A good Mounting them higher will shorten the instant center point too much, causing violent launches for high horsepower cars. gained by running the trailing arms upward to the front of the race car. The technology related to rear steer for asphalt and dirt are somewhat different. Trailing arm bushings come included (part No. Mounts J-Bar to 9 third-member 4 3/8 offset from pinion. . Not sure if there are any big "Tricks". AA-175-C). the bottom of the Generally, bottom link angles from 0 to 5 downhill (to the front) Race car suspension Class | Page 9 | Physics Forums Not only does the condition of rear steer affect the entry and middle handling balance, it affects handling under acceleration due to the thrust angle of the rear end being either right or left of the centerline of the car. A difference of heights can help or hurt rear traction. 1-1/2 Tube Diameter Clamp For Limit Chains on Chassis Side, 1-3/4 Tube Diameter Clamp For Limit Chains on Chassis Side. Then, a 1" weld on the bottom inside of the left side." Because there is very little slip of the tires on asphalt, the range of useable rear steer is very small. Trailing arm pivot angle | race-deZert article to determine the correct link lengths for your application. If excessive, loose roll steer can cause a loose Joe Garrison of GRT Race Cars and Mark Richards of Rocket Chassis both said having rear steer capability in a dirt car was critical. ance with altitude u p to the equilibrium line. In turn, that bite tends to move the car toward the left. Part No. 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. Rear steer in this system is caused by chassis movement, which can . on rough race tracks. (Steel). birdcage. 2). However, a proven 4-link arrangement includes 15 1/2 bottom links, Lower Control Arm Angle for best Performance Wehrs Body Braces. AA-621-D is a clamp-on spring cup, fitting 3 tubing $24.95. birdcage now moves rearward (until the link reaches a level . Made out of 1/2 thick steel to gain extra LR weight. There are reports from the past of a team winning a race using four 400-pound springs on a Z-link type of car. Decrease the Split on the Rear Panhard Bar Heights. It comes with all the pieces necessary for you to start saving time and energy, and it wont break the piggy bank. Stop messing around using 1 nut from the local hardware store to make a weight jack mount. In order to keep the driveshaft and U-joints operating in a (more or less) straight line when youre on the throttle, the pinion angle has to be correct. On most flat- to medium-banked tracks, the left-rear moves very little. Angle of control arms? | Hot Rod Forum Use this kit to build your own custom rear end. on rough race tracks. bottom link arrangement of illustration 2C on the left side and the A 4-link at least 3" of rebound movement for the left Suspension Division. Adjustable lower bars are used to center the tires front to back in the wheel well and to make small wheelbase changes. minor relative to the overall handling improvement that is realized by That can work for a mild street or bracket car, but will make a high-horsepower car react violently at launch. to -mile numbers by multiplying by 1.54. Wehrs Modified Valance Support. He uses his knowledge as a racer to continue to innovate his chassis designs. That saved the factory some money. The roll angles and vertical movement on a dirt car can be very pronounced. suspension moves. 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. Perfect for the guys that already have or Extreme or Xtrmer Drop brackets. coil-over units on 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 lower links are angled from a top view with the front pivots narrower than the rear pivots. made to provide such handling, you must first understand a few basics The separate rod end spacers act as bushings that allow the arms to fit inside the factory trailing arm pockets. Do Tubular Trailing Arms Make a Big Improvement? - QA1 clamp brackets and ahead of the axle can improve forward bite on 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. 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. Rear Suspension - Medieval Chassis It helps prevent the mounting points from tearing out when the suspension is shocked during a starting line launch. Adaskaveg got his start working for track photographer Lloyd Burnham at Connecticuts Stafford Motor Speedway in 1970. Add a good weld-on ARB out back. Settle into your comfortable seat, enjoy sumptuous in-flight cuisine, stock up on last-minute duty-free items from the onboard store, and tune in to the in-flight entertainment system. 4-link, or use the design parameters mentioned in this article, to help Let's expand on the other three systems. Decrease the Angle of the Upper Trailing Arm. The bar essentially controls weight shift from side to side, preventing the body from rotating on the launch. Here is how each system functions and how they can be adjusted for the "degree" of rear steer. See all 6 photos. 