KT423 Kits:
Global West Suspension has introduced the ultimate A-body handling package that uses the original frame. The kits are called KT423 Negative Roll Systems. The term negative roll comes from the fact that negative camber keeps the tire flatter on the pavement during cornering. Negative roll systems generates negative camber through the geometry as the tire moves up into the fender. One of the key components to the kit is the spindle Global West developed for A-bodies. The spindle, a forged aluminum spindle is modular and is substantially different from the factory units or any other on the market. Global West uses their own inclination angle and spindle heights along with a special upper control arm kit number CNR-423, lower control arm CNR-42L, H, or EXT and steering linkage. The modular spindle also allows Global West to supply a steering knuckle arm that provides near zero bump over 4 inches of travel. In fact less than .030 of toe change over the entire 4 inches. The Ackerman is also addressed and improved. The end result is dramatic handling improvements.
A Little History
Traditionally tall spindles off of F-body or B-body donor cars where used starting back in the mid 80's. There are several benefits including bigger brakes, better handling, and better tire life because of the camber curve change. Some limitation also occurred like reduced steering response, reduced turning radius, and increased bump steer. However, the bump steer was not much different from stock. All the past limitations have been addressed and dramatic handling improvements are achieved.
The heart of the system GWLSA-1 Spindle and Modular Components:
The new patent pending modular spindle has been in the works for sometime. The spindle is a key component of the geometry that makes the system work. The modular spindle provides Global West a way to address roll centers, camber curve, bump steer, Ackerman, steering ratio, and reduce unsprung weight. Additionally, all the street kits are a bolt on installation. The auto cross / road racing kits do require some frame modifications. Various disc brake kits, either Wilwood or Baer, can be used with a special disc brake bracket from Global West for the application. This spindle will also replace many discontinued spindles on several GM 70's, 80's, and 90's models. Global West is currently designing components for these vehicles.
Tire and Wheel Information:
The minimum wheel diameter that can be used with these KT423 kits using 13 inch brakes is a 17 inch diameter wheel. The maximum back space is 6 inches. On many applications we will use a 17 x 9 1/2 wheel with a 6 inch backspace. The tire is a 275 x 40 x 17. You can run larger tire and wheel combinations, such as 18's or larger, but the backspace is still 6 inches. If you use a greater backspace the limitations will be the tire interfering with the frame and the sway bar during sharp turns.
Steering Information:
A fast ratio steering box is required for autocross/road racing and performs well on the street. However, fast ratio gear is not mandatory for the street due to the fact that KT423 kits do not slow down the steering input, as did the b-body and f-body spindles. If you are looking for the best you can get, by all means a fast ratio steering box is needed. The fast ratio gear we use is ST-42.
The stock center link / drag link, idler arm, and inner tie rods are retained. The tie rod adjusting sleeve and the outer rod end is replaced with our kit ADJ-423. This kit is specific for the KT423 kits. And if you are interested in replacing all the steering components during your build up, Global West offers all the necessary components for your application.
Spring and Sway Bar Selections:
Global West has per-determined spring rates and sway bar combinations for various street applications. However, Global West can supply different springs and/or sway bars based off of your intent with the car. If you have a specific situation, please contact Global West tech department for assistance. Road racing and autocross cars do have options with spring rate and sway bar sizes at the time of the order. Collaboration with Global West Tech will help with your choices.
Lower Control Arm Selection:
There are three different lower control arms available for this system. The first uses a stock type spring and shock combination Part # CNR-42L. The second uses a coilover shock and conical wound spring that indexes in the frame and adjusts the ride height on the shock body. This is a hybrid type coilover that uses the stock spring mount in the frame. There are no frame modifications required for installation. The part number for this lower arm is a CNR-42H. The third lower control arm design is for a coilover. However, the lower arm has the shock mount lowered in the control arm for more shock travel. This design is standard for autocross and road racing cars using KT423 kits.
Upper Control Arm:
The upper control arm is Part # CNR-423. It is a Generation 3 Negative Roll control arm. It is different from the prior Generation 1 and 2 Negative Roll upper arms. The design of the arm has changed to accommodate the COF-42 coilover extended travel frame kit. The COF-42 kit raises the shock and spring location on the frame. This is to achieve more shock travel and converting over to a true coilover application. One of the problems when you are cornering at higher speeds, the a-body vehicles will lift off the ground the front inside tire. The reason, there is not enough shock travel. Our test cars all had the problem until we designed the cof-42 kit. The combination of using the COF-42 and the EXT lower control arms, provide us with a shock length that solves the problem.
Shocks:
The shock brand currently being used for street coilover and standard spring applications is Viking. Qa-1 shocks can be substituted at the time of your order. There will be a price difference between the two brands. The coilover autocross and road racing KT423 kits all come with special valved Penske racing shocks.
Brakes:
Currently, Wilwood 13 disc brakes are standard with all the KT423 kits. Baer brakes are a option. The Wilwood 13 inch brake comes with a 6 piston caliper, cross drilled / grooved black rotors, hubs, bearings, seals, 1/2 inch wheel studs, pads, brackets and hardware. Global West also includes front braided steel brake lines. Note: 17 inch diameter wheels, or larger, are required for brake clearance.
Recap, What comes in the KT423 Kits:
Global West has standardized the KT423 kits with the following components:
KT423 kits include:
Upper control arms specifically built for the system --- CNR-423
Lower control arms – for your specific option (standard spring, coilover, or extended travel coilover)
Front sway bar – size based on option
Front shocks – standard or coilover depending on the option. Brands are Viking for street application, and Penske for autocross and road racing coilover applications. Qa-1 shocks are a option.
Front springs – standard or coilover depending on the option.
Adj-423 – tie rod adjuster and outer rod end assembly
Modular Aluminum forged spindles
Steering knuckle arms for modular spindle
Brake brackets for modular spindle
Wilwood 13 inch 6 piston disc brakes with cross drilled rotors
Front brake hoses to calipers
The spindles and brake assembly are fully assembled.
Hardware
The following kits on this page have several different options based on small block, big block, year, standard spring, coilover shock/spring, extended coilover, street, or autocross/road race.
1964-67 A-Body
#KT423-SC47S Small Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-SC47B Big Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-SC47P Small Block/ Coil Spring (Double Adjustable Viking Shocks)(Pontiac only)
#KT423-CO47S Small Block/ Coilover hybrid type (Double Adjustable Viking Shocks
#KT423-CO47B Big Block/ Coilover hybrid type (Double Adjustable Viking Shocks)
#KT423-PK40S Small Block/ Full Coilover with extended travel lower control arms (Double Adjustable Penske Shocks)
#KT423-PK40B Big Block/ Full Coilover with extended travel lower control arms (Double Adjustable Penske Shocks)
1968-70 A-Body
#KT423-SC80B Big Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-SC80S Small Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-CO80B Big Block/ Coilover (Double Adjustable Viking Shocks)
#KT423-CO80S Small Block/ Coilover (Double Adjustable Viking Shocks)
#KT423-PK40S Small Block/ Coilover (Double Adjustable Penske Shocks)
#KT423-PK40B Big Block/ Coilover (Double Adjustable Penske Shocks)
1971-72 A-Body
#KT423-SC12B Big Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-SC12S Small Block/ Coil Spring (Double Adjustable Viking Shocks)
#KT423-CO12B Big Block/ Coilover (Double Adjustable Viking Shocks)
#KT423-CO12S Small Block/ Coilover (Double Adjustable Viking Shocks)
#KT423-PK12S Small Block/ Coilover (Double Adjustable Penske Shocks)
#KT423-PK12B Big Block/ Coilover (Double Adjustable Penske Shocks)
