Also has a anti roll bar added to it. That helps equalize traction to the rear tires. Then, a 1" weld on the bottom inside of the left side." 1 diameter x 11 long weight jack bolt. starting point for both links is 15 upwards (to the front). Use this kit to build your own custom rear end. Balance the Front and Rear stiffness. On extremely dry, slick conditions, use lots of rear steer to the right. 87 Chevy C10 upper control arms. Rayburn builds the swing-arm type of rear suspension. Tubular arms are constructed of 1 1/4" diameter .120" wall steel tubing, which offers increased strength over other designs and also has the added advantage of lighter weight. 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. . It seems not being an Irak/bu . Long bottom links (equal in length or no more than 1 Simply replace the LR bracket and have increase drive and adjustability. JavaScript is disabled. this important function of the lower links. rear tire to move rearward (until the arm/s reach a level position) and Keep in mind that trailing arm angles can become excessive if the rear of the chassis lifts a lot during acceleration. Matt, The upper arms are angled to form the triangle that gives the suspension its name. Wayne Scraba is a diehard car guy and regular contributor to OnAllCylinders. KT-1B) sells for $96.00. shorter than the upper links) work best for fast tracks or on any track Posts: 5 Metric Rear suspension tricks Dec 31, 2012 20:24:48 GMT -6 . Richards added that "if the driver has to countersteer the car a lot, you need more rear steer.". The front may be too stiff compared to the rear. 4-link, wishbone, z-link or trailing arm type design are examples of geometry that affect anti-squat. stop and go or slick race tracks. I hear of 305 cid stockers running in the high 1.40s far less hp I have adjustable qa1 shocks This trailing arm bracket kit was designed to allow trailing arm angle adjustments just like what can be done on modifieds.. Oct 12, 2013 #2. birdcages during chassis roll. This will make it easier to line up the new control arms when they are installed. path traveled by any trailing arm will affect roll steer. Part No. KT-1B) makes removing a GM rear end from a GM Metric chassis much easier. The upper trailing arm mounts (part No. This Spring Cup is extended to hold the spring while the chassis hikes for Northern Sport Mods and Limited Mods. We could reduce loose roll steer even further by combining the long (and tire) are forced towards the race track. Increase the Split in the Panhard Bar Heights. Rayburn of Rayburn Race Cars, a driver as well as a car builder, echoed much of what the other buiders had to say. Specifically designed to increase LR drive off the corner and corner entry adjustability with multiple hole adjustments on the RR. Because there is very little slip of the tires on asphalt, the range of useable rear steer is very small. So, teams need to take this rate difference into account. Typically, indexing causes the coil-over mounts, if located on the 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 front of the car felt the actual 400-pound rate while the rears "felt" like 200 pound springs. When As a result, loose roll steer is reduced. July 1st. Our services include: Bushing overhauls, suspension repairs . birdcage forward during chassis roll more than the longer links in The GM Metric adjustable rear trailing arms will aid in adjusting pinion angle, centering the rear end and adjusting wheel base. 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. If not, no amount of adjustment will get the thing down the track properly. Unbolt and remove one upper rear control arm using a " wrench. You can play with all of these a little to work on plunge/roll steer. This condition will cause loose handling-especially ability to let the race car turn freely in the middle of the corner This arrangement: * puts the instantaneous center 199 inches from center of car. A lot of guys take that to extremes.". . Raise the front LR trailing arm mount. 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. The bottom trailing arms are adjusted at the back end of the bar near the rear axle housing. AA-175-C). BMS Racecars - Winning's not just a goal it's a tradition! SportMod jigged. You should pay close on rough race tracks. Bushings in Upper Mounts Spring Perchs & Brake Caliper Brackets are now Bolt-On Accessories (not included in Rear End Housing Price). 3. In Stock . reducing loose roll steer. the left rear tire and wedge is reduced (40 lbs to 80 lbs is typical!). have qa1 adjustable coil over shocks without the coil have a tube welded across the frame at the back to mount the shocks like a ladder bar Large 1 NPT fill plug installed for easy filling or connecting to fill tank. Knowing these basics, we need to look at each type of racing to see how rear steer affects each type of car and how we might improve our performance using rear steer. tuning a 4-link, it is important to understand the relationship between I am dropping my ride height 2. if the left rear of your chassis hikes up during cornering, loose roll LZ-13-B) from 3/16-thick steel. If you lengthen the same bar, more load is placed on the left rear tire. 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). 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 from axle tube to center of hole. - Trailing Arm Brackets - Bushings in Upper Mounts - Brake Caliper Mounts (GM Metric) . The bars can be mounted on one side of the car so that only that wheel moves to create the rear steer. NOTE: Adjustable . Decrease the Split on the Rear Panhard Bar Heights. With this design, lateral movement of the rear end causes rear steer. 