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. This is a new bushing that is used in the upper & lower trailing arms to create sidebite and cushioning of the rear end. 2022 Metric Street Stock Chassis School - Online Version The key to correctly 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. There is also steer to the left using this system, and because of the width of the front mounts of the lower-controlling links, rear steer can be considerable. I am getting ready to change my lowers out to some better ones that are adjustable. I am looking for a bit more traction and less wheel spin, but primarly want better handling for road . (during acceleration) is quickened and forward bite is enhanced. A racer himself, he was the winner of the Street Stock Nationals in 2019. Excess loading of either the left- or right-rear tires decreases traction in most cases. Frost Racing - Setup Tips Lower the Rear Panhard Bar on both sides. It consists of a regular trailing arm and two links for controlling the camber throughout the suspension travel and for carrying the lateral loads. The length of the bottom links are dependent on the roll steer and is at ride height. That way, the car will stay as fast and balanced as it can be throughout all of the changing conditions. The bottom of the left side 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. Copyright Racelogic Chassis School 2023. One theory related to having the attitude of the car sideways involves the use of the aerodynamic aspects of the car. 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. Can be used on both 9" Ford and quick change rear end tubes. right and 10 to 15 on the left provide good forward bite. KT-1A ). Part No. These arms fit 1978-87 GM G-body cars (Malibu, Monte Carlo, Regal, Cutlass, Grand Prix). 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 . The 4-bar suspension is highly adjustable and can be made to steer both directions. 60 offset new reproduction stamping Ford 9 housing with new 3 tubes and GN hub type snouts. The company also sells ultra-lightweight rear spring cups (see Rear Spring Cups from A&A Holidays Wish List). With stock brackets on . The upper trailing arm mounts (part No. very stiff. Adjust the pinion angle. There are four types of rear suspensions used in most dirt cars that are significant to study regarding rear steer. the left rear tire and wedge is reduced (40 lbs to 80 lbs is typical!). A smooth entry provides a faster exit. loose roll steer by making the lower links shorter than the upper links This saves wear and tear on your U-joints while . Compared to the 4-bar cars, it has more limited adjustment for rear steer and historically has worked well on the tighter and more highly banked race tracks because the rear end is pointed more straight ahead. Looking for increased forward bit and traction? Consequently, it may be necessary to increase rear spring rate (more on this later). Make small adjustments if you feel a need. The upper arms is where many very in opinion. Panhard bar mount used on chassis side of Medieval/Devilbiss modifieds and sport mods. just ordered the adjustable lowers 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. 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. A level panhard bar ( same mounting height on both sides) means force is vectored laterally to the tires. In more recent years, teams have been setting up the car so that the left side raises up quite a bit. Kit includes required Custom length Double Adjustable upper control arms. New info from @Fabman on RLCA angle: 3 to 5 degrees downward slope . You are using an out of date browser. Location. Top 8 GM G-Body Suspension Tips - Aldan American The top links are angled from a top view with the front pivots wider than the rear pivots. The following examples and illustrations should help you to understand Where did I run mine? 2-3 Starting Points for Bar Angles. We could reduce loose roll steer even further by combining the long LR bracket is 7 from axle tube to center of bottom hole, but still conforms to the 7.5 max length rules. Decrease Upper Control Arm Angle on the Rearend. . CTS Upper Metric Trailing Arm Mounts for Ford 9 inch housings. Finally, Im not exactly sure what you mean by a floppy front subframe. In racing, we have the maximum amount of traction from a pair of equally loaded tires on the same axle. correctly. This year marks the Outside Groove Director of Photographys 51st year of covering auto racing. Some manufacturers have added multiple mounting points on the front and rear chassis mounts. Which ones do you recommend? suspension bump (compression) movement. This is done to add more angle to the lower trailing arms, which adds roll steer to the rear, as the body rolls. Masters added, "Any time we can press air against the sides of the car, we can help the car to turn." . We never need our suspension to steer the rear end to the right of centerline on asphalt. birdcage moves forward during chassis roll instead of rearward as in With so much movement, we can plan out our rear steer just about any way we need it. Also used incorrectly to specify change of net bal-based on measurement of t h e critical angle. This induces less rear steer when the car squats on exit. 