KellTrac 4/8 Adjustable Lowering Kit w/ Hybrid Bushings, STREET Series (KTI-15F150-48-ST) - 2015-2026 Ford F-150
Improve the stance, handling, and traction of your 2015-2026 Ford F-150 with the KellTrac STREET Series Adjustable 4/8 Lowering Kit. Developed for enthusiasts who want improved suspension performance without sacrificing everyday ride comfort, this kit combines ride-height-adjustable front coilovers, double-adjustable Viking shocks, and a rear leaf spring flip kit to deliver a lower stance with extensive suspension adjustability.
After more than a year of development and testing, KellTrac engineered this system specifically for the F-150's leaf spring suspension. Featuring application-specific Viking WARRIOR shock valving, custom Landrum springs, hybrid bushing technology, and adjustable compression and rebound damping, the kit allows drivers to fine-tune suspension performance for daily driving, street performance, and drag strip conditions.
Adjustable 4/8 Lowering System
The KellTrac STREET Series kit is designed to provide an aggressive lowered stance while maintaining suspension adjustability and ride quality.
The front ride-height-adjustable coilover system allows the front suspension height to be adjusted to suit individual preferences. Adjustable front coilover mounting positions provide additional flexibility while increasing available front shock travel compared to other lowering options.
At the rear, the included leaf spring flip kit provides the lowered ride height while retaining the factory-style leaf spring suspension configuration.
Front Double-Adjustable Viking Coilover System
The front suspension features a ride-height-adjustable, double-adjustable coilover system utilizing Viking WARRIOR shocks and custom Landrum springs.
The shocks feature application-specific valving, stroke, and construction developed to provide improved suspension control and traction.
Independent compression and rebound adjustments allow drivers to fine-tune suspension response for different driving conditions and track surfaces.
The included front coilover conversion mounts feature adjustable shock positioning, providing increased suspension travel and additional setup flexibility.
Rear KellTrac Double-Adjustable Viking Shocks
The rear suspension utilizes KellTrac-specific double-adjustable Viking shocks mounted in the factory shock locations.
These shocks feature valving specifically developed for the F-150's leaf spring suspension, allowing drivers to adjust compression and rebound damping to improve traction and suspension response.
The stock-location configuration maintains the factory shock mounting arrangement while providing additional suspension tuning capability.
Bilstein high-density foam shock bumpstops and Monroe shock dust boots are included as standard equipment.
Hybrid Bushing and Bearing Design
This STREET Series lowering kit combines durable spherical bearing front coilover mounts with high-durometer polyurethane rear shock bushings.
The front spherical bearing mounts provide precise suspension movement and improved performance, while the rear polyurethane bushings are designed to maintain ride comfort and durability.
This hybrid approach balances suspension responsiveness with the comfort needed for street-driven applications.
Rear Leaf Spring Flip Kit and Pinion Angle Correction
The included rear leaf spring flip kit provides the rear lowering components needed for the 4/8 suspension configuration.
A rear pinion angle correction kit is included to help address driveline geometry changes associated with lowering the truck.
The kit also includes a transmission shim kit for applications where additional driveline adjustment is required, along with extremely low-profile rear bumpstops and new rear leaf spring mounting hardware.
Adjustable Camber Correction
A front control arm adjustable camber kit is included to assist with alignment after lowering the truck.
KellTrac notes that maximum front camber adjustment averages approximately -2.00 degrees. Achieving less negative camber may require additional adjustable upper control arms or modification of the mounting holes.
Street and Drag Strip Performance
The KellTrac STREET Series kit was developed and tested specifically for street and drag strip applications, including prepared and no-prep racing surfaces.
Its adjustable shock valving allows drivers to change suspension behavior based on traction conditions, helping optimize weight transfer, handling, and overall vehicle feel.
Whether the truck is used for daily driving or drag racing, the system provides the flexibility to adjust ride quality and suspension performance.