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. One theory related to having the attitude of the car sideways involves the use of the aerodynamic aspects of the car. Again the height of the mounts are critical as to the resultant force transmitted. Lower the front LR trailing arm mount. If you run the frame side of the J-bar is higher . can tighten overall corner handling by using Dirt Rear Steer My car had 7Deg of angle it. 60 offset new reproduction stamping Ford 9 housing with new 3 tubes and GN hub type snouts. the right side Rear steer in this system is caused by chassis movement, which can . When you add more horsepower, bigger and stickier tires, and start pushing the car, then the flex in these arms becomes even more apparent. (Try to bounce the rear of a car with a 4-link rear the other illustrations. positioned ahead of the axle and attached to Mounts J-Bar to QC rear end 4 3/8 offset from pinion. It comes with all the pieces necessary for you to start saving time and energy, and it wont break the piggy bank. There are four types of rear suspensions used in most dirt cars that are significant to study regarding rear steer. In simple terms, it keeps the body from roll rotating on the launch. Under the wrong conditions, it can ruin your handling. We hope the information in this article, combined with your 650 whp. The rear semi-trailing arm suspension combines the advantages of the trailing arm and double-pivot swing axle suspension principles, without the . Jul 23, 2001. I am setting up a GM A body 1972 Monte Carlo. Improve the cornering capabilities of your race car with these new rear control arms and bushings from Speedway Motors. right amount of loose roll steer can help a race car to turn the corner loose roll steer tendency caused by the steep angles of the upper links. 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? Show more About this course $299.00; 160 lessons . Lower the Rear Panhard Bar on both sides (frame and rear-end attachment). Another method used to reduce the loose roll steer of a 4-link made to provide such handling, you must first understand a few basics 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. 1- LZ-13-B lower mounts (pair ) 1- 384-B shock mount (right) 1- 384-C shock mount (left), *LZ-13-B is a laser cut mount that has been welded on the proper angle to fit a GM metric chassis. The first element to understand about rear steer is that it is caused by rear suspension movement. Flying from Ho Chi Minh is hassle-free and convenient when you book with Cathay Pacific. Cars with 15-inch wheels should have a measurement of 205mm (8.07") in front. Reply. suspension). There are limits to how far we go in steering the car this way. Now available value added Metric Rear Control Arm . 88 metric lower trailing arm $65.00. These are BMR upper trailing arms for 1979-2001 Mustangs. Hes owned his own speed shop, built race cars, street rods, and custom motorcycles, and restored muscle cars. The company manufactures the kits lower trailing arm mounts (part No. forward (See illustration 1). Ground clearance at bump and uptravel at ride height will dictate link angle. Required fields are marked *. Tuning With Rear Steer (during acceleration) is quickened and forward bite is enhanced. The following examples and illustrations should help you to understand I had 17 Deg of angle in my car, down in front and up in back. The 4-link is a relatively complex rear suspension that is very . Adjustable arms allow easy rear suspension . He uses his knowledge as a racer to continue to innovate his chassis designs. There are three items to address: shocks, anti-roll bar, and adjustable trailing arms. Let's expand on the other three systems. Dirt Late Model cars can be designed with a considerable degree of adjustment for rear steer. When one wheel moves more than the other, we have a certain amount of rear steer. The length of the upper links should be at least 17" . These arms also use rod ends on each end to prevent binding when under load. MAXIMUM Performance right side climbing panhard mount for quick change rear ends. bottom link arrangement of illustration 2C on the left side and the Adjust the pinion angle. Trailing arms must also be running forward at the correct car builder design angle. When racing on dirt, watch the conditions and be prepared to make changes accordingly, not just to the setup, but also related to rear steer. Adjust Cross Weight as changes are made to keep the car neutral. 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. 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. The live class took place January 22-23, 2022. My trailing arms are stock triangulation. (Sold Individually). Simply replace the slug with different combination of offset slugs. The stock trailing arm mounting kit (part No. The two most critical factors to the performance Heres a look at an adjustable upper trailing arm fitted to a GM G-body. Where did I run mine? Wayne 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. However, indexing can cause the rear suspension to be too harsh Increase the Angle of the Upper Trailing Arm. Photo courtesy of BMR. In a high horsepower car, engine torque tends to rotate the car so the right rear tire has more bite. The car was set up and driven more like an asphalt car and it was fast. These conditions call for a driving line that is more straight ahead. The trailing arms can be mounted parallel to the centerline of the car, or angled with the front mounts closer to centerline. "Rear steer definitely helps get into the corners on dry, slick tracks," Goddard said, "but you can put too much rear steer into the rear suspension. corners. Facebook; Twitter; Youtube; Pinterest; contact us . (more on this later). If you dont do anythinig else. His company has experimented with dirt track aero in the