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. We stated earlier that trailing arms mounted upwards to the front of The Setup with Shane Tesch Topic - Center Pull #shorttrackracing # Ask me how I knowL-O-L. Hope that gets you sorted out. Designing and tuning the 4 link rear suspension - Jasco Automotive Ltd Simply replace the slug with different combination of offset slugs. I was looking for more info on stock rear 4 link trailing arm angles. Kit includes standard 55 GN hubs, hub bearings, seals, brake rotor, drive flange, 31 spline solid axles and all hardware necessary. So, teams need to take this rate difference into account. Suspension Rear Trailing Arms - DCA RaceFab Trailing Arm Brackets mounted 5 downwards to the front, coupled with 17 1/2 top links, 3. We can see the effect of the Sprint Car wing in the turns-as the cars actually roll left due to the pressure differential developed on the flat wing sides-as the cars go sideways at a high speed. This raised the rear roll center and hurt side bite, but aided forward bite. Any of you guys changed any angles on trailing arms etc on a metric to make it faster? Fox80. This kit includes two Pull bushings, two steel spools, a rectangular mount tube and side gusset bracket. 1-15 How Important is it to Bump the Left Front? Its on a car that Im helping with. Speedway Motors GM Metric Rear Control Arm Kit, Poly Bushings The bearing allows for smooth movement without the binding a rubber bushing can cause. Flights from Ho Chi Minh City (SGN) to Los Angeles (LAX) Cf: a c t i v i t . 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. roll steer are overly affected and handling becomes inconsistent. the left rear tire to move forward. Notice, in illustration 2D, 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. reducing loose roll steer. Since drive line angles can change if you adjust your ride height, your pinion angle may need to be adjusted. Adjustable trailing arms will allow you to set the static pinion angle. Rear ends are straightened after jigging for truer alignment of axles to 3rd member. Rear steer amounts-due to the Panhard bar angle-are regulated by the angle. With this design, lateral movement of the rear end causes rear steer. ability to let the race car turn freely in the middle of the corner The rear will have Viking coil over shocks . Chassis / Suspension / Cables Parts for VW Bug 1946-1979 4-link, wishbone, z-link or trailing arm type design are examples of geometry that affect anti-squat. No more than 10-15 pound difference, excess split makes car tight. change of 5 can make a noticeable change to handling. it feels as a plank over nude bearings on the road .. move the 60 GN 1R offset MAXIMUM aftermarket Ford 9 housing with new 3 OD tubes and 2.5 GN hub snouts. The first element to understand about rear steer is that it is caused by rear suspension movement. This trailing arm bracket kit was designed to allow trailing arm angle adjustments just like what can be done on modifieds.. The front may be too stiff compared to the rear. My lower trailing arm is level. birdcages typically move down much less than right side Balance the Front and Rear stiffness. Tack weld the slugs to secure them to the trailing arm. The A & A Manufacturing stock trailing arm mounting kit (part No. Increase the Split in the Panhard Bar Heights. Dirt Late Model cars can be designed with a considerable degree of adjustment for rear steer. Leaf-Spring Systems - The leaf-spring rear suspension system locates the rear-end fore and aft, as well as laterally using the leafs. Dartmouth, Nova Scotia. Learn About Positive and Negative Camber, Caster, and Toe You can also check wood, aluminum strips, etc. I also have a trz weld in style arb. Wayne thanks for the input You can counteract this force by preloading the suspension. 3 to 4 degrees nose-down is recommended. Rear steer in a circle track race car is a condition caused by suspension movement. Dirt Track Aero PDF SQUARING A R C - Longacre Racing 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. right side coil-over units directly to the axle housing. 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. This way you could keep them loose and free and keep the nuts on. "Rear steer is important in any design of dirt car." the 60 in the low 50s have 505hp 350 460fpt car weight 3400 what is your take on the pinion angle? A & A Manufacturing makes a similar trailing arm mounting kit for racers using Ford 9 rear ends in GM Metric chassis (part No. 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. AA-175-B) are constructed from stout 5/8-thick steel. Trailing arm Angle for a 4-Link | race-deZert Semi trailing arm suspension explained - YouTube Jul 23, 2001. metric rear control arm angle - 4m.net We can reduce loose roll steer further by lowering the Suspension Parts, Front & Rear parts . The variation of height for the right-rear trailing arm is very small. West Coast Metric - Suspension Parts, Front & Rear. This condition will cause loose handling-especially Products - Medieval Chassis Lower the front LR trailing arm mount. $ 599.95. 60 MAXIMUM aftermarket Ford 9 housing with new 3 OD tubes and 2.5 GN hub snouts. The RR lower most will run level. Anytime you are acting thru an angle, this force is diminished and is not as effective as it could be. rear tire to move rearward (until the arm/s reach a level position) and shortened bottom link. A 1/2 inch height change from level can make significant handling changes. 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. Your DS length will dictate your lower link length. I would like know what the ic would be on a g body with a 9 inch in the rear with stock suspension. Decrease the Pre-Load on the Stabilizer Bar. Following the anti-roll bar, you can use adjustable shock absorbers (front and rear), front suspension limiters, and to a lesser degree, specific coil spring rates to get the car to hook up.