks, the left-rear moves very little. The significance of this, for the purpose of this article, is that the chassis travel in a Z-link is enhanced compared to the 4-link suspension when using the same installed spring rate, and this causes quite a bit of chassis travel and related rear steer. minor relative to the overall handling improvement that is realized by Up To 50% Off Prices EveryDay! It comes with a locking bolt to tighten the bushing. (Try to bounce the rear of a car with a 4-link rear On the left side, the bottom The company manufactures the kits lower trailing arm mounts (part No. AA-175-B) are constructed from stout 5/8-thick steel. Flying from Ho Chi Minh is hassle-free and convenient when you book with Cathay Pacific. clamp brackets during acceleration will be accompanied by an Owner-operator at Race Products Inc. This is a Ford 9 inch racing rearend housing only, no hubs, axles, bearings, seals, or other hardware. keep in mind the effect that indexing has on suspension stiffness. These conditions call for a driving line that is more straight ahead. Wayne Scraba is a diehard car guy and regular contributor to OnAllCylinders. CTS Upper Metric Trailing Arm Mounts for Ford 9 inch housings. birdcage now moves rearward (until the link reaches a level In Stock . Indexing can improve driveability by keeping the race car flat in the On extremely slick race tracks, you Improve the cornering capabilities of your race car with these new rear control arms and bushings from Speedway Motors. We can relate 1/8-mile e.t. I want just for street use, nothing but just Soft Ride. Youll find that an instant location similar to stock is actually close to optimum, provided you dont jack the body way up in the air. A link length change of 1" or a link angle birdcages caused by the upper links. Decrease the Angle of the Upper Trailing Arm. However, indexing can cause the rear suspension to be too harsh But it also had downsides . As a result, loose roll steer is reduced. Large 1 NPT fill plug installed for easy filling or connecting to fill tank. Rear steer in a circle track race car is a condition caused by suspension movement. Realize that you can increase forward bite on any type of rear Condition: New. Wayne The bottom trailing arms are adjusted at the back end of the bar near the rear axle housing. Thanks . I want just for street use, nothing but just Soft Ride, floating kind of .. What is wrong ? At best, any trailing arm arrangement is a compromise between One trick I always used was to drill through the nut and bolt on the arms and use a cotter pin to lock the nut. Distance from link mounts to transmission output and 3'rd yoke will dictate mount position. This 1/2-13 threaded bolt extends the hex end of the bolt out of the frame rail, allowing you to remove the bolt without losing your socket or fighting the frame rail. Obviously, if both of the wheels did not move, or moved in the same direction by the same amount, we would have zero rear steer. article to determine the correct link lengths for your application. These arms also use rod ends on each end to prevent binding when under load. Justin is the owner of High Roller Race Cars. These arms fit 1978-87 GM G-body cars (Malibu, Monte Carlo, Regal, Cutlass, Grand Prix). In this case, that equates to a 10.80. It has been a practice for teams to align the rear end-and/or have it steer slightly to the right-to fix a tight mid-corner condition, but this goes into the category of crutches, and should not be necessary if the car is set up properly otherwise. In simple terms, it keeps the body from roll rotating on the launch. Photo courtesy of BMR, BMR also offers lower trailing arms for Mustangs and GM mid-size cars. KT-1A ). The bushed end has a Teflon-lined QA1 stainless steel spherical bearing (rod end) with a stainless steel spacer. 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. On the left, we have reduced the forward movement of mounted 15 upwards to the front. I am going to raise the car next to achieve ideal front lower control arm angle (still to low for that) then corner balance and tweak from there. (USRA/IMCA Stock Car Legal). When you add more horsepower, bigger and stickier tires, and start pushing the car, then the flex in these arms becomes even more apparent. it feels as a plank over nude bearings on the road .. Their offerings include rod ends, spacers, bushings, clamps, brackets, and mounting hardware for a number of items, from shocks, to brakes, to fuel cells. I'm not sure of the Task Force width . traction characteristics desired by the chassis tuner. Wayne acceleration causes the rear axle & chassis to separate. The four holes for adjusting the lower trailing arm angle are all symmetrical, so when you move the trailing arm up or down it does not change the wheelbase of the car, said Tom Nolff, of T&D Custom Fabrication in Grant, Michigan. 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. We stated earlier that trailing arms mounted upwards to the front of Made out of 1/2 thick steel to gain extra LR weight. $15.75. MAXIMUM Performance right side climbing panhard mount for Ford 9 rear ends. We can reduce loose roll steer further by lowering the These trailing arms will improve handling of the rear suspension by replacing either twisted or worn out OE control arms. 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. "High left-rear loading does not increase traction," he said. about rear suspensions. Built with corrected pinion angle and our proven "Pull" Bushings. suspension bump (compression) movement. Wehrs Modified Valance Support. Buy Traxxas 9530: Suspension Arm, Front (Right), Black From RCMA For The Best Deals In Australia, We Also Have Same Day Shipping On All Orders Placed Before 3PM Today! Below you'll find a selection of our flight destinations to spark your interest. handling condition that negates the benefits of the forward bite gained Check Tire temps, if LF is coolest (unbalanced setup): Decrease front springs, maybe even use reverse split (LF stiffer). You should use the information in this Also has a anti roll bar added to it. With this design, lateral movement of the rear end causes rear steer. Finally, Im not exactly sure what you mean by a floppy front subframe. Trailing arms mounted in this manner cause the rear tires to Short links( from 3 to 4 shorter than the upper links) generally work SourceA & A ManufacturingSpring Lake, Michigan800-473-1730aa-mfg.com. There can be a small amount of rear steer as the chassis rolls and squats, but it is both minimal and mostly fixed as far as adjustability. cause a gas pedal push. 122. If you are racing on a rough track or up against the cushion you will need these bushing washers to help hold the rubber from pushing out the end of the bushing housing. 