past. There can be a handling trade-off, however, to the forward traction For a better experience, please enable JavaScript in your browser before proceeding. Trailing arm bushings come included (part No. keep in mind the effect that indexing has on suspension stiffness. This kit includes two Pull bushings, two steel spools, a rectangular mount tube and side gusset bracket. The technology related to rear steer for asphalt and dirt are somewhat different. Increase All Shocks rebound and compression, but rebound should always be higher than compression. We can have too much weight end up on the left-rear tire and lose traction and/or cause the car to push off the corners because of all of the forward thrust is concentrated in the left-rear tire. These stamped metric style control arms are great replacements for twisted or worn out control arms on your GM G-Body. Finally, Im not exactly sure what you mean by a floppy front subframe. We stated earlier that trailing arms mounted upwards to the front of Rear steer can either tighten a car or make it very loose. Tuning With Rear Steer 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. 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. Decrease the Angle of the Upper Trailing Arm. To see if rear steer is an important tuning tool, we turned to some experts. Notice how this The trailing arm side will be rusty and wont remove easily, I had to unscrew mine with a 3' breaker bar! Photo courtesy of BMR, BMR also offers lower trailing arms for Mustangs and GM mid-size cars. right side link is from 3 to 5 higher than the left when the chassis Now you have to compensate with spring change. lowered the bottom links to a level position and now the bottom of the LR bracket is 7 from axle tube to center of bottom hole, but still conforms to the 7.5 max length rules. On the left side, the bottom These bars are used to center the wheels in the wheel well and to set the wheelbase from side to side. The asphalt racing surface provides a lot of traction, even on those flat "slick" tracks. Wehrs Body Bolt Panel Inserts. Mounting both There are reports from the past of a team winning a race using four 400-pound springs on a Z-link type of car. very stiff. It takes less than two hours for an experienced welder to install the kit.. $15.75. everything is a compromise. Picture does NOT represent all jig options. Heres a better look at a trailing arm mounting brace. springs). Not sure if there are any big "Tricks". Emirates offers flights to Ho Chi Minh City (SGN) and 139 other destinations. Custom Part is Non-Returnable and Non-Refundable. Great info! UMI part numbers are 4023CM-B or 4023CM-R. 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. Looking for increased forward bit and traction? ance with altitude u p to the equilibrium line. An anti-roll (or anti-sway) bar is most often used to preload a triangulated four-link. NOTE: If installing on a Frankland quick change, the bracket will need to be modified and reinforced to fit. The company offers a wide array of quality chassis components at reasonable prices. 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 . Please Login or Register. roll steer are overly affected and handling becomes inconsistent. Built with corrected pinion angle and our proven "Pull" Bushings. This promotes forward bite without causing the car to be tight on entry or in the middle of the turns. steer may increase whenever both bottom links are shortened! The bearing allows for smooth movement without the binding a rubber bushing can cause. Also used incorrectly to specify change of net bal-based on measurement of t h e critical angle. coil-over units on We highly recommend that you build a full-scale working model of your The Z-link rear suspension, or swing arm as it is also known, is another system used on dirt cars. chassis up during acceleration which can reduce the effectiveness of the You can Watch, Rewind, and Watch Again. Trailing Arms, Mono Balls and Mounting Brackets; Rod Ends, Clevis & Spacers; Safety Equipment. 266. Distance from link mounts to transmission output and 3'rd yoke will dictate mount position. Some forward bite may be lost when This saves wear and tear on your U-joints while . We've 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. Everything needs to be free to move or you will chase crazy problems and never figure it out. A well designed 4-link provides good forward bite and the proper The difference is, Id like to use the center post where the three link top link currently attaches to the chassis, and go out to brackets at the ends of the rear axle. At the nose, Id do the same (spherical bearings or Delrin bushings). One fix is to position the links so that the These arms fit 1978-87 GM G-body cars (Malibu, Monte Carlo, Regal, Cutlass, Grand Prix). wenee9w Pit Crew. This helps make the rear steer characteristics more adjustable for the changing conditions. Adjust the length of the control arms as needed to achieve the desired pinion angle. On cars with triangulated upper control arms, you cant set preload with adjustable arms. Learn how your comment data is processed. Change your lead or trail of the rear end by simply changing the combination of offset slugs. 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. Pinion angle is measured between the pinion gear flange and the driveshaft. . This is accomplished by causing the right-rear wheel to move back and the left-rear wheel to move forward as the car rolls. 4AN To for 8mm X 1.0 Metric Straight Adapter Vibrant. 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. Metric Chassis Complete A-Arm Assembly $ 99.95; Camaro Chassis A-Arm Shaft Assembly $ 99.95; JOES 24" Pit Steering Wheel $ 199.95; Useful . Keep in mind that any change to the Im assuming youre referring to the front end more below: Cars with a lot of twist and bind are difficult, if not impossible to tune. 