Dirt Late Models Crate

Right Rear

Midway in the 2026 season we developed a new right rear shock valving for dry slick tracks. Problem: When tracks get slick and the chassis requires side bite. Mechanics are increasing R.R. Spring rate by adding spring rubbers or installing a stiffer spring. This helps side bite but now hurts forward bite because the stiff springs kills forward bite. Solution: We created a dry slick only shock that sticks the right rear tire on corner entry and has great forward bite. Now it is not necessary to add excessive spring rate to the R.R. and kill your forward bite. You cannot run this shock when the track is fast and heavy because it will make your chassis way too tight.

The standard right rear shock is still great for fast/heavy track conditions. This shock has more high-speed control to stop the oscillation in the rough. Both shocks have plenty of rebound adjustment range to fine tune for the changing track conditions. We always mark your dyno sheets for recommended settings for track conditions.

 

Left Rear

The new FPORS designed for left rear shocks have been a big improvement to this corner of the racecar. These shocks require less gas pressure than even a base valve shock. This design of shock will control attitude of the left rear suspension and not be dependent on excessive gas pressure.

The left rear (behind) shock and spring combination has become more critical than ever before with the requirements on this corner of the race car. Every chassis manufacturer has different heights and load requirements. We can create a good combination for you regardless of the brand of chassis that you are racing.

The left rear front mounted to the axle tube (clamp) shock provides enough extended rate to hold the left rear up and make sure the left rear corner does not fall and let the chassis lose the rear steer. A fine balance of compression dampening and gas pressure provides this combination. This shock’s main function is to create traction from the axle tube rotation. This shock is very critical in making sure you have the correct combination to develop maximum traction.

The left rear (front) birdcage shocks are used on chassis that don’t accept the axle tube shock. This shock is also critical in making sure the left rear corner does not fall and let the chassis lose the rear steer.

 

Right Front

The right front shocks are built with the flat line piston for the most digressive rebound dampening curve. Built with enough rebound to hold the front end down and keep the chassis turning in the middle of the corner, but not so much that it jacks the R.F. down. Too much rebound hurts forward bite, and too little rebound unloads this corner creating a push condition.

The low-speed compression needs to be soft enough to allow the chassis to get down on corner entry and enough high speed to keep the chassis from slamming the bump stop on corner entry. We have built special pistons just for the right front shock to accomplish these requirements.

 

Right Front bump stops

The 50 durometer (orange) urethane bump rubbers work great to provide for travel to keep this corner down and build rate just at the end of to keep the crossmember from bottoming out.

The double bump spring package is still used on rough track conditions to keep from spiking the rate before the crossmember bottoms out. This configuration also still works great on fast high back tracks by building rate at the end of the travel.

 

Fifth coil

The hydraulic (no spring) 5^th coil we build only requires 75 psi. instead of much more pressure of brand x models. This is because we use FPORS design. The hydraulic 5^th coil dampening is set on your load machine (spring smasher) and can be adjusted to the changing track conditions.

The P/D 5^th shock is still a great source of traction through the lift bar. The secret to this unit is to have a stiff rate for instant traction but create enough travel (3” to 3-1/2”in the slick) to make the torque arm pick up the chassis and plant the tires in the track. If you have less than 3” of travel, your chassis will not have maximum traction. We create this combination with the P/D fifth coil assembly. The 1^st inch of travel is the stiffest rate with the 2^nd and 3^rd inch of travel getting softer for maximum travel. These shocks are available in rebound adjustable or non-adjustable models.

 

Left Front

The left front double adjustable shock is available with an internal droop spring to hold cross weight in the chassis. The internal spring length depends on what chassis you are racing to make sure the engagement is correct. The L.F. rebound and the internal spring holds cross weight in the chassis, which creates forward bite. Too much rebound pulls the tire off the ground and makes the chassis push mid-corner to exit.

The compression on the left front is adjusted for corner entry. If the chassis is tight on corner entry, you need to soften the compression. When the track dries out and your chassis gets free on entry, you stiffen the compression. After we dyno your shock, we will send you dyno sheets showing your complete adjustment range and recommend adjustment position.