Kit Includes
- Front ride-height-adjustable, double-adjustable coilover system
- Front coilover conversion mounts with adjustable shock positioning
- Front control arm adjustable camber kit
- Rear stock-location KellTrac double-adjustable Viking shocks
- Bilstein high-density foam shock bumpstops
- Monroe shock dust boots
- Rear leaf spring flip kit
- Rear pinion angle correction kit
- Transmission shim kit for use when required
- Extremely low-profile rear bumpstops
- New rear leaf spring mounting hardware
- Required installation components and hardware
Features
- Designed for 2015-2026 Ford F-150 applications
- STREET Series adjustable 4/8 lowering kit
- Developed and tested specifically for street and drag strip use
- More than one year of suspension development and testing
- Collaboration involving KellTrac, Viking Performance, and UMI Performance
- Front ride-height-adjustable Viking coilover system
- Double-adjustable front and rear shock damping
- Independent compression and rebound adjustments
- Application-specific Viking WARRIOR shock valving, stroke, and design
- Custom Landrum springs specified for the application
- Front coilover conversion mounts with adjustable shock positioning
- Increased front suspension travel compared to other lowering options
- Durable spherical bearing front coilover mounts
- High-durometer polyurethane rear shock bushings for ride comfort
- Rear Viking shocks retain the factory mounting locations
- Shock valving developed for leaf spring suspension
- Lightweight CNC-machined components
- Front adjustable camber correction kit included
- Rear leaf spring flip kit included
- Rear pinion angle correction components included
- Transmission shim kit included for use when necessary
- Bilstein high-density foam shock bumpstops included
- Monroe shock dust boots included
- Extremely low-profile rear bumpstops included
- Designed to improve handling, traction, and suspension feel
- Adjustable for prepared and no-prep track surfaces
- Allows ride quality and performance adjustments
- Assembled in-house and ready for installation
- Precision-fit components designed for consistent performance
- Estimated installation time of 3-5 hours
- All required installation components included
Fitment
- 2015 Ford F-150
- 2016 Ford F-150
- 2017 Ford F-150
- 2018 Ford F-150
- 2019 Ford F-150
- 2020 Ford F-150
- 2021 Ford F-150
- 2022 Ford F-150
- 2023 Ford F-150
- 2024 Ford F-150
- 2025 Ford F-150
- 2026 Ford F-150
Important Fitment and Installation Notes
Towing Restriction: This lowering kit was not designed for towing applications.
Frame Modification: Frame notching may be required in some applications to provide adequate suspension clearance.
Camber Adjustment: Maximum front camber adjustment averages approximately -2.00 degrees. If less negative camber is desired, adjustable upper control arms or slotting of the mounting holes may be necessary.
Ride Height: The kit features adjustable front ride height and can be configured to suit individual lowering goals within the system's adjustment range.
Intended Use: Designed and tested only for street and drag strip applications, including prepared and no-prep racing surfaces.
Installation: KellTrac estimates a 3-5 hour installation. All required installation components are included. Additional frame or alignment modifications may be necessary depending on the application.
Vehicle Configuration: Confirm drivetrain, cab configuration, and any application-specific restrictions with KellTrac before ordering, as the supplied fitment information does not specify these details.
Kelltrac Terms Of Service
Kelly considers his Kelltrac line to be a specialty line for a unique customer base and has his own terms of service in addition to Beefcake Racing's. You must accept these terms on all Kelltrac orders. Please read shipping times, cancellation, and returns. If time is of the essence, we do have other options that can ship right away / quicker. Just reach out to one of our sales associates at Beefcake Racing.
Cancellations & Returns
KellTrac Innovations does not accept product returns. Once your order ships, you own it and we will not accept it back - NO EXCEPTIONS. We do not accept order cancellations after the product has shipped. If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
Due to the custom nature of our business and product offerings, we charge a 20% order cancellation fee, period, non-negotiable, no matter who you are. Orders can only be cancelled before the product ships. We do not accept order cancellations after the product has shipped. If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
Leadtime
Please be aware that most orders ship within 2-4 weeks. In some (rare) cases, orders can take up to 6-8 weeks to ship. Holidays can severely impact these lead times. *DO NOT CONTACT US ABOUT YOUR ORDER UNLESS IT IS OLDER THAN 20 BUSINESS DAYS!* If you understand and accept this please check the box and continue checking out. If you do not accept this, please stop and discontinue the order process. Thanks!
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