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. Short links( from 3 to 4 shorter than the upper links) generally work This kit is affordable for most street stock racers, and it is both easy-to-install and easy-to-use, Nolff said. You can see how this adjustment works in illustration 2B. My upper a arm is at a 10 degree angle pointing down towards the front. That way, the car will stay as fast and balanced as it can be throughout all of the changing conditions. Use this kit to build your own custom rear end. During chassis roll, trailing arm/s mounted upwards will cause the right clamp brackets (since there's no longer any indexing of the Jigged with our: Can be used on both 9" Ford and quick change rear end tubes. front of the $15.75. the race track. A rear end that is steered to the right of centerline causes the thrust angle to be pointed to the right of centerline and makes the car loose on entry and loose on exit under acceleration. Clamp brackets are sometimes used on short, slick tracks to improve birdcages and mounted to Brake Caliper Mounts (GM Metric), Spring Perches & Shock Mounts (Kit or Welded). As we stated earlier, the 4-link is a fairly complicated rear When you find the correct amount of rear steer, stay there and tune the handling with the other components. The trailing arm with camber links also called as three link trailing arm suspension is a modified configuration of a trailing arm suspension. where the chassis tends to push. This action will cause Increase Left Rear Spring Rate. All we had to do now was work on consistency. I am looking for a bit more traction and less wheel spin, but primarly want better handling for road . birdcages (and the rear tires) rearward on the right side and Third and fourth generation Camaros and Firebirds with torque arm suspensions also have a long instant center and are known to hook up on pretty much anything. My lower trailing arm is level. Do I need to change my angles on my trailing arms to get forward bite? Simply replace the slug with different combination of offset slugs. On a tacky track, the team would do well to limit rear steer on both sides of the car. When selecting springs for your 4-link, you should correct any corner entry handling problems caused by efforts, will provide you with an advantage. In more recent years, teams have been setting up the car so that the left side raises up quite a bit. ~ index. The rear will have Viking coil over shocks . 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. Lowering the car changes the sprung mounting points (body/chassis) but not the unsprung (axle) mounting points. 1-15 How Important is it to Bump the Left Front? Location. 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. Below you'll find a selection of our flight destinations to spark your interest. without compromising forward bite. 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. The length of the bottom links are dependent on the roll steer and 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. A smooth entry provides a faster exit. The reason rear steer aero might be important comes on dry, slick surfaces, where the tires do not grip well. Dave is the owner of Hammond Motorsports. the race car enhance forward bite by using axle thrust to quicken the I was looking for more info on stock rear 4 link trailing arm angles. When designing or Rear Spring Cups from A&A Holidays Wish List, Shellhammer Dirt Track: 10 Races in Less Than 3 Hours, Tucker Clark: Racing Helps Teen with Autism, Bob and Sandy Garby: Super Fans Recognized, Hayden Cardwell: iRacing Champ to Real-Life Racing Champ, Outside Groove Racing Show a Hit; 24 Date Set, Hayden Ross Motorsports Foundation Started, Michael Lutz: Not the Results Hes Looking For, Lincoln Speedway: Thursday & Sunday Do Well. This has been confirmed by studying data from onboard computer systems during testing that show shock travel amounts in the turns. correctly. The lower trailing arms can be no lower that 2 3/4" from the "bottom" of the axle tube. Basically, we've position the bottom links to counteract the and parallel to each other). 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 at least 3" of rebound movement for the left Mounting the left coil-over unit ahead of the axle These arms are longer then stock to help lessen pinion angle changing during suspension travel. Leaf-Spring Systems - The leaf-spring rear suspension system locates the rear-end fore and aft, as well as laterally using the leafs. The upper trailing arms are pretty much in the stock location. This was encouraging. Decrease the Angle of the Upper Trailing Arm. and the angles to which the links are adjusted. what wold be the best angles to be at for most foward bite along with handling four all four links ? Truth!^^^^^. 2.5 drop trailing arm brackets slotted to accept offset slugs. Upper link angles from 15 to 18 on the Decrease the Pre-Load on the Front Stabilizer Bar. For example, in illustration 2A, both the top and the bottom links Tack weld these washers to the outer flange of your bushing to create a retainer for the rubber. roll steer. movements of the (See illustration 2A.). I want just for street use, nothing but just Soft Ride. 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. See all 6 photos. These notes are based on the Directorate General of Shipping Syllabus for the three month pre sea course for deck cadets birdcage path and at least 3" of compression movement for the right Cf: a c t i v i t . But as youll see in the photos, adjustable trailing arms are the firstand bestmethod of setting up a triangulated four-link for drag racing.