Asphalt Late Model Newsletter
The current valving curve for the left front is a shock with less zero point and more midrange rebound. It has always been a fine balance in providing enough rebound to hold the nose of the chassis down throughout the corner but not too much that it skips across the bumps. This combination is achieved with a piston that is more linear on the rebound. This update can be done to any current left fronts or new shocks. The rebound requirement of this corner depends on several factors. When a stiffer left front bump stop or bump spring is used, less rebound is needed. Because if it does not compress too much, it will not have the energy to extend. A chassis with extra jacking force on the left front suspension requires less rebound on this corner. Some racing series check the chassis ride height when the car comes off the track. All these factors and more must be considered when choosing the rebound for the left front shock. The compression requirements depend on a few factors: track configuration, spring rate, and horsepower of the car. The current chassis requires a soft compression, so the chassis sets down on corner entry especially on lower horsepower cars where not much brake is applied. High bank tracks require additional L.F. compression to keep the chassis from diving and making the car tight on entry.
The current valve curve for the right front shock is less zero point with a flat line piston and very little or no bleeds. The right front demands are different from the left front. The bump stops or bump spring package determines how much rebound is needed. If your chassis setup is dominant on the left front bump you will require less rebound in the R.F. shock than the left front shock. Rebound on the right front makes the front end more positive in the middle of the corner and on corner exit. Too much rebound in the right front will make the chassis free on corner exit. Increased compression on the right front shock tightens the chassis on corner entry to exit. Too soft on R.F. compression will free the chassis throughout the corner. If the right front compression is too soft, more spring is required to keep the chassis from being loose on corner entry.
The level of tuning the chassis balance with the rear shocks has increased in the last couple of years. Balancing the traction generated by the rear shocks and turning in the center of the corner is a fine balance. Many factors, such as the track surface, tire compound, spring package, suspension design, and more, determine how much rear traction is required by the rear shocks. It is important that you let us know this information to achieve this balance.
Increasing the rebound in the left rear shock will create more forward bite and free the chassis up on corner entry. Too much rebound in this shock will make the chassis loose on corner entry especially on older tires. Increased compression on the L.R. shock will free the chassis up on corner entry and make the chassis tighter on corner exit.
Increasing the rebound in the right rear shock has the same results as the left rear shock. Too much rebound in this shock will make the chassis tight in the middle of the corner and on corner exit especially with lower horsepower cars.
Softer compression on this shock will create more grip throughout the corner. Increased compression may be required on low horsepower cars to free up the chassis in the center of corner.
Right Rear Trailing Link
In the few racing series that still allow moveable trailing link, A.R.S. builds the best one. This unit allows you to extend your right-side wheelbase to roll the center of the corner. Then on corner exit, you can shorten the right side wheelbase up to ¾ inch. The internal dampening allows the spring to extend slowly on corner entry and not upset the chassis. If this is legal where you race, you need this in your car.
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, 2024. 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.
Left Rear Shock and Spring Assembly
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.
P/D 5th COIL SHOCK ASSEMBLY
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.
Double Bump Spring for Right Front of Dirt Late Model
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.
Double Spring Combination – Right Rear
The double spring right rear uses a 10” x 100 lbs. inner spring with a 12” x 150 lbs. barrel outer spring. This package provides more forward bite and side bite than a standard 250 lb. spring or 225 lb. with spring rubbers. This unit will provide the same entry rate as a single spring but will have a softer exit rate. The right rear dual springs provide more pressure pushing the tire into the race track. This is achieved by pre-loading the 100 lb. inner spring so pressure is applied even on extension as the car is driving off the corner.
This is designed for dry slick only, middle to bottom of the race track. It will make the chassis tight if the right rear tire hits the cushion. The slicker the track the better this works.
Example of standard right rear versus double spring:
Right rear shock Travel 225 lbs. spring + Double spring
center to center 1 rubber (250 lbs. rate) 100 lbs. + 150 lbs.
21-1/2” 1-1/2” extended 25 lbs. load 224 lbs. load
21” ______1” extended 150 lbs. load _ ____280 lbs. load
20” ride height 400 lbs. load 400 lbs. load
19” 1” compression 650 lbs. load 650 lbs. load
18” 2” compression 900 lbs. load _900 lbs. load
Bump Stop For Droop Limiter
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- $3,200
($3,440 with four C/O Kits)
Fronts – 4000 Series Mono-Tube E-Model Double Adjustable
Rears – 3200 Series Mono-Tube E-Model Double Adjustable
The 4000 Series shock is a large body mono-tube (gas) shock with a hard black anodized aluminum body and canister that is double adjustable. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts. These shocks contain the latest T/C valving for maximum front grip. They are E-Model Adjustable and include the new style adjusting wheels that allow the eyes to be removed easily to change bump stops. The Double Adjustable with the remote canister allows for substantial reduction in rod pressure which provides more grip. This shock allows the racer to adjust the rebound and compression dampening completely independently. This shock allows for the rebound to be adjusted at the eye of the shock and the compression to be adjusted on the remote canister of the shock. This shock has a Schrader valve that allows fine tuning of the gas pressure. This shock will eliminate the need for extra shock inventory by creating one shock for each corner of your car. The large body shock accepts 2 1/4” & 2 ½” I.D. or 5” O.D. Springs and is available in 5”, 6”, 7”, 8” & 9” shaft lengths
The 3200 Series shock is a small body mono-tube (gas) shock with a hard black anodized aluminum body and canister. This shock uses CNC machined aluminum internal parts designed for racing with no aftermarket parts. These shocks contain the latest T/C valving for maximum traction. They are E-Model Eye Adjustable. The base valve design in this shock allows for very low gas pressure to be used and still function properly. When combined with our canister option and the ability to run low rod pressure this shock has virtually no rod pressure build up and allows for maximum grip a driver can feel. This shock has a Schrader valve that will accept 10-100lbs. gas pressure which provides for fine tuning of 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.
Package 2- $2,200
($2,440 with four C/O Kits)
Fronts – 4200 Series Mono-Tube E-Model Single (Rebound) Adjustable
Rears – 3200 Series Mono-Tube E-Model Single (Rebound) Adjustable
The 4200 Series shock is a large body mono-tube (gas) shock with a hard black anodized aluminum body and canister if choosing that option. 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 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.
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. These shocks are rebound adjustable valved for maximum traction with the latest T/C valving. They are 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.
In addition to your shock package you may also want:
Gas Gauge 100 PSI (ARS #40887)
Coil-Over Kit (ARS #301045)
Coil-Over Kit (ARS #40101T)
(Any package can be customized for your specific needs, ask how when you call to order!)