 

SHOCK DYNO TESTING SERVICE

Now that the racing season is over, this is the ideal time to start preparing for next season. Many of our customers send all their shocks in to be dynoed at this time of the year, so that they can be checked after a long season of racing.  To encourage all our customers to assess their shocks’ condition before the next season, we’re offering a reduced cost for shock dyno services on any A.R.S. shock—only $10 per shock until January 31, 2027. This reduced shock dyno offer will give you a chance to evaluate the condition of your shocks after a season of racing and at the same time review any new valving combinations.

When sending your shocks to us for service, please enclose a note with return address, phone number, and a brief description of what you would like done to your shocks. A shock maintenance form is available from our website. After the shocks are dynoed, we can call you with the results and discuss the outcome of your shocks or any new shock combinations. Many customers send all their shocks to us during this special dyno offer, so send your shocks in as early as possible to avoid any delays in preparing for next season

Eliminates the Need for Left Rear Front Shock

The triple spring combination provides enough extended load to keep the left rear corner up throughout the corner.

The three spring rates lets the left rear corner drop at ride height to allow for maximum spoiler height.

Now the only need for a left rear front shock is an extremely rough track. For these circumstances, install your left rear front shock in full soft position to navigate through the rough conditions.

The left rear shock is available in single or double adjustable. The compression is fine-tuned to help keep the left rear up throughout the corner.

When ordering this combination, know what your extended and ride height shock bolt to shock bolt is on your current left rear back shock.

The Base of the P/D 5th Coil Shock is a Non-Adjustable Small Body Twin Tube 1000 Series Shock.

The compromise of choosing the correct spring for off the corner traction or straight-away traction is over. With the Progressively/Digressive fifth coil assembly you can create the best of both worlds. The P/D unit mounts in the same positions as the conventional fifth coil assembly.

The Problem: A stiff fifth coil springs provides instant traction when the driver starts to pick-up the throttle off the turn, but loses traction halfway down the straight-away, because the rear tires break loose from too much spring rate. A soft fifth coil spring does not hook the rear tires to the ground instantly off the turn, but does provide good traction down the straight-away.

The Cure: The P/D was designed to provide better forward traction off the turn and all the way down the straight-away. The P/D assembly has maximum spring rate the 1st inch of travel, and from 1 inch to 4 inches of travel the spring rate decreases to provide a softer total spring rate. For example a standard 400.b. fifth coil with 3 inches of travel would have a total rate of 12oolbs. The P/D assembly using a 400/300 spring combination with 3 inches of travel would have a total rate of 926lbs.

The P/D assembly is a combination of two springs with a slider assembly held together with a small diameter shock in the center. For the first inch of travel, the fifth coil assembly primarily uses the long spring. After that the additional travel uses the combination of both springs providing the desired spring rate. A small diameter shock in the center of this assembly dampens the spring to control any undesired oscillation.

The Disclaimer: The P/D fifth coil assembly is not a cure for all ill-handling race cars. It will increase forward bite over a standard fifth coil assembly, but it will not take a race car that has poor forward bite because of a bad rear suspensions combination and make a winner out of that car.

The double bump spring allows you to have a dual stage bump spring rate, to keep the front end down. Now you can be as soft as possible, as long as possible, without bottoming out on the cross member.
The outer spring starts compressing the last 1” of travel of the right front. The inner spring engages the last 1/4” to 3/8” of travel. This allows the spring combination to travel more without coil binding the bump spring.
This bump spring package provides 500 lbs. of outer rate at 1” of travel. The inner spring allows up to 600 lbs. of rate the last 1/4” of shock travel. The spring cups provide support for the bump springs.
This system will not work on all shock bodies. You must have 6-1/2” of shock shaft available at ride height.

1″ tall x 2 1/2″ O.D. with 9/16″ center hole for the 2020 World of Outlaws droop stop rule. These straight side bump rubbers fit in most current droop limiters.

Available in (4) durometers and colors.