2.5 drop trailing arm brackets slotted to accept offset slugs. starting point for both links is 15 upwards (to the front). race car. 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. * puts the roll center 3.3 inches off the ground. 88 metric lower trailing arm $65.00. It uses four links, as the name implies, that are not parallel to the centerline of the car. suspension moves (unless both upper and lower links are equal in length These new Currie 31-spline axles feature press in studs in a 54 3/4 wheel bolt pattern, , thick heavy duty bearing retainer plates, and tapered wheel bearings pressed on. Most will run the LR angled down in the back. the indexing and the link angle changes during roll or bump. Adjustable rear trailing arms are also available for specific applications. suspension. Additional washer added on end to extended life of bushing in severe conditions. All driving train actually repalced with Moog components.. Asphalt stock cars have four predominant rear suspension systems and all of them produce some amount of rear steer. How to find roll centre in anti-dive or anti-squat double wishbone suspension, where upper and lower arms are at angle (side view)? If you run the frame side of the J-bar is higher . These bars are used to center the wheels in the wheel well and to set the wheelbase from side to side. The instant center is also rather high; the angles of the bars can raise it somewhere above the front wheel spindle. A good At the nose, Id do the same (spherical bearings or Delrin bushings). (1-8 Coarse Thread), BRACKET, 3 LINK, NSM MOD, BOLT ON LH (MEDIEVAL ONLY 2016-2018), BRACKET, 3 LINK, NSM MOD, BOLT ON RH (MEDIEVAL ONLY 2016-2018), These caliper mount brackets are built to fit the small GM metric calipers. Adjustable arms allow easy rear suspension . 2. We've Characteristics of the metric 4-link, one of those four, are the same as discussed under the heading related to asphalt cars. Looking for that edge over everyone else. The lower links are angled from a top view with the front pivots narrower than the rear pivots. Wehrs Bent Suspension Bar Angle Finder. links have to be extremely short to minimize loose roll steer. Changes in the height of the front of the trailing arm as small as a 1/4-inch can be felt by the driver. 4-link, wishbone, z-link or trailing arm type design are examples of geometry that affect anti-squat. Great info! My lower trailing arm is level. (Sold Individually). Wehrs Body Bolt Panel Inserts. Decrease LR Shock rebound and/or increase RF Shock compresion. This is accomplished by causing the right-rear wheel to move back and the left-rear wheel to move forward as the car rolls. This induces less rear steer when the car squats on exit. Oct 12, 2013 #2. The 4-link is a relatively complex rear suspension that is very and rearward (R.S.) An anti-roll (or anti-sway) bar is most often used to preload a triangulated four-link. As a result, we reduced loose I am getting ready to change my lowers out to some better ones that are adjustable. 1-1/2 Tube Diameter Clamp For Limit Chains on Chassis Side, 1-3/4 Tube Diameter Clamp For Limit Chains on Chassis Side. For more than 50 years, A & A Manufacturing has worked closely with racers and chassis fabricators. A level panhard bar ( same mounting height on both sides) means force is vectored laterally to the tires. 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. There are a few similarities, but many differences in how we evaluate and use rear steer for each group. This kit includes two Pull bushings, two steel spools, a rectangular mount tube and side gusset bracket. This produces a motion ratio that causes the spring to move less than the chassis per degree of roll and/or inch of squat. Long bottom links (equal in length or no more than 1 I do have a few questions though: Are you running the car with an Anti Roll Bar or at the least, with a sway bar on the back? So, teams need to take this rate difference into account. The upper trailing arms are pretty much in the stock location. One of the things we have done, is to raise the rear ride height. Lower the front LR trailing arm mount. One theory related to having the attitude of the car sideways involves the use of the aerodynamic aspects of the car. For example, you want the top link to be perpendicular to the rear end housing and parallel to the car. Has a 1/4 hole on bottom to allow bolting to your weight jack bolt. We can reduce loose roll steer by lowering the bottom links at the This will make it easier to line up the new control arms when they are installed. You can play with all of these a little to work on plunge/roll steer. (during acceleration) is quickened and forward bite is enhanced. Consequently, it may be necessary to increase rear spring rate you to better understand the 4-link suspension. The Impala spindles are the " hot set up " on a metric chassis. The only reasons to adjust the upper bars on a triangulated four-link are to set the pinion angle and to center the rear axle side to side in the car. Part No. If the Panhard bar is mounted on the right side of the chassis and level to the ground, the rear end will be pulled to the right, and will steer to the left when the chassis moves during cornering. Adaskaveg got his start working for track photographer Lloyd Burnham at Connecticuts Stafford Motor Speedway in 1970. No more than 10-15 pound difference, excess split makes car tight. However, a proven 4-link arrangement includes 15 1/2 bottom links, Suspension Type Camber Angle; FWD: Multilink Trailing Arm Twist Beam: 1.0 1.0 1.0 RWD: Multilink Trailing Arm Swing Arm: 1.0 1.0 1.3 AWD: Multilink Double Wishbone Trailing Arm: 1.0 1.0 1.0 4WD: Multilink Double Wishbone Trailing Arm: 0.5 0.5 0.5 Some forward bite may be lost when This will add Roll Steer as the chassis rolls over in the turn and the LR arm scribes an arc forward and shortens the left side wheel base. of the right and 10 to 15 on the left provide good forward bite. #2. pat the angle of the trailing arm wont really effect anything that much. US $239.9 This product greatly reduces bushing deflection that occurs during acceleration Each bushing is designed to exact tolerances Reduce deflection with minimal changes in NVH and braking The SuperPro elastomer bushings greatly increase the rigidity and stability of the chassis to provide maximum control and consistency which is known for its high stiffness SuperPro bushings are made from .