Product Details
RS-R Down Sus lowering springs for the 2015-2023 Ford Mustang Ecoboost drop the car into a cleaner, more purposeful stance while tightening body roll and sharpening turn-in on everyday roads. Each set is engineered specifically for this Mustang chassis, so drop, spring rate and factory damper tune stay in balance — the car sits where you want it and still drives like a daily.
Racing Studio-R built its first suspension in Osaka in 1972 and has been refining the Down Sus spring for more than fifty years. Each set is progressive-rate, cold-wound and heat-treated in-house in Japan, then matched to the factory shock valving and ride-height target of the specific chassis it bolts onto. Backed by RS-R’s 3-year / 50,000 km fatigue warranty.
Features
- Progressive-rate coil tuned to the factory damper
- Vehicle-specific drop and rate — no universal cuts
- Cold-wound from high-grade SAE alloy steel
- Powder-coated for long-term corrosion resistance
- 3-year / 50,000 km RS-R spring-fatigue warranty
- Made in Osaka, Japan
Availability
This application is a special-order item. Lead time from Japan is approximately 3–6 months by standard sea freight. Expedited DHL/FedEx/UPS shipping from Japan is available for an upcharge when stock is on hand — contact us for current lead time.
Specifications
| Part Number | FO110D |
| Part Name | RS-R Down Sus Lowering Springs |
| Vehicle | 2015-2023 Ford Mustang Ecoboost |
| Ride-Height Adjustable | No |
| Spring Type | Progressive |
| Approximate Drop - Front | -25mm to -30mm (-1.0inch to -1.2inch) |
| Approximate Drop - Rear | -25mm to -30mm (-1.0inch to -1.2inch) |
| Spring Rate - Front | 2.94 Kg/mm |
| Spring Rate - Rear | 11.20 Kg/mm |
| Warranty | 3 Years / 50,000 km |
Vehicle Fitment
- 2015 Ford Mustang Ecoboost
- 2016 Ford Mustang Ecoboost
- 2017 Ford Mustang Ecoboost
- 2018 Ford Mustang Ecoboost
- 2019 Ford Mustang Ecoboost
- 2020 Ford Mustang Ecoboost
- 2021 Ford Mustang Ecoboost
- 2022 Ford Mustang Ecoboost
- 2023 Ford Mustang Ecoboost