Black – 30 durometer
Yellow – 40 durometer
Orange – 50 durometer
Blue – 60 durometer

 Package 1 – $3,650
($3,890 with Four C/O Kits)

Fronts – 4200 Series Mono Tube E-Model (Rebound) Adjustable

Left Rear Front – 4200 Series Mono Tube E-Model (Compression) Adjustable

Left Rear Back – 4200 Series Mono Tube E-Model (Rebound) Adjustable

Right Rear – 3200 Series Mono Tube E-Model (Rebound) Adjustable

P/D Fifth Coil

Fronts

The 4200 Series shock is a large body mono-tube (gas) shock with a hard black anodized aluminum body. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts.  These shocks contain the latest T/C valving with a large diameter flat line piston for maximum front grip.  They are E-Model Eye (Rebound) Adjustable that include the new style adjusting wheels that allow the eyes to be removed easily to change bump stops.  This shock utilizes a base valve that is installed between the floating piston and the valving piston to isolate the pressure, allowing for substantial reduction in rod pressure.  These rebound adjustable shocks contain check valves to ensure no bleed-over when adjusting the rebound dampening.  This shock has a Schrader valve that provides for fine tuning the gas pressure.  This shock accepts 2 ½” I.D. or 5” O.D. Springs and is available in 5”, 6”, 7”, 8” & 9” shaft lengths.

Left Rear Back

The 4200 Series shock is a large body mono-tube (gas) shock with a hard black anodized aluminum body. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts. This shock contains the latest T/C valving with a large diameter flat line piston for maximum front grip. This shock is E-Model Eye (Rebound) Adjustable that includes the new style adjusting wheels that allow the eyes to be removed easily to change bump stops. This shock utilizes a base valve that is installed between the floating piston and the valving piston to isolate the pressure, allowing for substantial reduction in rod pressure. This rebound adjustable shock contains a check valve to ensure no bleed-over when adjusting the rebound dampening. This shock has a Schrader valve that provides for fine tuning the gas pressure. This shock accepts 2 ½” I.D. or 5” O.D. Springs and is available in 5”, 6”, 7”, 8” & 9” shaft lengths.

P/D Fifth Coil

The Base of the P/D 5th Coil Shock is a Non-Adjustable Small Body Twin Tube 1000 Series Shock. The P/D assembly is a combination of two springs with a slider assembly held together with a small diameter shock in the center.  For the first inch of travel, the fifth coil assembly primarily uses the long spring.  After that the additional travel uses the combination of both springs providing the desired spring rate.  A small diameter shock in the center of this assembly dampens the spring to control any undesired oscillation.

Left Rear Front

The 4200 Series shock is a large body mono-tube (gas) shock with a hard black anodized aluminum body. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts. This shock contains the latest T/C valving with a large diameter flat line piston for maximum front grip. This shock is E-Model Eye (Compression) Adjustable that includes the new style adjusting wheels that allow the eyes to be removed easily to change bump stops. This shock utilizes a base valve that is installed between the floating piston and the valving piston to isolate the pressure, allowing for substantial reduction in rod pressure. This compression adjustable shock contains a check valve to ensure no bleed-over when adjusting the compression dampening. This shock has a Schrader valve that provides for fine tuning the gas pressure. This shock accepts 2 ½” I.D. or 5” O.D. Springs and is available in 5”, 6”, 7”, 8” & 9” shaft lengths.

Right Rear

The 3200 Series shock is a small body mono-tube (gas) shock with a hard black anodized aluminum body. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts.  This shock is rebound adjustable valved for maximum traction with the latest T/C valving.  This shock is E-Model Eye Adjustable.  The base valve design in this shock allows for very low gas pressure to be used and still function properly.  This shock gives the driver more feel and allows the car to grip the track more.  This shock has a Schrader valve that will accept 10-50lbs. gas pressure which provides for fine tuning the chassis balance.  The small body shock accepts 1 7/8”, 2 ¼” & 2 ½” I.D. Spring & is available in 5”, 6”, 7”, 8” & 9” shaft lengths.